:drunk: Write shit code trying to split up the Auth (WIP)

DysonNetwork.Pass/Features/Account/Controllers/AccountController.cs

@@ -0,0 +1,176 @@
+using System.ComponentModel.DataAnnotations;
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Pass.Features.Auth;
+using DysonNetwork.Common.Models;
+using DysonNetwork.Pass.Features.Account.Services;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Account.Controllers;
+
+[ApiController]
+[Route("/accounts")]
+public class AccountController(
+    PassDatabase db,
+    AuthService auth,
+    AccountService accounts,
+    AccountEventService events
+) : ControllerBase
+{
+    [HttpGet("{name}")]
+    [ProducesResponseType<Common.Models.Account>(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult<Common.Models.Account?>> GetByName(string name)
+    {
+        var account = await db.Accounts
+            .Include(e => e.Badges)
+            .Include(e => e.Profile)
+            .Where(a => a.Name == name)
+            .FirstOrDefaultAsync();
+        return account is null ? new NotFoundResult() : account;
+    }
+
+    [HttpGet("{name}/badges")]
+    [ProducesResponseType<List<Badge>>(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult<List<Badge>>> GetBadgesByName(string name)
+    {
+        var account = await db.Accounts
+            .Include(e => e.Badges)
+            .Where(a => a.Name == name)
+            .FirstOrDefaultAsync();
+        return account is null ? NotFound() : account.Badges.ToList();
+    }
+
+    public class AccountCreateRequest
+    {
+        [Required]
+        [MinLength(2)]
+        [MaxLength(256)]
+        [RegularExpression(@"^[A-Za-z0-9_-]+$",
+            ErrorMessage = "Name can only contain letters, numbers, underscores, and hyphens.")
+        ]
+        public string Name { get; set; } = string.Empty;
+
+        [Required] [MaxLength(256)] public string Nick { get; set; } = string.Empty;
+
+        [EmailAddress]
+        [RegularExpression(@"^[^+]+@[^@]+\.[^@]+$", ErrorMessage = "Email address cannot contain '+' symbol.")]
+        [Required]
+        [MaxLength(1024)]
+        public string Email { get; set; } = string.Empty;
+
+        [Required]
+        [MinLength(4)]
+        [MaxLength(128)]
+        public string Password { get; set; } = string.Empty;
+
+        [MaxLength(128)] public string Language { get; set; } = "en-us";
+
+        [Required] public string CaptchaToken { get; set; } = string.Empty;
+    }
+
+    [HttpPost]
+    [ProducesResponseType<Common.Models.Account>(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    public async Task<ActionResult<Common.Models.Account>> CreateAccount([FromBody] AccountCreateRequest request)
+    {
+        if (!await auth.ValidateCaptcha(request.CaptchaToken)) return BadRequest("Invalid captcha token.");
+
+        try
+        {
+            var account = await accounts.CreateAccount(
+                request.Name,
+                request.Nick,
+                request.Email,
+                request.Password,
+                request.Language
+            );
+            return Ok(account);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    public class RecoveryPasswordRequest
+    {
+        [Required] public string Account { get; set; } = null!;
+        [Required] public string CaptchaToken { get; set; } = null!;
+    }
+
+    [HttpPost("recovery/password")]
+    public async Task<ActionResult> RequestResetPassword([FromBody] RecoveryPasswordRequest request)
+    {
+        if (!await auth.ValidateCaptcha(request.CaptchaToken)) return BadRequest("Invalid captcha token.");
+
+        var account = await accounts.LookupAccount(request.Account);
+        if (account is null) return BadRequest("Unable to find the account.");
+
+        try
+        {
+            await accounts.RequestPasswordReset(account);
+        }
+        catch (InvalidOperationException)
+        {
+            return BadRequest("You already requested password reset within 24 hours.");
+        }
+
+        return Ok();
+    }
+
+    public class StatusRequest
+    {
+        public StatusAttitude Attitude { get; set; }
+        public bool IsInvisible { get; set; }
+        public bool IsNotDisturb { get; set; }
+        [MaxLength(1024)] public string? Label { get; set; }
+        public Instant? ClearedAt { get; set; }
+    }
+
+    [HttpGet("{name}/statuses")]
+    public async Task<ActionResult<Status>> GetOtherStatus(string name)
+    {
+        var account = await db.Accounts.FirstOrDefaultAsync(a => a.Name == name);
+        if (account is null) return BadRequest();
+        var status = await events.GetStatus(account.Id);
+        status.IsInvisible = false; // Keep the invisible field not available for other users
+        return Ok(status);
+    }
+
+    [HttpGet("{name}/calendar")]
+    public async Task<ActionResult<List<DailyEventResponse>>> GetOtherEventCalendar(
+        string name,
+        [FromQuery] int? month,
+        [FromQuery] int? year
+    )
+    {
+        var currentDate = SystemClock.Instance.GetCurrentInstant().InUtc().Date;
+        month ??= currentDate.Month;
+        year ??= currentDate.Year;
+
+        if (month is < 1 or > 12) return BadRequest("Invalid month.");
+        if (year < 1) return BadRequest("Invalid year.");
+
+        var account = await db.Accounts.FirstOrDefaultAsync(a => a.Name == name);
+        if (account is null) return BadRequest();
+
+        var calendar = await events.GetEventCalendar(account, month.Value, year.Value, replaceInvisible: true);
+        return Ok(calendar);
+    }
+
+    [HttpGet("search")]
+    public async Task<List<Common.Models.Account>> Search([FromQuery] string query, [FromQuery] int take = 20)
+    {
+        if (string.IsNullOrWhiteSpace(query))
+            return [];
+        return await db.Accounts
+            .Include(e => e.Profile)
+            .Where(a => EF.Functions.ILike(a.Name, $"%{query}%") ||
+                        EF.Functions.ILike(a.Nick, $"%{query}%"))
+            .Take(take)
+            .ToListAsync();
+    }
+}

DysonNetwork.Pass/Features/Account/Controllers/AccountCurrentController.cs

@@ -0,0 +1,703 @@
+using System.ComponentModel.DataAnnotations;
+using DysonNetwork.Common.Models;
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Pass.Features.Account.Services;
+using DysonNetwork.Pass.Features.Auth;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Account.Controllers;
+
+[Authorize]
+[ApiController]
+[Route("/accounts/me")]
+public class AccountCurrentController(
+    PassDatabase db,
+    AccountService accounts,
+    FileReferenceService fileRefService,
+    AccountEventService events,
+    AuthService auth
+) : ControllerBase
+{
+    [HttpGet]
+    [ProducesResponseType<Common.Models.Account>(StatusCodes.Status200OK)]
+    public async Task<ActionResult<Common.Models.Account>> GetCurrentIdentity()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+        var userId = currentUser.Id;
+
+        var account = await db.Accounts
+            .Include(e => e.Badges)
+            .Include(e => e.Profile)
+            .Where(e => e.Id == userId)
+            .FirstOrDefaultAsync();
+
+        return Ok(account);
+    }
+
+    public class BasicInfoRequest
+    {
+        [MaxLength(256)] public string? Nick { get; set; }
+        [MaxLength(32)] public string? Language { get; set; }
+    }
+
+    [HttpPatch]
+    public async Task<ActionResult<Account>> UpdateBasicInfo([FromBody] BasicInfoRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var account = await db.Accounts.FirstAsync(a => a.Id == currentUser.Id);
+
+        if (request.Nick is not null) account.Nick = request.Nick;
+        if (request.Language is not null) account.Language = request.Language;
+
+        await db.SaveChangesAsync();
+        await accounts.PurgeAccountCache(currentUser);
+        return currentUser;
+    }
+
+    public class ProfileRequest
+    {
+        [MaxLength(256)] public string? FirstName { get; set; }
+        [MaxLength(256)] public string? MiddleName { get; set; }
+        [MaxLength(256)] public string? LastName { get; set; }
+        [MaxLength(1024)] public string? Gender { get; set; }
+        [MaxLength(1024)] public string? Pronouns { get; set; }
+        [MaxLength(1024)] public string? TimeZone { get; set; }
+        [MaxLength(1024)] public string? Location { get; set; }
+        [MaxLength(4096)] public string? Bio { get; set; }
+        public Instant? Birthday { get; set; }
+
+        [MaxLength(32)] public string? PictureId { get; set; }
+        [MaxLength(32)] public string? BackgroundId { get; set; }
+    }
+
+    [HttpPatch("profile")]
+    public async Task<ActionResult<Profile>> UpdateProfile([FromBody] ProfileRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+        var userId = currentUser.Id;
+
+        var profile = await db.AccountProfiles
+            .Where(p => p.Account.Id == userId)
+            .FirstOrDefaultAsync();
+        if (profile is null) return BadRequest("Unable to get your account.");
+
+        if (request.FirstName is not null) profile.FirstName = request.FirstName;
+        if (request.MiddleName is not null) profile.MiddleName = request.MiddleName;
+        if (request.LastName is not null) profile.LastName = request.LastName;
+        if (request.Bio is not null) profile.Bio = request.Bio;
+        if (request.Gender is not null) profile.Gender = request.Gender;
+        if (request.Pronouns is not null) profile.Pronouns = request.Pronouns;
+        if (request.Birthday is not null) profile.Birthday = request.Birthday;
+        if (request.Location is not null) profile.Location = request.Location;
+        if (request.TimeZone is not null) profile.TimeZone = request.TimeZone;
+
+        if (request.PictureId is not null)
+        {
+            var picture = await db.Files.Where(f => f.Id == request.PictureId).FirstOrDefaultAsync();
+            if (picture is null) return BadRequest("Invalid picture id, unable to find the file on cloud.");
+
+            var profileResourceId = $"profile:{profile.Id}";
+
+            // Remove old references for the profile picture
+            if (profile.Picture is not null)
+            {
+                var oldPictureRefs =
+                    await fileRefService.GetResourceReferencesAsync(profileResourceId, "profile.picture");
+                foreach (var oldRef in oldPictureRefs)
+                {
+                    await fileRefService.DeleteReferenceAsync(oldRef.Id);
+                }
+            }
+
+            profile.Picture = picture.ToReferenceObject();
+
+            // Create new reference
+            await fileRefService.CreateReferenceAsync(
+                picture.Id,
+                "profile.picture",
+                profileResourceId
+            );
+        }
+
+        if (request.BackgroundId is not null)
+        {
+            var background = await db.Files.Where(f => f.Id == request.BackgroundId).FirstOrDefaultAsync();
+            if (background is null) return BadRequest("Invalid background id, unable to find the file on cloud.");
+
+            var profileResourceId = $"profile:{profile.Id}";
+
+            // Remove old references for the profile background
+            if (profile.Background is not null)
+            {
+                var oldBackgroundRefs =
+                    await fileRefService.GetResourceReferencesAsync(profileResourceId, "profile.background");
+                foreach (var oldRef in oldBackgroundRefs)
+                {
+                    await fileRefService.DeleteReferenceAsync(oldRef.Id);
+                }
+            }
+
+            profile.Background = background.ToReferenceObject();
+
+            // Create new reference
+            await fileRefService.CreateReferenceAsync(
+                background.Id,
+                "profile.background",
+                profileResourceId
+            );
+        }
+
+        db.Update(profile);
+        await db.SaveChangesAsync();
+
+        await accounts.PurgeAccountCache(currentUser);
+
+        return profile;
+    }
+
+    [HttpDelete]
+    public async Task<ActionResult> RequestDeleteAccount()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        try
+        {
+            await accounts.RequestAccountDeletion(currentUser);
+        }
+        catch (InvalidOperationException)
+        {
+            return BadRequest("You already requested account deletion within 24 hours.");
+        }
+
+        return Ok();
+    }
+
+    [HttpGet("statuses")]
+    public async Task<ActionResult<Status>> GetCurrentStatus()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+        var status = await events.GetStatus(currentUser.Id);
+        return Ok(status);
+    }
+
+    [HttpPatch("statuses")]
+    [RequiredPermission("global", "accounts.statuses.update")]
+    public async Task<ActionResult<Status>> UpdateStatus([FromBody] AccountController.StatusRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var now = SystemClock.Instance.GetCurrentInstant();
+        var status = await db.AccountStatuses
+            .Where(e => e.AccountId == currentUser.Id)
+            .Where(e => e.ClearedAt == null || e.ClearedAt > now)
+            .OrderByDescending(e => e.CreatedAt)
+            .FirstOrDefaultAsync();
+        if (status is null) return NotFound();
+
+        status.Attitude = request.Attitude;
+        status.IsInvisible = request.IsInvisible;
+        status.IsNotDisturb = request.IsNotDisturb;
+        status.Label = request.Label;
+        status.ClearedAt = request.ClearedAt;
+
+        db.Update(status);
+        await db.SaveChangesAsync();
+        events.PurgeStatusCache(currentUser.Id);
+
+        return status;
+    }
+
+    [HttpPost("statuses")]
+    [RequiredPermission("global", "accounts.statuses.create")]
+    public async Task<ActionResult<Status>> CreateStatus([FromBody] AccountController.StatusRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var status = new Status
+        {
+            AccountId = currentUser.Id,
+            Attitude = request.Attitude,
+            IsInvisible = request.IsInvisible,
+            IsNotDisturb = request.IsNotDisturb,
+            Label = request.Label,
+            ClearedAt = request.ClearedAt
+        };
+
+        return await events.CreateStatus(currentUser, status);
+    }
+
+    [HttpDelete("me/statuses")]
+    public async Task<ActionResult> DeleteStatus()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var now = SystemClock.Instance.GetCurrentInstant();
+        var status = await db.AccountStatuses
+            .Where(s => s.AccountId == currentUser.Id)
+            .Where(s => s.ClearedAt == null || s.ClearedAt > now)
+            .OrderByDescending(s => s.CreatedAt)
+            .FirstOrDefaultAsync();
+        if (status is null) return NotFound();
+
+        await events.ClearStatus(currentUser, status);
+        return NoContent();
+    }
+
+    [HttpGet("check-in")]
+    public async Task<ActionResult<CheckInResult>> GetCheckInResult()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+        var userId = currentUser.Id;
+
+        var now = SystemClock.Instance.GetCurrentInstant();
+        var today = now.InUtc().Date;
+        var startOfDay = today.AtStartOfDayInZone(DateTimeZone.Utc).ToInstant();
+        var endOfDay = today.PlusDays(1).AtStartOfDayInZone(DateTimeZone.Utc).ToInstant();
+
+        var result = await db.AccountCheckInResults
+            .Where(x => x.AccountId == userId)
+            .Where(x => x.CreatedAt >= startOfDay && x.CreatedAt < endOfDay)
+            .OrderByDescending(x => x.CreatedAt)
+            .FirstOrDefaultAsync();
+
+        return result is null ? NotFound() : Ok(result);
+    }
+
+    [HttpPost("check-in")]
+    public async Task<ActionResult<CheckInResult>> DoCheckIn([FromBody] string? captchaToken)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var isAvailable = await events.CheckInDailyIsAvailable(currentUser);
+        if (!isAvailable)
+            return BadRequest("Check-in is not available for today.");
+
+        try
+        {
+            var needsCaptcha = await events.CheckInDailyDoAskCaptcha(currentUser);
+            return needsCaptcha switch
+            {
+                true when string.IsNullOrWhiteSpace(captchaToken) => StatusCode(423,
+                    "Captcha is required for this check-in."),
+                true when !await auth.ValidateCaptcha(captchaToken!) => BadRequest("Invalid captcha token."),
+                _ => await events.CheckInDaily(currentUser)
+            };
+        }
+        catch (InvalidOperationException ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpGet("calendar")]
+    public async Task<ActionResult<List<DailyEventResponse>>> GetEventCalendar([FromQuery] int? month,
+        [FromQuery] int? year)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var currentDate = SystemClock.Instance.GetCurrentInstant().InUtc().Date;
+        month ??= currentDate.Month;
+        year ??= currentDate.Year;
+
+        if (month is < 1 or > 12) return BadRequest("Invalid month.");
+        if (year < 1) return BadRequest("Invalid year.");
+
+        var calendar = await events.GetEventCalendar(currentUser, month.Value, year.Value);
+        return Ok(calendar);
+    }
+
+    [HttpGet("actions")]
+    [ProducesResponseType<List<ActionLog>>(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
+    public async Task<ActionResult<List<ActionLog>>> GetActionLogs(
+        [FromQuery] int take = 20,
+        [FromQuery] int offset = 0
+    )
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var query = db.ActionLogs
+            .Where(log => log.AccountId == currentUser.Id)
+            .OrderByDescending(log => log.CreatedAt);
+
+        var total = await query.CountAsync();
+        Response.Headers.Append("X-Total", total.ToString());
+
+        var logs = await query
+            .Skip(offset)
+            .Take(take)
+            .ToListAsync();
+
+        return Ok(logs);
+    }
+
+    [HttpGet("factors")]
+    public async Task<ActionResult<List<AccountAuthFactor>>> GetAuthFactors()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var factors = await db.AccountAuthFactors
+            .Include(f => f.Account)
+            .Where(f => f.Account.Id == currentUser.Id)
+            .ToListAsync();
+
+        return Ok(factors);
+    }
+
+    public class AuthFactorRequest
+    {
+        public AccountAuthFactorType Type { get; set; }
+        public string? Secret { get; set; }
+    }
+
+    [HttpPost("factors")]
+    [Authorize]
+    public async Task<ActionResult<AccountAuthFactor>> CreateAuthFactor([FromBody] AuthFactorRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+        if (await accounts.CheckAuthFactorExists(currentUser, request.Type))
+            return BadRequest($"Auth factor with type {request.Type} is already exists.");
+
+        var factor = await accounts.CreateAuthFactor(currentUser, request.Type, request.Secret);
+        return Ok(factor);
+    }
+
+    [HttpPost("factors/{id:guid}/enable")]
+    [Authorize]
+    public async Task<ActionResult<AccountAuthFactor>> EnableAuthFactor(Guid id, [FromBody] string? code)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var factor = await db.AccountAuthFactors
+            .Where(f => f.AccountId == currentUser.Id && f.Id == id)
+            .FirstOrDefaultAsync();
+        if (factor is null) return NotFound();
+
+        try
+        {
+            factor = await accounts.EnableAuthFactor(factor, code);
+            return Ok(factor);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpPost("factors/{id:guid}/disable")]
+    [Authorize]
+    public async Task<ActionResult<AccountAuthFactor>> DisableAuthFactor(Guid id)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var factor = await db.AccountAuthFactors
+            .Where(f => f.AccountId == currentUser.Id && f.Id == id)
+            .FirstOrDefaultAsync();
+        if (factor is null) return NotFound();
+
+        try
+        {
+            factor = await accounts.DisableAuthFactor(factor);
+            return Ok(factor);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpDelete("factors/{id:guid}")]
+    [Authorize]
+    public async Task<ActionResult<AccountAuthFactor>> DeleteAuthFactor(Guid id)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var factor = await db.AccountAuthFactors
+            .Where(f => f.AccountId == currentUser.Id && f.Id == id)
+            .FirstOrDefaultAsync();
+        if (factor is null) return NotFound();
+
+        try
+        {
+            await accounts.DeleteAuthFactor(factor);
+            return NoContent();
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    public class AuthorizedDevice
+    {
+        public string? Label { get; set; }
+        public string UserAgent { get; set; } = null!;
+        public string DeviceId { get; set; } = null!;
+        public ChallengePlatform Platform { get; set; }
+        public List<Session> Sessions { get; set; } = [];
+    }
+
+    [HttpGet("devices")]
+    [Authorize]
+    public async Task<ActionResult<List<AuthorizedDevice>>> GetDevices()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser ||
+            HttpContext.Items["CurrentSession"] is not Session currentSession) return Unauthorized();
+
+        Response.Headers.Append("X-Auth-Session", currentSession.Id.ToString());
+
+        // Group sessions by the related DeviceId, then create an AuthorizedDevice for each group.
+        var deviceGroups = await db.AuthSessions
+            .Where(s => s.Account.Id == currentUser.Id)
+            .Include(s => s.Challenge)
+            .GroupBy(s => s.Challenge.DeviceId!)
+            .Select(g => new AuthorizedDevice
+            {
+                DeviceId = g.Key!,
+                UserAgent = g.First(x => x.Challenge.UserAgent != null).Challenge.UserAgent!,
+                Platform = g.First().Challenge.Platform!,
+                Label = g.Where(x => !string.IsNullOrWhiteSpace(x.Label)).Select(x => x.Label).FirstOrDefault(),
+                Sessions = g
+                    .OrderByDescending(x => x.LastGrantedAt)
+                    .ToList()
+            })
+            .ToListAsync();
+        deviceGroups = deviceGroups
+            .OrderByDescending(s => s.Sessions.First().LastGrantedAt)
+            .ToList();
+
+        return Ok(deviceGroups);
+    }
+
+    [HttpGet("sessions")]
+    [Authorize]
+    public async Task<ActionResult<List<Session>>> GetSessions(
+        [FromQuery] int take = 20,
+        [FromQuery] int offset = 0
+    )
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser ||
+            HttpContext.Items["CurrentSession"] is not Session currentSession) return Unauthorized();
+
+        var query = db.AuthSessions
+            .Include(session => session.Account)
+            .Include(session => session.Challenge)
+            .Where(session => session.Account.Id == currentUser.Id);
+
+        var total = await query.CountAsync();
+        Response.Headers.Append("X-Total", total.ToString());
+        Response.Headers.Append("X-Auth-Session", currentSession.Id.ToString());
+
+        var sessions = await query
+            .OrderByDescending(x => x.LastGrantedAt)
+            .Skip(offset)
+            .Take(take)
+            .ToListAsync();
+
+        return Ok(sessions);
+    }
+
+    [HttpDelete("sessions/{id:guid}")]
+    [Authorize]
+    public async Task<ActionResult<Session>> DeleteSession(Guid id)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        try
+        {
+            await accounts.DeleteSession(currentUser, id);
+            return NoContent();
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpDelete("sessions/current")]
+    [Authorize]
+    public async Task<ActionResult<Session>> DeleteCurrentSession()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser ||
+            HttpContext.Items["CurrentSession"] is not Session currentSession) return Unauthorized();
+
+        try
+        {
+            await accounts.DeleteSession(currentUser, currentSession.Id);
+            return NoContent();
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpPatch("sessions/{id:guid}/label")]
+    public async Task<ActionResult<Session>> UpdateSessionLabel(Guid id, [FromBody] string label)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        try
+        {
+            await accounts.UpdateSessionLabel(currentUser, id, label);
+            return NoContent();
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpPatch("sessions/current/label")]
+    public async Task<ActionResult<Session>> UpdateCurrentSessionLabel([FromBody] string label)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser ||
+            HttpContext.Items["CurrentSession"] is not Session currentSession) return Unauthorized();
+
+        try
+        {
+            await accounts.UpdateSessionLabel(currentUser, currentSession.Id, label);
+            return NoContent();
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpGet("contacts")]
+    [Authorize]
+    public async Task<ActionResult<List<AccountContact>>> GetContacts()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var contacts = await db.AccountContacts
+            .Where(c => c.AccountId == currentUser.Id)
+            .ToListAsync();
+
+        return Ok(contacts);
+    }
+
+    public class AccountContactRequest
+    {
+        [Required] public AccountContactType Type { get; set; }
+        [Required] public string Content { get; set; } = null!;
+    }
+
+    [HttpPost("contacts")]
+    [Authorize]
+    public async Task<ActionResult<AccountContact>> CreateContact([FromBody] AccountContactRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        try
+        {
+            var contact = await accounts.CreateContactMethod(currentUser, request.Type, request.Content);
+            return Ok(contact);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpPost("contacts/{id:guid}/verify")]
+    [Authorize]
+    public async Task<ActionResult<AccountContact>> VerifyContact(Guid id)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var contact = await db.AccountContacts
+            .Where(c => c.AccountId == currentUser.Id && c.Id == id)
+            .FirstOrDefaultAsync();
+        if (contact is null) return NotFound();
+
+        try
+        {
+            await accounts.VerifyContactMethod(currentUser, contact);
+            return Ok(contact);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpPost("contacts/{id:guid}/primary")]
+    [Authorize]
+    public async Task<ActionResult<AccountContact>> SetPrimaryContact(Guid id)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var contact = await db.AccountContacts
+            .Where(c => c.AccountId == currentUser.Id && c.Id == id)
+            .FirstOrDefaultAsync();
+        if (contact is null) return NotFound();
+
+        try
+        {
+            contact = await accounts.SetContactMethodPrimary(currentUser, contact);
+            return Ok(contact);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpDelete("contacts/{id:guid}")]
+    [Authorize]
+    public async Task<ActionResult<AccountContact>> DeleteContact(Guid id)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var contact = await db.AccountContacts
+            .Where(c => c.AccountId == currentUser.Id && c.Id == id)
+            .FirstOrDefaultAsync();
+        if (contact is null) return NotFound();
+
+        try
+        {
+            await accounts.DeleteContactMethod(currentUser, contact);
+            return NoContent();
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+
+    [HttpGet("badges")]
+    [ProducesResponseType<List<Badge>>(StatusCodes.Status200OK)]
+    [Authorize]
+    public async Task<ActionResult<List<Badge>>> GetBadges()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        var badges = await db.Badges
+            .Where(b => b.AccountId == currentUser.Id)
+            .ToListAsync();
+        return Ok(badges);
+    }
+
+    [HttpPost("badges/{id:guid}/active")]
+    [Authorize]
+    public async Task<ActionResult<Badge>> ActivateBadge(Guid id)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Account currentUser) return Unauthorized();
+
+        try
+        {
+            await accounts.ActiveBadge(currentUser, id);
+            return Ok();
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+}

DysonNetwork.Pass/Features/Account/Controllers/MagicSpellController.cs

@@ -0,0 +1,21 @@
+using Microsoft.AspNetCore.Mvc;
+
+using DysonNetwork.Pass.Data;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+[ApiController]
+[Route("/spells")]
+public class MagicSpellController(PassDatabase db, MagicSpellService sp) : ControllerBase
+{
+    [HttpPost("{spellId:guid}/resend")]
+    public async Task<ActionResult> ResendMagicSpell(Guid spellId)
+    {
+        var spell = db.MagicSpells.FirstOrDefault(x => x.Id == spellId);
+        if (spell == null)
+            return NotFound();
+    
+        await sp.NotifyMagicSpell(spell, true);
+        return Ok();
+    }
+}

DysonNetwork.Pass/Features/Account/Controllers/NotificationController.cs

@@ -0,0 +1,166 @@
+using System.ComponentModel.DataAnnotations;
+using DysonNetwork.Pass.Features.Auth;
+using DysonNetwork.Common.Models;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+[ApiController]
+[Route("/notifications")]
+public class NotificationController(PassDatabase db, NotificationService nty) : ControllerBase
+{
+    [HttpGet("count")]
+    [Authorize]
+    public async Task<ActionResult<int>> CountUnreadNotifications()
+    {
+        HttpContext.Items.TryGetValue("CurrentUser", out var currentUserValue);
+        if (currentUserValue is not Common.Models.Account currentUser) return Unauthorized();
+
+        var count = await db.Notifications
+            .Where(s => s.AccountId == currentUser.Id && s.ViewedAt == null)
+            .CountAsync();
+        return Ok(count);
+    }
+
+    [HttpGet]
+    [Authorize]
+    public async Task<ActionResult<List<Notification>>> ListNotifications(
+        [FromQuery] int offset = 0,
+        // The page size set to 5 is to avoid the client pulled the notification
+        // but didn't render it in the screen-viewable region.
+        [FromQuery] int take = 5
+    )
+    {
+        HttpContext.Items.TryGetValue("CurrentUser", out var currentUserValue);
+        if (currentUserValue is not Common.Models.Account currentUser) return Unauthorized();
+
+        var totalCount = await db.Notifications
+            .Where(s => s.AccountId == currentUser.Id)
+            .CountAsync();
+        var notifications = await db.Notifications
+            .Where(s => s.AccountId == currentUser.Id)
+            .OrderByDescending(e => e.CreatedAt)
+            .Skip(offset)
+            .Take(take)
+            .ToListAsync();
+
+        Response.Headers["X-Total"] = totalCount.ToString();
+        await nty.MarkNotificationsViewed(notifications);
+
+        return Ok(notifications);
+    }
+
+    public class PushNotificationSubscribeRequest
+    {
+        [MaxLength(4096)] public string DeviceToken { get; set; } = null!;
+        public NotificationPushProvider Provider { get; set; }
+    }
+
+    [HttpPut("subscription")]
+    [Authorize]
+    public async Task<ActionResult<NotificationPushSubscription>> SubscribeToPushNotification(
+        [FromBody] PushNotificationSubscribeRequest request
+    )
+    {
+        HttpContext.Items.TryGetValue("CurrentSession", out var currentSessionValue);
+        HttpContext.Items.TryGetValue("CurrentUser", out var currentUserValue);
+        var currentUser = currentUserValue as Common.Models.Account;
+        if (currentUser == null) return Unauthorized();
+        var currentSession = currentSessionValue as Session;
+        if (currentSession == null) return Unauthorized();
+
+        var result =
+            await nty.SubscribePushNotification(currentUser, request.Provider, currentSession.Challenge.DeviceId!,
+                request.DeviceToken);
+
+        return Ok(result);
+    }
+
+    [HttpDelete("subscription")]
+    [Authorize]
+    public async Task<ActionResult<int>> UnsubscribeFromPushNotification()
+    {
+        HttpContext.Items.TryGetValue("CurrentSession", out var currentSessionValue);
+        HttpContext.Items.TryGetValue("CurrentUser", out var currentUserValue);
+        var currentUser = currentUserValue as Common.Models.Account;
+        if (currentUser == null) return Unauthorized();
+        var currentSession = currentSessionValue as Session;
+        if (currentSession == null) return Unauthorized();
+
+        var affectedRows = await db.NotificationPushSubscriptions
+            .Where(s =>
+                s.AccountId == currentUser.Id &&
+                s.DeviceId == currentSession.Challenge.DeviceId
+            ).ExecuteDeleteAsync();
+        return Ok(affectedRows);
+    }
+
+    public class NotificationRequest
+    {
+        [Required] [MaxLength(1024)] public string Topic { get; set; } = null!;
+        [Required] [MaxLength(1024)] public string Title { get; set; } = null!;
+        [MaxLength(2048)] public string? Subtitle { get; set; }
+        [Required] [MaxLength(4096)] public string Content { get; set; } = null!;
+        public Dictionary<string, object>? Meta { get; set; }
+        public int Priority { get; set; } = 10;
+    }
+
+    [HttpPost("broadcast")]
+    [Authorize]
+    [RequiredPermission("global", "notifications.broadcast")]
+    public async Task<ActionResult> BroadcastNotification(
+        [FromBody] NotificationRequest request,
+        [FromQuery] bool save = false
+    )
+    {
+        await nty.BroadcastNotification(
+            new Notification
+            {
+                CreatedAt = SystemClock.Instance.GetCurrentInstant(),
+                UpdatedAt = SystemClock.Instance.GetCurrentInstant(),
+                Topic = request.Topic,
+                Title = request.Title,
+                Subtitle = request.Subtitle,
+                Content = request.Content,
+                Meta = request.Meta,
+                Priority = request.Priority,
+            },
+            save
+        );
+        return Ok();
+    }
+
+    public class NotificationWithAimRequest : NotificationRequest
+    {
+        [Required] public List<Guid> AccountId { get; set; } = null!;
+    }
+    
+    [HttpPost("send")]
+    [Authorize]
+    [RequiredPermission("global", "notifications.send")]
+    public async Task<ActionResult> SendNotification(
+        [FromBody] NotificationWithAimRequest request,
+        [FromQuery] bool save = false
+    )
+    {
+        var accounts = await db.Accounts.Where(a => request.AccountId.Contains(a.Id)).ToListAsync();
+        await nty.SendNotificationBatch(
+            new Notification
+            {
+                CreatedAt = SystemClock.Instance.GetCurrentInstant(),
+                UpdatedAt = SystemClock.Instance.GetCurrentInstant(),
+                Topic = request.Topic,
+                Title = request.Title,
+                Subtitle = request.Subtitle,
+                Content = request.Content,
+                Meta = request.Meta,
+            },
+            accounts,
+            save
+        );
+        return Ok();
+    }
+}

DysonNetwork.Pass/Features/Account/Controllers/RelationshipController.cs

@@ -0,0 +1,255 @@
+using System.ComponentModel.DataAnnotations;
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Common.Models;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+[ApiController]
+[Route("/relationships")]
+public class RelationshipController(PassDatabase db, RelationshipService rels) : ControllerBase
+{
+    [HttpGet]
+    [Authorize]
+    public async Task<ActionResult<List<Relationship>>> ListRelationships([FromQuery] int offset = 0,
+        [FromQuery] int take = 20)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+        var userId = currentUser.Id;
+
+        var query = db.AccountRelationships.AsQueryable()
+            .Where(r => r.RelatedId == userId);
+        var totalCount = await query.CountAsync();
+        var relationships = await query
+            .Include(r => r.Related)
+            .Include(r => r.Related.Profile)
+            .Include(r => r.Account)
+            .Include(r => r.Account.Profile)
+            .Skip(offset)
+            .Take(take)
+            .ToListAsync();
+
+        var statuses = await db.AccountRelationships
+            .Where(r => r.AccountId == userId)
+            .ToDictionaryAsync(r => r.RelatedId);
+        foreach (var relationship in relationships)
+            if (statuses.TryGetValue(relationship.RelatedId, out var status))
+                relationship.Status = status.Status;
+
+        Response.Headers["X-Total"] = totalCount.ToString();
+
+        return relationships;
+    }
+
+    [HttpGet("requests")]
+    [Authorize]
+    public async Task<ActionResult<List<Relationship>>> ListSentRequests()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        var relationships = await db.AccountRelationships
+            .Where(r => r.AccountId == currentUser.Id && r.Status == RelationshipStatus.Pending)
+            .Include(r => r.Related)
+            .Include(r => r.Related.Profile)
+            .Include(r => r.Account)
+            .Include(r => r.Account.Profile)
+            .ToListAsync();
+
+        return relationships;
+    }
+
+    public class RelationshipRequest
+    {
+        [Required] public RelationshipStatus Status { get; set; }
+    }
+
+    [HttpPost("{userId:guid}")]
+    [Authorize]
+    public async Task<ActionResult<Relationship>> CreateRelationship(Guid userId,
+        [FromBody] RelationshipRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        var relatedUser = await db.Accounts.FindAsync(userId);
+        if (relatedUser is null) return NotFound("Account was not found.");
+
+        try
+        {
+            var relationship = await rels.CreateRelationship(
+                currentUser, relatedUser, request.Status
+            );
+            return relationship;
+        }
+        catch (InvalidOperationException err)
+        {
+            return BadRequest(err.Message);
+        }
+    }
+
+    [HttpPatch("{userId:guid}")]
+    [Authorize]
+    public async Task<ActionResult<Relationship>> UpdateRelationship(Guid userId,
+        [FromBody] RelationshipRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        try
+        {
+            var relationship = await rels.UpdateRelationship(currentUser.Id, userId, request.Status);
+            return relationship;
+        }
+        catch (ArgumentException err)
+        {
+            return NotFound(err.Message);
+        }
+        catch (InvalidOperationException err)
+        {
+            return BadRequest(err.Message);
+        }
+    }
+
+    [HttpGet("{userId:guid}")]
+    [Authorize]
+    public async Task<ActionResult<Relationship>> GetRelationship(Guid userId)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        var now = Instant.FromDateTimeUtc(DateTime.UtcNow);
+        var queries = db.AccountRelationships.AsQueryable()
+            .Where(r => r.AccountId == currentUser.Id && r.RelatedId == userId)
+            .Where(r => r.ExpiredAt == null || r.ExpiredAt > now);
+        var relationship = await queries
+            .Include(r => r.Related)
+            .Include(r => r.Related.Profile)
+            .FirstOrDefaultAsync();
+        if (relationship is null) return NotFound();
+
+        relationship.Account = currentUser;
+        return Ok(relationship);
+    }
+
+    [HttpPost("{userId:guid}/friends")]
+    [Authorize]
+    public async Task<ActionResult<Relationship>> SendFriendRequest(Guid userId)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        var relatedUser = await db.Accounts.FindAsync(userId);
+        if (relatedUser is null) return NotFound("Account was not found.");
+
+        var existing = await db.AccountRelationships.FirstOrDefaultAsync(r =>
+            (r.AccountId == currentUser.Id && r.RelatedId == userId) ||
+            (r.AccountId == userId && r.RelatedId == currentUser.Id));
+        if (existing != null) return BadRequest("Relationship already exists.");
+
+        try
+        {
+            var relationship = await rels.SendFriendRequest(currentUser, relatedUser);
+            return relationship;
+        }
+        catch (InvalidOperationException err)
+        {
+            return BadRequest(err.Message);
+        }
+    }
+
+    [HttpDelete("{userId:guid}/friends")]
+    [Authorize]
+    public async Task<ActionResult> DeleteFriendRequest(Guid userId)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        try
+        {
+            await rels.DeleteFriendRequest(currentUser.Id, userId);
+            return NoContent();
+        }
+        catch (ArgumentException err)
+        {
+            return NotFound(err.Message);
+        }
+    }
+
+    [HttpPost("{userId:guid}/friends/accept")]
+    [Authorize]
+    public async Task<ActionResult<Relationship>> AcceptFriendRequest(Guid userId)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        var relationship = await rels.GetRelationship(userId, currentUser.Id, RelationshipStatus.Pending);
+        if (relationship is null) return NotFound("Friend request was not found.");
+
+        try
+        {
+            relationship = await rels.AcceptFriendRelationship(relationship);
+            return relationship;
+        }
+        catch (InvalidOperationException err)
+        {
+            return BadRequest(err.Message);
+        }
+    }
+
+    [HttpPost("{userId:guid}/friends/decline")]
+    [Authorize]
+    public async Task<ActionResult<Relationship>> DeclineFriendRequest(Guid userId)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        var relationship = await rels.GetRelationship(userId, currentUser.Id, RelationshipStatus.Pending);
+        if (relationship is null) return NotFound("Friend request was not found.");
+
+        try
+        {
+            relationship = await rels.AcceptFriendRelationship(relationship, status: RelationshipStatus.Blocked);
+            return relationship;
+        }
+        catch (InvalidOperationException err)
+        {
+            return BadRequest(err.Message);
+        }
+    }
+
+    [HttpPost("{userId:guid}/block")]
+    [Authorize]
+    public async Task<ActionResult<Relationship>> BlockUser(Guid userId)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        var relatedUser = await db.Accounts.FindAsync(userId);
+        if (relatedUser is null) return NotFound("Account was not found.");
+
+        try
+        {
+            var relationship = await rels.BlockAccount(currentUser, relatedUser);
+            return relationship;
+        }
+        catch (InvalidOperationException err)
+        {
+            return BadRequest(err.Message);
+        }
+    }
+    
+    [HttpDelete("{userId:guid}/block")]
+    [Authorize]
+    public async Task<ActionResult<Relationship>> UnblockUser(Guid userId)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Common.Models.Account currentUser) return Unauthorized();
+
+        var relatedUser = await db.Accounts.FindAsync(userId);
+        if (relatedUser is null) return NotFound("Account was not found.");
+
+        try
+        {
+            var relationship = await rels.UnblockAccount(currentUser, relatedUser);
+            return relationship;
+        }
+        catch (InvalidOperationException err)
+        {
+            return BadRequest(err.Message);
+        }
+    }
+}

DysonNetwork.Pass/Features/Account/Interfaces/IAccountEventService.cs

@@ -0,0 +1,20 @@
+using System.Globalization;
+using DysonNetwork.Common.Models;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Localization;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Account.Interfaces;
+
+public interface IAccountEventService
+{
+    void PurgeStatusCache(Guid userId);
+    Task<Status> GetStatus(Guid userId);
+    Task<Dictionary<Guid, Status>> GetStatuses(List<Guid> userIds);
+    Task<Status> CreateStatus(Models.Account user, Status status);
+    Task ClearStatus(Models.Account user, Status status);
+    Task<bool> CheckInDailyDoAskCaptcha(Models.Account user);
+    Task<bool> CheckInDailyIsAvailable(Models.Account user);
+    Task<CheckInResult> CheckInDaily(Models.Account user);
+    Task<List<DailyEventResponse>> GetEventCalendar(Models.Account user, int month, int year = 0, bool replaceInvisible = false);
+}

DysonNetwork.Pass/Features/Account/Interfaces/IAccountService.cs

@@ -0,0 +1,46 @@
+using System.Globalization;
+using NodaTime;
+using DysonNetwork.Pass.Features.Auth;
+using DysonNetwork.Pass.Features.Auth.OpenId;
+using DysonNetwork.Common.Models;
+
+namespace DysonNetwork.Pass.Features.Account.Interfaces;
+
+public interface IAccountService
+{
+    static void SetCultureInfo(Models.Account account) { }
+    static void SetCultureInfo(string? languageCode) { }
+    Task PurgeAccountCache(Models.Account account);
+    Task<Models.Account?> LookupAccount(string probe);
+    Task<Models.Account?> LookupAccountByConnection(string identifier, string provider);
+    Task<int?> GetAccountLevel(Guid accountId);
+    Task<Models.Account> CreateAccount(
+        string name,
+        string nick,
+        string email,
+        string? password,
+        string language = "en-US",
+        bool isEmailVerified = false,
+        bool isActivated = false
+    );
+    Task<Models.Account> CreateAccount(OidcUserInfo userInfo);
+    Task RequestAccountDeletion(Models.Account account);
+    Task RequestPasswordReset(Models.Account account);
+    Task<bool> CheckAuthFactorExists(Models.Account account, AccountAuthFactorType type);
+    Task<AccountAuthFactor?> CreateAuthFactor(Models.Account account, AccountAuthFactorType type, string? secret);
+    Task<AccountAuthFactor> EnableAuthFactor(AccountAuthFactor factor, string? code);
+    Task<AccountAuthFactor> DisableAuthFactor(AccountAuthFactor factor);
+    Task DeleteAuthFactor(AccountAuthFactor factor);
+    Task SendFactorCode(Models.Account account, AccountAuthFactor factor, string? hint = null);
+    Task<bool> VerifyFactorCode(AccountAuthFactor factor, string code);
+    Task<Session> UpdateSessionLabel(Models.Account account, Guid sessionId, string label);
+    Task DeleteSession(Models.Account account, Guid sessionId);
+    Task<AccountContact> CreateContactMethod(Models.Account account, AccountContactType type, string content);
+    Task VerifyContactMethod(Models.Account account, AccountContact contact);
+    Task<AccountContact> SetContactMethodPrimary(Models.Account account, AccountContact contact);
+    Task DeleteContactMethod(Models.Account account, AccountContact contact);
+    Task<Badge> GrantBadge(Models.Account account, Badge badge);
+    Task RevokeBadge(Models.Account account, Guid badgeId);
+    Task ActiveBadge(Models.Account account, Guid badgeId);
+    Task EnsureAccountProfileCreated();
+}

DysonNetwork.Pass/Features/Account/Interfaces/IAccountUsernameService.cs

@@ -0,0 +1,9 @@
+namespace DysonNetwork.Pass.Features.Account.Interfaces;
+
+public interface IAccountUsernameService
+{
+    Task<string> GenerateUniqueUsernameAsync(string baseName);
+    string SanitizeUsername(string username);
+    Task<bool> IsUsernameExistsAsync(string username);
+    Task<string> GenerateUsernameFromEmailAsync(string email);
+}

DysonNetwork.Pass/Features/Account/Interfaces/IActionLogService.cs

@@ -0,0 +1,9 @@
+using DysonNetwork.Pass.Connection;
+
+namespace DysonNetwork.Pass.Features.Account.Interfaces;
+
+public interface IActionLogService
+{
+    void CreateActionLog(Guid accountId, string action, Dictionary<string, object> meta);
+    void CreateActionLogFromRequest(string action, Dictionary<string, object> meta, HttpRequest request, Models.Account? account = null);
+}

DysonNetwork.Pass/Features/Account/Interfaces/IMagicSpellService.cs

@@ -0,0 +1,20 @@
+using NodaTime;
+using DysonNetwork.Pass.Features.Account;
+using DysonNetwork.Common.Models;
+
+namespace DysonNetwork.Pass.Features.Account.Interfaces;
+
+public interface IMagicSpellService
+{
+    Task<MagicSpell> CreateMagicSpell(
+        Models.Account account,
+        MagicSpellType type,
+        Dictionary<string, object> meta,
+        Instant? expiredAt = null,
+        Instant? affectedAt = null,
+        bool preventRepeat = false
+    );
+    Task NotifyMagicSpell(MagicSpell spell, bool bypassVerify = false);
+    Task ApplyMagicSpell(MagicSpell spell);
+    Task ApplyPasswordReset(MagicSpell spell, string newPassword);
+}

DysonNetwork.Pass/Features/Account/Interfaces/INotificationService.cs

@@ -0,0 +1,31 @@
+using System.Collections.Generic;
+using DysonNetwork.Common.Models;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Account.Interfaces;
+
+public interface INotificationService
+{
+    Task UnsubscribePushNotifications(string deviceId);
+    Task<NotificationPushSubscription> SubscribePushNotification(
+        Models.Account account,
+        NotificationPushProvider provider,
+        string deviceId,
+        string deviceToken
+    );
+    Task<Notification> SendNotification(
+        Models.Account account,
+        string topic,
+        string? title = null,
+        string? subtitle = null,
+        string? content = null,
+        Dictionary<string, object>? meta = null,
+        string? actionUri = null,
+        bool isSilent = false,
+        bool save = true
+    );
+    Task DeliveryNotification(Notification notification);
+    Task MarkNotificationsViewed(ICollection<Notification> notifications);
+    Task BroadcastNotification(Notification notification, bool save = false);
+    Task SendNotificationBatch(Notification notification, List<Models.Account> accounts, bool save = false);
+}

DysonNetwork.Pass/Features/Account/Interfaces/IRelationshipService.cs

@@ -0,0 +1,28 @@
+using DysonNetwork.Common.Models;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Account.Interfaces;
+
+public interface IRelationshipService
+{
+    Task<bool> HasExistingRelationship(Guid accountId, Guid relatedId);
+    Task<Relationship?> GetRelationship(
+        Guid accountId,
+        Guid relatedId,
+        RelationshipStatus? status = null,
+        bool ignoreExpired = false
+    );
+    Task<Relationship> CreateRelationship(Models.Account sender, Models.Account target, RelationshipStatus status);
+    Task<Relationship> BlockAccount(Models.Account sender, Models.Account target);
+    Task<Relationship> UnblockAccount(Models.Account sender, Models.Account target);
+    Task<Relationship> SendFriendRequest(Models.Account sender, Models.Account target);
+    Task DeleteFriendRequest(Guid accountId, Guid relatedId);
+    Task<Relationship> AcceptFriendRelationship(
+        Relationship relationship,
+        RelationshipStatus status = RelationshipStatus.Friends
+    );
+    Task<Relationship> UpdateRelationship(Guid accountId, Guid relatedId, RelationshipStatus status);
+    Task<List<Guid>> ListAccountFriends(Models.Account account);
+    Task<List<Guid>> ListAccountBlocked(Models.Account account);
+    Task<bool> HasRelationshipWithStatus(Guid accountId, Guid relatedId, RelationshipStatus status = RelationshipStatus.Friends);
+}

DysonNetwork.Pass/Features/Account/Services/AccountEventService.cs

@@ -0,0 +1,345 @@
+using System.Globalization;
+using DysonNetwork.Common.Models;
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Pass.Storage;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Localization;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Account.Services;
+
+public class AccountEventService
+{
+    private readonly PassDatabase db;
+    private readonly ICacheService cache;
+    private readonly IStringLocalizer<Localization.AccountEventResource> localizer;
+
+    public AccountEventService(
+        PassDatabase db,
+        ICacheService cache,
+        IStringLocalizer<Localization.AccountEventResource> localizer
+    )
+    {
+        this.db = db;
+        this.cache = cache;
+        this.localizer = localizer;
+    }
+
+    private static readonly Random Random = new();
+    private const string StatusCacheKey = "AccountStatus_";
+
+    public void PurgeStatusCache(Guid userId)
+    {
+        var cacheKey = $"{StatusCacheKey}{userId}";
+        cache.RemoveAsync(cacheKey);
+    }
+
+    public async Task<Status> GetStatus(Guid userId)
+    {
+        var cacheKey = $"{StatusCacheKey}{userId}";
+        var cachedStatus = await cache.GetAsync<Status>(cacheKey);
+        if (cachedStatus is not null)
+        {
+            cachedStatus!.IsOnline = !cachedStatus.IsInvisible && ws.GetAccountIsConnected(userId);
+            return cachedStatus;
+        }
+
+        var now = SystemClock.Instance.GetCurrentInstant();
+        var status = await db.AccountStatuses
+            .Where(e => e.AccountId == userId)
+            .Where(e => e.ClearedAt == null || e.ClearedAt > now)
+            .OrderByDescending(e => e.CreatedAt)
+            .FirstOrDefaultAsync();
+        var isOnline = ws.GetAccountIsConnected(userId);
+        if (status is not null)
+        {
+            status.IsOnline = !status.IsInvisible && isOnline;
+            await cache.SetWithGroupsAsync(cacheKey, status, [$"{AccountService.AccountCachePrefix}{status.AccountId}"],
+                TimeSpan.FromMinutes(5));
+            return status;
+        }
+
+        if (isOnline)
+        {
+            return new Status
+            {
+                Attitude = StatusAttitude.Neutral,
+                IsOnline = true,
+                IsCustomized = false,
+                Label = "Online",
+                AccountId = userId,
+            };
+        }
+
+                return new Status
+        {
+            Attitude = StatusAttitude.Neutral,
+            IsOnline = false,
+            IsCustomized = false,
+            Label = "Offline",
+            AccountId = userId,
+        };
+    }
+
+    public async Task<Dictionary<Guid, Status>> GetStatuses(List<Guid> userIds)
+    {
+        var results = new Dictionary<Guid, Status>();
+        var cacheMissUserIds = new List<Guid>();
+
+        foreach (var userId in userIds)
+        {
+            var cacheKey = $"{StatusCacheKey}{userId}";
+            var cachedStatus = await cache.GetAsync<Status>(cacheKey);
+            if (cachedStatus != null)
+            {
+                cachedStatus.IsOnline = !cachedStatus.IsInvisible && ws.GetAccountIsConnected(userId);
+                results[userId] = cachedStatus;
+            }
+            else
+            {
+                cacheMissUserIds.Add(userId);
+            }
+        }
+
+        if (cacheMissUserIds.Any())
+        {
+            var now = SystemClock.Instance.GetCurrentInstant();
+            var statusesFromDb = await db.AccountStatuses
+                .Where(e => cacheMissUserIds.Contains(e.AccountId))
+                .Where(e => e.ClearedAt == null || e.ClearedAt > now)
+                .GroupBy(e => e.AccountId)
+                .Select(g => g.OrderByDescending(e => e.CreatedAt).First())
+                .ToListAsync();
+
+            var foundUserIds = new HashSet<Guid>();
+
+            foreach (var status in statusesFromDb)
+            {
+                var isOnline = ws.GetAccountIsConnected(status.AccountId);
+                status.IsOnline = !status.IsInvisible && isOnline;
+                results[status.AccountId] = status;
+                var cacheKey = $"{StatusCacheKey}{status.AccountId}";
+                await cache.SetAsync(cacheKey, status, TimeSpan.FromMinutes(5));
+                foundUserIds.Add(status.AccountId);
+            }
+
+            var usersWithoutStatus = cacheMissUserIds.Except(foundUserIds).ToList();
+            if (usersWithoutStatus.Any())
+            {
+                foreach (var userId in usersWithoutStatus)
+                {
+                    var isOnline = ws.GetAccountIsConnected(userId);
+                    var defaultStatus = new Status
+                    {
+                        Attitude = StatusAttitude.Neutral,
+                        IsOnline = isOnline,
+                        IsCustomized = false,
+                        Label = isOnline ? "Online" : "Offline",
+                        AccountId = userId,
+                    };
+                    results[userId] = defaultStatus;
+                }
+            }
+        }
+
+        return results;
+    }
+
+    public async Task<Status> CreateStatus(Common.Models.Account user, Status status)
+    {
+        var now = SystemClock.Instance.GetCurrentInstant();
+        await db.AccountStatuses
+            .Where(x => x.AccountId == user.Id && (x.ClearedAt == null || x.ClearedAt > now))
+            .ExecuteUpdateAsync(s => s.SetProperty(x => x.ClearedAt, now));
+
+        db.AccountStatuses.Add(status);
+        await db.SaveChangesAsync();
+
+        return status;
+    }
+
+    public async Task ClearStatus(Common.Models.Account user, Status status)
+    {
+        status.ClearedAt = SystemClock.Instance.GetCurrentInstant();
+        db.Update(status);
+        await db.SaveChangesAsync();
+        PurgeStatusCache(user.Id);
+    }
+
+    private const int FortuneTipCount = 7; // This will be the max index for each type (positive/negative)
+    private const string CaptchaCacheKey = "CheckInCaptcha_";
+    private const int CaptchaProbabilityPercent = 20;
+
+    public async Task<bool> CheckInDailyDoAskCaptcha(Common.Models.Account user)
+    {
+        var cacheKey = $"{CaptchaCacheKey}{user.Id}";
+        var needsCaptcha = await cache.GetAsync<bool?>(cacheKey);
+        if (needsCaptcha is not null)
+            return needsCaptcha!.Value;
+
+        var result = Random.Next(100) < CaptchaProbabilityPercent;
+        await cache.SetAsync(cacheKey, result, TimeSpan.FromHours(24));
+        return result;
+    }
+
+    public async Task<bool> CheckInDailyIsAvailable(Common.Models.Account user)
+    {
+        var now = SystemClock.Instance.GetCurrentInstant();
+        var lastCheckIn = await db.AccountCheckInResults
+            .Where(x => x.AccountId == user.Id)
+            .OrderByDescending(x => x.CreatedAt)
+            .FirstOrDefaultAsync();
+
+        if (lastCheckIn == null)
+            return true;
+
+        var lastDate = lastCheckIn.CreatedAt.InUtc().Date;
+        var currentDate = now.InUtc().Date;
+
+        return lastDate < currentDate;
+    }
+
+    public const string CheckInLockKey = "CheckInLock_";
+
+    public async Task<CheckInResult> CheckInDaily(Common.Models.Account user)
+    {
+        var lockKey = $"{CheckInLockKey}{user.Id}";
+        
+        try
+        {
+            var lk = await cache.AcquireLockAsync(lockKey, TimeSpan.FromMinutes(1), TimeSpan.FromMilliseconds(100));
+            
+            if (lk != null)
+                await lk.ReleaseAsync();
+        }
+        catch
+        {
+            // Ignore errors from this pre-check
+        }
+        
+        // Now try to acquire the lock properly
+        await using var lockObj = await cache.AcquireLockAsync(lockKey, TimeSpan.FromMinutes(1), TimeSpan.FromSeconds(5));
+        if (lockObj is null) throw new InvalidOperationException("Check-in was in progress.");
+
+        var cultureInfo = new CultureInfo(user.Language, false);
+        CultureInfo.CurrentCulture = cultureInfo;
+        CultureInfo.CurrentUICulture = cultureInfo;
+
+        // Generate 2 positive tips
+        var positiveIndices = Enumerable.Range(1, FortuneTipCount)
+            .OrderBy(_ => Random.Next())
+            .Take(2)
+            .ToList();
+        var tips = positiveIndices.Select(index => new FortuneTip
+        {
+            IsPositive = true, Title = localizer[$"FortuneTipPositiveTitle_{index}"].Value,
+            Content = localizer[$"FortuneTipPositiveContent_{index}"].Value
+        }).ToList();
+
+        // Generate 2 negative tips
+        var negativeIndices = Enumerable.Range(1, FortuneTipCount)
+            .Except(positiveIndices)
+            .OrderBy(_ => Random.Next())
+            .Take(2)
+            .ToList();
+        tips.AddRange(negativeIndices.Select(index => new FortuneTip
+        {
+            IsPositive = false, Title = localizer[$"FortuneTipNegativeTitle_{index}"].Value,
+            Content = localizer[$"FortuneTipNegativeContent_{index}"].Value
+        }));
+
+        var result = new CheckInResult
+        {
+            Tips = tips,
+            Level = (CheckInResultLevel)Random.Next(Enum.GetValues<CheckInResultLevel>().Length),
+            AccountId = user.Id,
+            RewardExperience = 100,
+            RewardPoints = 10,
+        };
+
+        var now = SystemClock.Instance.GetCurrentInstant().InUtc().Date;
+        try
+        {
+            if (result.RewardPoints.HasValue)
+                await payment.CreateTransactionWithAccountAsync(
+                    null,
+                    user.Id,
+                    WalletCurrency.SourcePoint,
+                    result.RewardPoints.Value,
+                    $"Check-in reward on {now:yyyy/MM/dd}"
+                );
+        }
+        catch
+        {
+            result.RewardPoints = null;
+        }
+
+        await db.AccountProfiles
+            .Where(p => p.AccountId == user.Id)
+            .ExecuteUpdateAsync(s =>
+                s.SetProperty(b => b.Experience, b => b.Experience + result.RewardExperience)
+            );
+        db.AccountCheckInResults.Add(result);
+        await db.SaveChangesAsync();  // Don't forget to save changes to the database
+
+        // The lock will be automatically released by the await using statement
+        return result;
+    }
+
+    public async Task<List<DailyEventResponse>> GetEventCalendar(Common.Models.Account user, int month, int year = 0,
+        bool replaceInvisible = false)
+    {
+        if (year == 0)
+            year = SystemClock.Instance.GetCurrentInstant().InUtc().Date.Year;
+
+        // Create start and end dates for the specified month
+        var startOfMonth = new LocalDate(year, month, 1).AtStartOfDayInZone(DateTimeZone.Utc).ToInstant();
+        var endOfMonth = startOfMonth.Plus(Duration.FromDays(DateTime.DaysInMonth(year, month)));
+
+        var statuses = await db.AccountStatuses
+            .AsNoTracking()
+            .TagWith("GetEventCalendar_Statuses")
+            .Where(x => x.AccountId == user.Id && x.CreatedAt >= startOfMonth && x.CreatedAt < endOfMonth)
+            .Select(x => new Status
+            {
+                Id = x.Id,
+                Attitude = x.Attitude,
+                IsInvisible = !replaceInvisible && x.IsInvisible,
+                IsNotDisturb = x.IsNotDisturb,
+                Label = x.Label,
+                ClearedAt = x.ClearedAt,
+                AccountId = x.AccountId,
+                CreatedAt = x.CreatedAt
+            })
+            .OrderBy(x => x.CreatedAt)
+            .ToListAsync();
+
+        var checkIn = await db.AccountCheckInResults
+            .AsNoTracking()
+            .TagWith("GetEventCalendar_CheckIn")
+            .Where(x => x.AccountId == user.Id && x.CreatedAt >= startOfMonth && x.CreatedAt < endOfMonth)
+            .ToListAsync();
+
+        var dates = Enumerable.Range(1, DateTime.DaysInMonth(year, month))
+            .Select(day => new LocalDate(year, month, day).AtStartOfDayInZone(DateTimeZone.Utc).ToInstant())
+            .ToList();
+
+        var statusesByDate = statuses
+            .GroupBy(s => s.CreatedAt.InUtc().Date)
+            .ToDictionary(g => g.Key, g => g.ToList());
+
+        var checkInByDate = checkIn
+            .ToDictionary(c => c.CreatedAt.InUtc().Date);
+
+        return dates.Select(date =>
+        {
+            var utcDate = date.InUtc().Date;
+            return new DailyEventResponse
+            {
+                Date = date,
+                CheckInResult = checkInByDate.GetValueOrDefault(utcDate),
+                Statuses = statusesByDate.GetValueOrDefault(utcDate, new List<Status>())
+            };
+        }).ToList();
+    }
+}

DysonNetwork.Pass/Features/Account/Services/AccountService.cs

@@ -0,0 +1,679 @@
+using System.Globalization;
+using DysonNetwork.Pass.Features.Auth;
+using DysonNetwork.Pass.Features.Auth.OpenId;
+using DysonNetwork.Pass.Email;
+using DysonNetwork.Pass.Localization;
+using DysonNetwork.Pass.Permission;
+using DysonNetwork.Pass.Storage;
+using EFCore.BulkExtensions;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Localization;
+using NodaTime;
+using OtpNet;
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Common.Models;
+using DysonNetwork.Pass.Features.Auth.Services;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+public class AccountService
+{
+    private readonly PassDatabase db;
+    private readonly MagicSpellService spells;
+    private readonly AccountUsernameService uname;
+    private readonly NotificationService nty;
+    private readonly EmailService mailer;
+    private readonly IStringLocalizer<NotificationResource> localizer;
+    private readonly ICacheService cache;
+    private readonly ILogger<AccountService> logger;
+
+    public AccountService(
+        PassDatabase db,
+        MagicSpellService spells,
+        AccountUsernameService uname,
+        NotificationService nty,
+        EmailService mailer,
+        IStringLocalizer<NotificationResource> localizer,
+        ICacheService cache,
+        ILogger<AccountService> logger
+    )
+    {
+        this.db = db;
+        this.spells = spells;
+        this.uname = uname;
+        this.nty = nty;
+        this.mailer = mailer;
+        this.localizer = localizer;
+        this.cache = cache;
+        this.logger = logger;
+    }
+
+    public static void SetCultureInfo(Models.Account account)
+    {
+        SetCultureInfo(account.Language);
+    }
+
+    public static void SetCultureInfo(string? languageCode)
+    {
+        var info = new CultureInfo(languageCode ?? "en-us", false);
+        CultureInfo.CurrentCulture = info;
+        CultureInfo.CurrentUICulture = info;
+    }
+
+    public const string AccountCachePrefix = "account:";
+
+    public async Task PurgeAccountCache(Models.Account account)
+    {
+        await cache.RemoveGroupAsync($"{AccountCachePrefix}{account.Id}");
+    }
+
+    public async Task<Models.Account?> LookupAccount(string probe)
+    {
+        var account = await db.Accounts.Where(a => a.Name == probe).FirstOrDefaultAsync();
+        if (account is not null) return account;
+
+        var contact = await db.AccountContacts
+            .Where(c => c.Content == probe)
+            .Include(c => c.Account)
+            .FirstOrDefaultAsync();
+        return contact?.Account;
+    }
+
+    public async Task<Models.Account?> LookupAccountByConnection(string identifier, string provider)
+    {
+        var connection = await db.AccountConnections
+            .Where(c => c.ProvidedIdentifier == identifier && c.Provider == provider)
+            .Include(c => c.Account)
+            .FirstOrDefaultAsync();
+        return connection?.Account;
+    }
+
+    public async Task<int?> GetAccountLevel(Guid accountId)
+    {
+        var profile = await db.AccountProfiles
+            .Where(a => a.AccountId == accountId)
+            .FirstOrDefaultAsync();
+        return profile?.Level;
+    }
+
+    public async Task<Models.Account> CreateAccount(
+        string name,
+        string nick,
+        string email,
+        string? password,
+        string language = "en-US",
+        bool isEmailVerified = false,
+        bool isActivated = false
+    )
+    {
+        await using var transaction = await db.Database.BeginTransactionAsync();
+        try
+        {
+            var dupeNameCount = await db.Accounts.Where(a => a.Name == name).CountAsync();
+            if (dupeNameCount > 0)
+                throw new InvalidOperationException("Account name has already been taken.");
+
+            var account = new Models.Account
+            {
+                Name = name,
+                Nick = nick,
+                Language = language,
+                Contacts = new List<AccountContact>
+                {
+                    new()
+                    {
+                        Type = AccountContactType.Email,
+                        Content = email,
+                        VerifiedAt = isEmailVerified ? SystemClock.Instance.GetCurrentInstant() : null,
+                        IsPrimary = true
+                    }
+                },
+                AuthFactors = password is not null
+                    ? new List<AccountAuthFactor>
+                    {
+                        new AccountAuthFactor
+                        {
+                            Type = AccountAuthFactorType.Password,
+                            Secret = password,
+                            EnabledAt = SystemClock.Instance.GetCurrentInstant()
+                        }.HashSecret()
+                    }
+                    : [],
+                Profile = new Profile()
+            };
+
+            if (isActivated)
+            {
+                account.ActivatedAt = SystemClock.Instance.GetCurrentInstant();
+                var defaultGroup = await db.PermissionGroups.FirstOrDefaultAsync(g => g.Key == "default");
+                if (defaultGroup is not null)
+                {
+                    db.PermissionGroupMembers.Add(new PermissionGroupMember
+                    {
+                        Actor = $"user:{account.Id}",
+                        Group = defaultGroup
+                    });
+                }
+            }
+            else
+            {
+                var spell = await spells.CreateMagicSpell(
+                    account,
+                    MagicSpellType.AccountActivation,
+                    new Dictionary<string, object>
+                    {
+                        { "contact_method", account.Contacts.First().Content }
+                    }
+                );
+                await spells.NotifyMagicSpell(spell, true);
+            }
+
+            db.Accounts.Add(account);
+            await db.SaveChangesAsync();
+
+            await transaction.CommitAsync();
+            return account;
+        }
+        catch
+        {
+            await transaction.RollbackAsync();
+            throw;
+        }
+    }
+
+    public async Task<Models.Account> CreateAccount(OidcUserInfo userInfo)
+    {
+        if (string.IsNullOrEmpty(userInfo.Email))
+            throw new ArgumentException("Email is required for account creation");
+
+        var displayName = !string.IsNullOrEmpty(userInfo.DisplayName)
+            ? userInfo.DisplayName
+            : $"{userInfo.FirstName} {userInfo.LastName}".Trim();
+
+        // Generate username from email
+        var username = await uname.GenerateUsernameFromEmailAsync(userInfo.Email);
+
+        return await CreateAccount(
+            username,
+            displayName,
+            userInfo.Email,
+            null,
+            "en-US",
+            userInfo.EmailVerified,
+            userInfo.EmailVerified
+        );
+    }
+
+    public async Task RequestAccountDeletion(Models.Account account)
+    {
+        var spell = await spells.CreateMagicSpell(
+            account,
+            MagicSpellType.AccountRemoval,
+            new Dictionary<string, object>(),
+            SystemClock.Instance.GetCurrentInstant().Plus(Duration.FromHours(24)),
+            preventRepeat: true
+        );
+        await spells.NotifyMagicSpell(spell);
+    }
+
+    public async Task RequestPasswordReset(Models.Account account)
+    {
+        var spell = await spells.CreateMagicSpell(
+            account,
+            MagicSpellType.AuthPasswordReset,
+            new Dictionary<string, object>(),
+            SystemClock.Instance.GetCurrentInstant().Plus(Duration.FromHours(24)),
+            preventRepeat: true
+        );
+        await spells.NotifyMagicSpell(spell);
+    }
+
+    public async Task<bool> CheckAuthFactorExists(Models.Account account, AccountAuthFactorType type)
+    {
+        var isExists = await db.AccountAuthFactors
+            .Where(x => x.AccountId == account.Id && x.Type == type)
+            .AnyAsync();
+        return isExists;
+    }
+
+    public async Task<AccountAuthFactor?> CreateAuthFactor(Models.Account account, AccountAuthFactorType type, string? secret)
+    {
+        AccountAuthFactor? factor = null;
+        switch (type)
+        {
+            case AccountAuthFactorType.Password:
+                if (string.IsNullOrWhiteSpace(secret)) throw new ArgumentNullException(nameof(secret));
+                factor = new AccountAuthFactor
+                {
+                    Type = AccountAuthFactorType.Password,
+                    Trustworthy = 1,
+                    AccountId = account.Id,
+                    Secret = secret,
+                    EnabledAt = SystemClock.Instance.GetCurrentInstant(),
+                }.HashSecret();
+                break;
+            case AccountAuthFactorType.EmailCode:
+                factor = new AccountAuthFactor
+                {
+                    Type = AccountAuthFactorType.EmailCode,
+                    Trustworthy = 2,
+                    EnabledAt = SystemClock.Instance.GetCurrentInstant(),
+                };
+                break;
+            case AccountAuthFactorType.InAppCode:
+                factor = new AccountAuthFactor
+                {
+                    Type = AccountAuthFactorType.InAppCode,
+                    Trustworthy = 1,
+                    EnabledAt = SystemClock.Instance.GetCurrentInstant()
+                };
+                break;
+            case AccountAuthFactorType.TimedCode:
+                var skOtp = KeyGeneration.GenerateRandomKey(20);
+                var skOtp32 = Base32Encoding.ToString(skOtp);
+                factor = new AccountAuthFactor
+                {
+                    Secret = skOtp32,
+                    Type = AccountAuthFactorType.TimedCode,
+                    Trustworthy = 2,
+                    EnabledAt = null, // It needs to be tired once to enable
+                    CreatedResponse = new Dictionary<string, object>
+                    {
+                        ["uri"] = new OtpUri(
+                            OtpType.Totp,
+                            skOtp32,
+                            account.Id.ToString(),
+                            "Solar Network"
+                        ).ToString(),
+                    }
+                };
+                break;
+            case AccountAuthFactorType.PinCode:
+                if (string.IsNullOrWhiteSpace(secret)) throw new ArgumentNullException(nameof(secret));
+                if (!secret.All(char.IsDigit) || secret.Length != 6)
+                    throw new ArgumentException("PIN code must be exactly 6 digits");
+                factor = new AccountAuthFactor
+                {
+                    Type = AccountAuthFactorType.PinCode,
+                    Trustworthy = 0, // Only for confirming, can't be used for login
+                    Secret = secret,
+                    EnabledAt = SystemClock.Instance.GetCurrentInstant(),
+                }.HashSecret();
+                break;
+            default:
+                throw new ArgumentOutOfRangeException(nameof(type), type, null);
+        }
+
+        if (factor is null) throw new InvalidOperationException("Unable to create auth factor.");
+        factor.AccountId = account.Id;
+        db.AccountAuthFactors.Add(factor);
+        await db.SaveChangesAsync();
+        return factor;
+    }
+
+    public async Task<AccountAuthFactor> EnableAuthFactor(AccountAuthFactor factor, string? code)
+    {
+        if (factor.EnabledAt is not null) throw new ArgumentException("The factor has been enabled.");
+        if (factor.Type is AccountAuthFactorType.Password or AccountAuthFactorType.TimedCode)
+        {
+            if (code is null || !factor.VerifyPassword(code))
+                throw new InvalidOperationException(
+                    "Invalid code, you need to enter the correct code to enable the factor."
+                );
+        }
+
+        factor.EnabledAt = SystemClock.Instance.GetCurrentInstant();
+        db.Update(factor);
+        await db.SaveChangesAsync();
+
+        return factor;
+    }
+
+    public async Task<AccountAuthFactor> DisableAuthFactor(AccountAuthFactor factor)
+    {
+        if (factor.EnabledAt is null) throw new ArgumentException("The factor has been disabled.");
+
+        var count = await db.AccountAuthFactors
+            .Where(f => f.AccountId == factor.AccountId && f.EnabledAt != null)
+            .CountAsync();
+        if (count <= 1)
+            throw new InvalidOperationException(
+                "Disabling this auth factor will cause you have no active auth factors.");
+
+        factor.EnabledAt = null;
+        db.Update(factor);
+        await db.SaveChangesAsync();
+
+        return factor;
+    }
+
+    public async Task DeleteAuthFactor(AccountAuthFactor factor)
+    {
+        var count = await db.AccountAuthFactors
+            .Where(f => f.AccountId == factor.AccountId)
+            .If(factor.EnabledAt is not null, q => q.Where(f => f.EnabledAt != null))
+            .CountAsync();
+        if (count <= 1)
+            throw new InvalidOperationException("Deleting this auth factor will cause you have no auth factor.");
+
+        db.AccountAuthFactors.Remove(factor);
+        await db.SaveChangesAsync();
+    }
+
+    /// <summary>
+    /// Send the auth factor verification code to users, for factors like in-app code and email.
+    /// Sometimes it requires a hint, like a part of the user's email address to ensure the user is who own the account.
+    /// </summary>
+    /// <param name="account">The owner of the auth factor</param>
+    /// <param name="factor">The auth factor needed to send code</param>
+    /// <param name="hint">The part of the contact method for verification</param>
+    public async Task SendFactorCode(Models.Account account, AccountAuthFactor factor, string? hint = null)
+    {
+        var code = new Random().Next(100000, 999999).ToString("000000");
+
+        switch (factor.Type)
+        {
+            case AccountAuthFactorType.InAppCode:
+                if (await _GetFactorCode(factor) is not null)
+                    throw new InvalidOperationException("A factor code has been sent and in active duration.");
+
+                await nty.SendNotification(
+                    account,
+                    "auth.verification",
+                    localizer["AuthCodeTitle"],
+                    null,
+                    localizer["AuthCodeBody", code],
+                    save: true
+                );
+                await _SetFactorCode(factor, code, TimeSpan.FromMinutes(5));
+                break;
+            case AccountAuthFactorType.EmailCode:
+                if (await _GetFactorCode(factor) is not null)
+                    throw new InvalidOperationException("A factor code has been sent and in active duration.");
+
+                ArgumentNullException.ThrowIfNull(hint);
+                hint = hint.Replace("@", "").Replace(".", "").Replace("+", "").Replace("%", "");
+                if (string.IsNullOrWhiteSpace(hint))
+                {
+                    logger.LogWarning(
+                        "Unable to send factor code to #{FactorId} with hint {Hint}, due to invalid hint...",
+                        factor.Id,
+                        hint
+                    );
+                    return;
+                }
+
+                var contact = await db.AccountContacts
+                    .Where(c => c.Type == AccountContactType.Email)
+                    .Where(c => c.VerifiedAt != null)
+                    .Where(c => EF.Functions.ILike(c.Content, $"%{hint}%"))
+                    .Include(c => c.Account)
+                    .FirstOrDefaultAsync();
+                if (contact is null)
+                {
+                    logger.LogWarning(
+                        "Unable to send factor code to #{FactorId} with hint {Hint}, due to no contact method found according to hint...",
+                        factor.Id,
+                        hint
+                    );
+                    return;
+                }
+
+                                await mailer.SendTemplatedEmailAsync<DysonNetwork.Sphere.Pages.Emails.VerificationEmail, VerificationEmailModel>(
+                    account.Nick,
+                    contact.Content,
+                    localizer["VerificationEmail"],
+                    new VerificationEmailModel
+                    {
+                        Name = account.Name,
+                        Code = code
+                    }
+                );
+
+                await _SetFactorCode(factor, code, TimeSpan.FromMinutes(30));
+                break;
+            case AccountAuthFactorType.Password:
+            case AccountAuthFactorType.TimedCode:
+            default:
+                // No need to send, such as password etc...
+                return;
+        }
+    }
+
+    public async Task<bool> VerifyFactorCode(AccountAuthFactor factor, string code)
+    {
+        switch (factor.Type)
+        {
+            case AccountAuthFactorType.EmailCode:
+            case AccountAuthFactorType.InAppCode:
+                var correctCode = await _GetFactorCode(factor);
+                var isCorrect = correctCode is not null &&
+                                string.Equals(correctCode, code, StringComparison.OrdinalIgnoreCase);
+                await cache.RemoveAsync($"{AuthFactorCachePrefix}{factor.Id}:code");
+                return isCorrect;
+            case AccountAuthFactorType.Password:
+            case AccountAuthFactorType.TimedCode:
+            default:
+                return factor.VerifyPassword(code);
+        }
+    }
+
+    private const string AuthFactorCachePrefix = "authfactor:";
+
+    private async Task _SetFactorCode(AccountAuthFactor factor, string code, TimeSpan expires)
+    {
+        await cache.SetAsync(
+            $"{AuthFactorCachePrefix}{factor.Id}:code",
+            code,
+            expires
+        );
+    }
+
+    private async Task<string?> _GetFactorCode(AccountAuthFactor factor)
+    {
+        return await cache.GetAsync<string?>(
+            $"{AuthFactorCachePrefix}{factor.Id}:code"
+        );
+    }
+
+    public async Task<Session> UpdateSessionLabel(Models.Account account, Guid sessionId, string label)
+    {
+        var session = await db.AuthSessions
+            .Include(s => s.Challenge)
+            .Where(s => s.Id == sessionId && s.AccountId == account.Id)
+            .FirstOrDefaultAsync();
+        if (session is null) throw new InvalidOperationException("Session was not found.");
+
+        await db.AuthSessions
+            .Include(s => s.Challenge)
+            .Where(s => s.Challenge.DeviceId == session.Challenge.DeviceId)
+            .ExecuteUpdateAsync(p => p.SetProperty(s => s.Label, label));
+
+        var sessions = await db.AuthSessions
+            .Include(s => s.Challenge)
+            .Where(s => s.AccountId == session.Id && s.Challenge.DeviceId == session.Challenge.DeviceId)
+            .ToListAsync();
+        foreach (var item in sessions)
+            await cache.RemoveAsync($"{DysonTokenAuthHandler.AuthCachePrefix}{item.Id}");
+
+        return session;
+    }
+
+    public async Task DeleteSession(Models.Account account, Guid sessionId)
+    {
+        var session = await db.AuthSessions
+            .Include(s => s.Challenge)
+            .Where(s => s.Id == sessionId && s.AccountId == account.Id)
+            .FirstOrDefaultAsync();
+        if (session is null) throw new InvalidOperationException("Session was not found.");
+
+        var sessions = await db.AuthSessions
+            .Include(s => s.Challenge)
+            .Where(s => s.AccountId == session.Id && s.Challenge.DeviceId == session.Challenge.DeviceId)
+            .ToListAsync();
+
+        if (session.Challenge.DeviceId is not null)
+            await nty.UnsubscribePushNotifications(session.Challenge.DeviceId);
+
+        // The current session should be included in the sessions' list
+        await db.AuthSessions
+            .Include(s => s.Challenge)
+            .Where(s => s.Challenge.DeviceId == session.Challenge.DeviceId)
+            .ExecuteDeleteAsync();
+
+        foreach (var item in sessions)
+            await cache.RemoveAsync($"{DysonTokenAuthHandler.AuthCachePrefix}{item.Id}");
+    }
+
+    public async Task<AccountContact> CreateContactMethod(Models.Account account, AccountContactType type, string content)
+    {
+        var contact = new AccountContact
+        {
+            Type = type,
+            Content = content,
+            AccountId = account.Id,
+        };
+
+        db.AccountContacts.Add(contact);
+        await db.SaveChangesAsync();
+
+        return contact;
+    }
+
+    public async Task VerifyContactMethod(Models.Account account, AccountContact contact)
+    {
+        var spell = await spells.CreateMagicSpell(
+            account,
+            MagicSpellType.ContactVerification,
+            new Dictionary<string, object> { { "contact_method", contact.Content } },
+            expiredAt: SystemClock.Instance.GetCurrentInstant().Plus(Duration.FromHours(24)),
+            preventRepeat: true
+        );
+        await spells.NotifyMagicSpell(spell);
+    }
+
+    public async Task<AccountContact> SetContactMethodPrimary(Models.Account account, AccountContact contact)
+    {
+        if (contact.AccountId != account.Id)
+            throw new InvalidOperationException("Contact method does not belong to this account.");
+        if (contact.VerifiedAt is null)
+            throw new InvalidOperationException("Cannot set unverified contact method as primary.");
+
+        await using var transaction = await db.Database.BeginTransactionAsync();
+
+        try
+        {
+            await db.AccountContacts
+                .Where(c => c.AccountId == account.Id && c.Type == contact.Type)
+                .ExecuteUpdateAsync(s => s.SetProperty(x => x.IsPrimary, false));
+
+            contact.IsPrimary = true;
+            db.AccountContacts.Update(contact);
+            await db.SaveChangesAsync();
+
+            await transaction.CommitAsync();
+            return contact;
+        }
+        catch
+        {
+            await transaction.RollbackAsync();
+            throw;
+        }
+    }
+
+    public async Task DeleteContactMethod(Models.Account account, AccountContact contact)
+    {
+        if (contact.AccountId != account.Id)
+            throw new InvalidOperationException("Contact method does not belong to this account.");
+        if (contact.IsPrimary)
+            throw new InvalidOperationException("Cannot delete primary contact method.");
+
+        db.AccountContacts.Remove(contact);
+        await db.SaveChangesAsync();
+    }
+
+    /// <summary>
+    /// This method will grant a badge to the account.
+    /// Shouldn't be exposed to normal user and the user itself.
+    /// </summary>
+    public async Task<Badge> GrantBadge(Models.Account account, Badge badge)
+    {
+        badge.AccountId = account.Id;
+        db.Badges.Add(badge);
+        await db.SaveChangesAsync();
+        return badge;
+    }
+
+    /// <summary>
+    /// This method will revoke a badge from the account.
+    /// Shouldn't be exposed to normal user and the user itself.
+    /// </summary>
+    public async Task RevokeBadge(Models.Account account, Guid badgeId)
+    {
+        var badge = await db.Badges
+            .Where(b => b.AccountId == account.Id && b.Id == badgeId)
+            .OrderByDescending(b => b.CreatedAt)
+            .FirstOrDefaultAsync();
+        if (badge is null) throw new InvalidOperationException("Badge was not found.");
+
+        var profile = await db.AccountProfiles
+            .Where(p => p.AccountId == account.Id)
+            .FirstOrDefaultAsync();
+        if (profile?.ActiveBadge is not null && profile.ActiveBadge.Id == badge.Id)
+            profile.ActiveBadge = null;
+
+        db.Remove(badge);
+        await db.SaveChangesAsync();
+    }
+
+    public async Task ActiveBadge(Models.Account account, Guid badgeId)
+    {
+        await using var transaction = await db.Database.BeginTransactionAsync();
+
+        try
+        {
+            var badge = await db.Badges
+                .Where(b => b.AccountId == account.Id && b.Id == badgeId)
+                .OrderByDescending(b => b.CreatedAt)
+                .FirstOrDefaultAsync();
+            if (badge is null) throw new InvalidOperationException("Badge was not found.");
+
+            await db.Badges
+                .Where(b => b.AccountId == account.Id && b.Id != badgeId)
+                .ExecuteUpdateAsync(s => s.SetProperty(p => p.ActivatedAt, p => null));
+
+            badge.ActivatedAt = SystemClock.Instance.GetCurrentInstant();
+            db.Update(badge);
+            await db.SaveChangesAsync();
+
+            await db.AccountProfiles
+                .Where(p => p.AccountId == account.Id)
+                .ExecuteUpdateAsync(s => s.SetProperty(p => p.ActiveBadge, badge.ToReference()));
+            await PurgeAccountCache(account);
+
+            await transaction.CommitAsync();
+        }
+        catch
+        {
+            await transaction.RollbackAsync();
+            throw;
+        }
+    }
+
+    /// <summary>
+    /// The maintenance method for server administrator.
+    /// To check every user has an account profile and to create them if it isn't having one.
+    /// </summary>
+    public async Task EnsureAccountProfileCreated()
+    {
+        var accountsId = await db.Accounts.Select(a => a.Id).ToListAsync();
+        var existingId = await db.AccountProfiles.Select(p => p.AccountId).ToListAsync();
+        var missingId = accountsId.Except(existingId).ToList();
+
+        if (missingId.Count != 0)
+        {
+            var newProfiles = missingId.Select(id => new Profile { Id = Guid.NewGuid(), AccountId = id }).ToList();
+            await db.BulkInsertAsync(newProfiles);
+        }
+    }
+}

DysonNetwork.Pass/Features/Account/Services/AccountUsernameService.cs

@@ -0,0 +1,105 @@
+using System.Text.RegularExpressions;
+using Microsoft.EntityFrameworkCore;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+/// <summary>
+/// Service for handling username generation and validation
+/// </summary>
+public class AccountUsernameService(AppDatabase db) : IAccountUsernameService
+{
+    private readonly Random _random = new();
+
+    /// <summary>
+    /// Generates a unique username based on the provided base name
+    /// </summary>
+    /// <param name="baseName">The preferred username</param>
+    /// <returns>A unique username</returns>
+    public async Task<string> GenerateUniqueUsernameAsync(string baseName)
+    {
+        // Sanitize the base name
+        var sanitized = SanitizeUsername(baseName);
+
+        // If the base name is empty after sanitization, use a default
+        if (string.IsNullOrEmpty(sanitized))
+        {
+            sanitized = "user";
+        }
+
+        // Check if the sanitized name is available
+        if (!await IsUsernameExistsAsync(sanitized))
+        {
+            return sanitized;
+        }
+
+        // Try up to 10 times with random numbers
+        for (int i = 0; i < 10; i++)
+        {
+            var suffix = _random.Next(1000, 9999);
+            var candidate = $"{sanitized}{suffix}";
+
+            if (!await IsUsernameExistsAsync(candidate))
+            {
+                return candidate;
+            }
+        }
+
+        // If all attempts fail, use a timestamp
+        var timestamp = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
+        return $"{sanitized}{timestamp}";
+    }
+
+    /// <summary>
+    /// Sanitizes a username by removing invalid characters and converting to lowercase
+    /// </summary>
+    public string SanitizeUsername(string username)
+    {
+        if (string.IsNullOrEmpty(username))
+            return string.Empty;
+
+        // Replace spaces and special characters with underscores
+        var sanitized = Regex.Replace(username, @"[^a-zA-Z0-9_\-]", "");
+
+        // Convert to lowercase
+        sanitized = sanitized.ToLowerInvariant();
+
+        // Ensure it starts with a letter
+        if (sanitized.Length > 0 && !char.IsLetter(sanitized[0]))
+        {
+            sanitized = "u" + sanitized;
+        }
+
+        // Truncate if too long
+        if (sanitized.Length > 30)
+        {
+            sanitized = sanitized[..30];
+        }
+
+        return sanitized;
+    }
+
+    /// <summary>
+    /// Checks if a username already exists
+    /// </summary>
+    public async Task<bool> IsUsernameExistsAsync(string username)
+    {
+        return await db.Accounts.AnyAsync(a => a.Name == username);
+    }
+
+    /// <summary>
+    /// Generates a username from an email address
+    /// </summary>
+    /// <param name="email">The email address to generate a username from</param>
+    /// <returns>A unique username derived from the email</returns>
+    public async Task<string> GenerateUsernameFromEmailAsync(string email)
+    {
+        if (string.IsNullOrEmpty(email))
+            return await GenerateUniqueUsernameAsync("user");
+
+        // Extract the local part of the email (before the @)
+        var localPart = email.Split('@')[0];
+
+        // Use the local part as the base for username generation
+        return await GenerateUniqueUsernameAsync(localPart);
+    }
+}

DysonNetwork.Pass/Features/Account/Services/ActionLogService.cs

@@ -0,0 +1,45 @@
+using DysonNetwork.Pass.Connection;
+using DysonNetwork.Pass.Storage;
+using DysonNetwork.Pass.Storage.Handlers;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+public class ActionLogService(GeoIpService geo, FlushBufferService fbs) : IActionLogService
+{
+    public void CreateActionLog(Guid accountId, string action, Dictionary<string, object> meta)
+    {
+        var log = new ActionLog
+        {
+            Action = action,
+            AccountId = accountId,
+            Meta = meta,
+        };
+
+        fbs.Enqueue(log);
+    }
+
+    public void CreateActionLogFromRequest(string action, Dictionary<string, object> meta, HttpRequest request,
+        Models.Account? account = null)
+    {
+        var log = new ActionLog
+        {
+            Action = action,
+            Meta = meta,
+            UserAgent = request.Headers.UserAgent,
+            IpAddress = request.HttpContext.Connection.RemoteIpAddress?.ToString(),
+            Location = geo.GetPointFromIp(request.HttpContext.Connection.RemoteIpAddress?.ToString())
+        };
+        
+        if (request.HttpContext.Items["CurrentUser"] is Models.Account currentUser)
+            log.AccountId = currentUser.Id;
+        else if (account != null)
+            log.AccountId = account.Id;
+        else
+            throw new ArgumentException("No user context was found");
+        
+        if (request.HttpContext.Items["CurrentSession"] is Auth.Session currentSession)
+            log.SessionId = currentSession.Id;
+
+        fbs.Enqueue(log);
+    }
+}

DysonNetwork.Pass/Features/Account/Services/MagicSpellService.cs

@@ -0,0 +1,259 @@
+
+
+using DysonNetwork.Common.Models;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+public class MagicSpellService
+{
+    private readonly PassDatabase db;
+    private readonly EmailService email;
+    private readonly IConfiguration configuration;
+    private readonly ILogger<MagicSpellService> logger;
+    private readonly IStringLocalizer<Localization.EmailResource> localizer;
+
+    public MagicSpellService(
+        PassDatabase db,
+        EmailService email,
+        IConfiguration configuration,
+        ILogger<MagicSpellService> logger,
+        IStringLocalizer<Localization.EmailResource> localizer
+    )
+    {
+        this.db = db;
+        this.email = email;
+        this.configuration = configuration;
+        this.logger = logger;
+        this.localizer = localizer;
+    }
+
+    public async Task<MagicSpell> CreateMagicSpell(
+        Models.Account account,
+        MagicSpellType type,
+        Dictionary<string, object> meta,
+        Instant? expiredAt = null,
+        Instant? affectedAt = null,
+        bool preventRepeat = false
+    )
+    {
+        if (preventRepeat)
+        {
+            var now = SystemClock.Instance.GetCurrentInstant();
+            var existingSpell = await db.MagicSpells
+                .Where(s => s.AccountId == account.Id)
+                .Where(s => s.Type == type)
+                .Where(s => s.ExpiresAt == null || s.ExpiresAt > now)
+                .FirstOrDefaultAsync();
+
+            if (existingSpell != null)
+            {
+                throw new InvalidOperationException($"Account already has an active magic spell of type {type}");
+            }
+        }
+
+        var spellWord = _GenerateRandomString(128);
+        var spell = new MagicSpell
+        {
+            Spell = spellWord,
+            Type = type,
+            ExpiresAt = expiredAt,
+            AffectedAt = affectedAt,
+            AccountId = account.Id,
+            Meta = meta
+        };
+
+        db.MagicSpells.Add(spell);
+        await db.SaveChangesAsync();
+
+        return spell;
+    }
+
+    public async Task NotifyMagicSpell(MagicSpell spell, bool bypassVerify = false)
+    {
+        var contact = await db.AccountContacts
+            .Where(c => c.Account.Id == spell.AccountId)
+            .Where(c => c.Type == AccountContactType.Email)
+            .Where(c => c.VerifiedAt != null || bypassVerify)
+            .OrderByDescending(c => c.IsPrimary)
+            .Include(c => c.Account)
+            .FirstOrDefaultAsync();
+        if (contact is null) throw new ArgumentException("Account has no contact method that can use");
+
+        var link = $"{configuration.GetValue<string>("BaseUrl")}/spells/{Uri.EscapeDataString(spell.Spell)}";
+
+        logger.LogInformation("Sending magic spell... {Link}", link);
+
+        var accountLanguage = await db.Accounts
+            .Where(a => a.Id == spell.AccountId)
+            .Select(a => a.Language)
+            .FirstOrDefaultAsync();
+        AccountService.SetCultureInfo(accountLanguage);
+
+        try
+        {
+            switch (spell.Type)
+            {
+                case MagicSpellType.AccountActivation:
+                    await email.SendTemplatedEmailAsync<LandingEmail, LandingEmailModel>(
+                        contact.Account.Nick,
+                        contact.Content,
+                        localizer["EmailLandingTitle"],
+                        new LandingEmailModel
+                        {
+                            Name = contact.Account.Name,
+                            Link = link
+                        }
+                    );
+                    break;
+                case MagicSpellType.AccountRemoval:
+                    await email.SendTemplatedEmailAsync<AccountDeletionEmail, AccountDeletionEmailModel>(
+                        contact.Account.Nick,
+                        contact.Content,
+                        localizer["EmailAccountDeletionTitle"],
+                        new AccountDeletionEmailModel
+                        {
+                            Name = contact.Account.Name,
+                            Link = link
+                        }
+                    );
+                    break;
+                case MagicSpellType.AuthPasswordReset:
+                    await email.SendTemplatedEmailAsync<PasswordResetEmail, PasswordResetEmailModel>(
+                        contact.Account.Nick,
+                        contact.Content,
+                        localizer["EmailAccountDeletionTitle"],
+                        new PasswordResetEmailModel
+                        {
+                            Name = contact.Account.Name,
+                            Link = link
+                        }
+                    );
+                    break;
+                case MagicSpellType.ContactVerification:
+                    if (spell.Meta["contact_method"] is not string contactMethod)
+                        throw new InvalidOperationException("Contact method is not found.");
+                    await email.SendTemplatedEmailAsync<ContactVerificationEmail, ContactVerificationEmailModel>(
+                        contact.Account.Nick,
+                        contactMethod!,
+                        localizer["EmailContactVerificationTitle"],
+                        new ContactVerificationEmailModel
+                        {
+                            Name = contact.Account.Name,
+                            Link = link
+                        }
+                    );
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException();
+            }
+        }
+        catch (Exception err)
+        {
+            logger.LogError($"Error sending magic spell (${spell.Spell})... {err}");
+        }
+    }
+
+    public async Task ApplyMagicSpell(MagicSpell spell)
+    {
+        switch (spell.Type)
+        {
+            case MagicSpellType.AuthPasswordReset:
+                throw new ArgumentException(
+                    "For password reset spell, please use the ApplyPasswordReset method instead."
+                );
+            case MagicSpellType.AccountRemoval:
+                var account = await db.Accounts.FirstOrDefaultAsync(c => c.Id == spell.AccountId);
+                if (account is null) break;
+                db.Accounts.Remove(account);
+                break;
+            case MagicSpellType.AccountActivation:
+                var contactMethod = (spell.Meta["contact_method"] as JsonElement? ?? default).ToString();
+                var contact = await
+                    db.AccountContacts.FirstOrDefaultAsync(c =>
+                        c.Content == contactMethod
+                    );
+                if (contact is not null)
+                {
+                    contact.VerifiedAt = SystemClock.Instance.GetCurrentInstant();
+                    db.Update(contact);
+                }
+
+                account = await db.Accounts.FirstOrDefaultAsync(c => c.Id == spell.AccountId);
+                if (account is not null)
+                {
+                    account.ActivatedAt = SystemClock.Instance.GetCurrentInstant();
+                    db.Update(account);
+                }
+
+                var defaultGroup = await db.PermissionGroups.FirstOrDefaultAsync(g => g.Key == "default");
+                if (defaultGroup is not null && account is not null)
+                {
+                    db.PermissionGroupMembers.Add(new PermissionGroupMember
+                    {
+                        Actor = $"user:{account.Id}",
+                        Group = defaultGroup
+                    });
+                }
+
+                break;
+            case MagicSpellType.ContactVerification:
+                var verifyContactMethod = (spell.Meta["contact_method"] as JsonElement? ?? default).ToString();
+                var verifyContact = await db.AccountContacts
+                    .FirstOrDefaultAsync(c => c.Content == verifyContactMethod);
+                if (verifyContact is not null)
+                {
+                    verifyContact.VerifiedAt = SystemClock.Instance.GetCurrentInstant();
+                    db.Update(verifyContact);
+                }
+
+                break;
+            default:
+                throw new ArgumentOutOfRangeException();
+        }
+
+        db.Remove(spell);
+        await db.SaveChangesAsync();
+    }
+
+    public async Task ApplyPasswordReset(MagicSpell spell, string newPassword)
+    {
+        if (spell.Type != MagicSpellType.AuthPasswordReset)
+            throw new ArgumentException("This spell is not a password reset spell.");
+
+        var passwordFactor = await db.AccountAuthFactors
+            .Include(f => f.Account)
+            .Where(f => f.Type == AccountAuthFactorType.Password && f.Account.Id == spell.AccountId)
+            .FirstOrDefaultAsync();
+        if (passwordFactor is null)
+        {
+            var account = await db.Accounts.FirstOrDefaultAsync(c => c.Id == spell.AccountId);
+            if (account is null) throw new InvalidOperationException("Both account and auth factor was not found.");
+            passwordFactor = new AccountAuthFactor
+            {
+                Type = AccountAuthFactorType.Password,
+                Account = account,
+                Secret = newPassword
+            }.HashSecret();
+            db.AccountAuthFactors.Add(passwordFactor);
+        }
+        else
+        {
+            passwordFactor.Secret = newPassword;
+            passwordFactor.HashSecret();
+            db.Update(passwordFactor);
+        }
+
+        await db.SaveChangesAsync();
+    }
+
+    private static string _GenerateRandomString(int length)
+    {
+        using var rng = RandomNumberGenerator.Create();
+        var randomBytes = new byte[length];
+        rng.GetBytes(randomBytes);
+
+        var base64String = Convert.ToBase64String(randomBytes);
+
+        return base64String.Substring(0, length);
+    }
+}

DysonNetwork.Pass/Features/Account/Services/NotificationService.cs

@@ -0,0 +1,286 @@
+using System.Text;
+using System.Text.Json;
+using DysonNetwork.Pass.Connection;
+using EFCore.BulkExtensions;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Common.Models;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+public class NotificationService(
+    PassDatabase db,
+    IConfiguration config) : INotificationService
+{
+    private readonly string _notifyTopic = config["Notifications:Topic"]!;
+    private readonly Uri _notifyEndpoint = new(config["Notifications:Endpoint"]!);
+
+    public async Task UnsubscribePushNotifications(string deviceId)
+    {
+        await db.NotificationPushSubscriptions
+            .Where(s => s.DeviceId == deviceId)
+            .ExecuteDeleteAsync();
+    }
+
+    public async Task<NotificationPushSubscription> SubscribePushNotification(
+        Models.Account account,
+        NotificationPushProvider provider,
+        string deviceId,
+        string deviceToken
+    )
+    {
+        var now = SystemClock.Instance.GetCurrentInstant();
+        
+        // First check if a matching subscription exists
+        var existingSubscription = await db.NotificationPushSubscriptions
+            .Where(s => s.AccountId == account.Id)
+            .Where(s => s.DeviceId == deviceId || s.DeviceToken == deviceToken)
+            .FirstOrDefaultAsync();
+
+        if (existingSubscription is not null)
+        {
+            // Update the existing subscription directly in the database
+            await db.NotificationPushSubscriptions
+                .Where(s => s.Id == existingSubscription.Id)
+                .ExecuteUpdateAsync(setters => setters
+                    .SetProperty(s => s.DeviceId, deviceId)
+                    .SetProperty(s => s.DeviceToken, deviceToken)
+                    .SetProperty(s => s.UpdatedAt, now));
+
+            // Return the updated subscription
+            existingSubscription.DeviceId = deviceId;
+            existingSubscription.DeviceToken = deviceToken;
+            existingSubscription.UpdatedAt = now;
+            return existingSubscription;
+        }
+
+        var subscription = new NotificationPushSubscription
+        {
+            DeviceId = deviceId,
+            DeviceToken = deviceToken,
+            Provider = provider,
+            AccountId = account.Id,
+        };
+
+        db.NotificationPushSubscriptions.Add(subscription);
+        await db.SaveChangesAsync();
+
+        return subscription;
+    }
+
+    public async Task<Notification> SendNotification(
+        Models.Account account,
+        string topic,
+        string? title = null,
+        string? subtitle = null,
+        string? content = null,
+        Dictionary<string, object>? meta = null,
+        string? actionUri = null,
+        bool isSilent = false,
+        bool save = true
+    )
+    {
+        if (title is null && subtitle is null && content is null)
+            throw new ArgumentException("Unable to send notification that completely empty.");
+
+        meta ??= new Dictionary<string, object>();
+        if (actionUri is not null) meta["action_uri"] = actionUri;
+
+        var notification = new Notification
+        {
+            Topic = topic,
+            Title = title,
+            Subtitle = subtitle,
+            Content = content,
+            Meta = meta,
+            AccountId = account.Id,
+        };
+
+        if (save)
+        {
+            db.Add(notification);
+            await db.SaveChangesAsync();
+        }
+
+        if (!isSilent) _ = DeliveryNotification(notification);
+
+        return notification;
+    }
+
+    public async Task DeliveryNotification(Notification notification)
+    {
+        
+
+        // Pushing the notification
+        var subscribers = await db.NotificationPushSubscriptions
+            .Where(s => s.AccountId == notification.AccountId)
+            .ToListAsync();
+
+        await _PushNotification(notification, subscribers);
+    }
+
+    public async Task MarkNotificationsViewed(ICollection<Notification> notifications)
+    {
+        var now = SystemClock.Instance.GetCurrentInstant();
+        var id = notifications.Where(n => n.ViewedAt == null).Select(n => n.Id).ToList();
+        if (id.Count == 0) return;
+
+        await db.Notifications
+            .Where(n => id.Contains(n.Id))
+            .ExecuteUpdateAsync(s => s.SetProperty(n => n.ViewedAt, now)
+            );
+    }
+
+    public async Task BroadcastNotification(Notification notification, bool save = false)
+    {
+        var accounts = await db.Accounts.ToListAsync();
+
+        if (save)
+        {
+            var notifications = accounts.Select(x =>
+            {
+                var newNotification = new Notification
+                {
+                    Topic = notification.Topic,
+                    Title = notification.Title,
+                    Subtitle = notification.Subtitle,
+                    Content = notification.Content,
+                    Meta = notification.Meta,
+                    Priority = notification.Priority,
+                    Account = x,
+                    AccountId = x.Id
+                };
+                return newNotification;
+            }).ToList();
+            await db.BulkInsertAsync(notifications);
+        }
+
+
+
+        var subscribers = await db.NotificationPushSubscriptions
+            .ToListAsync();
+        await _PushNotification(notification, subscribers);
+    }
+
+    public async Task SendNotificationBatch(Notification notification, List<Models.Account> accounts, bool save = false)
+    {
+        if (save)
+        {
+            var notifications = accounts.Select(x =>
+            {
+                var newNotification = new Notification
+                {
+                    Topic = notification.Topic,
+                    Title = notification.Title,
+                    Subtitle = notification.Subtitle,
+                    Content = notification.Content,
+                    Meta = notification.Meta,
+                    Priority = notification.Priority,
+                    Account = x,
+                    AccountId = x.Id
+                };
+                return newNotification;
+            }).ToList();
+            await db.BulkInsertAsync(notifications);
+        }
+
+
+
+        var accountsId = accounts.Select(x => x.Id).ToList();
+        var subscribers = await db.NotificationPushSubscriptions
+            .Where(s => accountsId.Contains(s.AccountId))
+            .ToListAsync();
+        await _PushNotification(notification, subscribers);
+    }
+
+    private List<Dictionary<string, object>> _BuildNotificationPayload(Notification notification,
+        IEnumerable<NotificationPushSubscription> subscriptions)
+    {
+        var subDict = subscriptions
+            .GroupBy(x => x.Provider)
+            .ToDictionary(x => x.Key, x => x.ToList());
+
+        var notifications = subDict.Select(value =>
+        {
+            var platformCode = value.Key switch
+            {
+                NotificationPushProvider.Apple => 1,
+                NotificationPushProvider.Google => 2,
+                _ => throw new InvalidOperationException($"Unknown push provider: {value.Key}")
+            };
+
+            var tokens = value.Value.Select(x => x.DeviceToken).ToList();
+            return _BuildNotificationPayload(notification, platformCode, tokens);
+        }).ToList();
+
+        return notifications.ToList();
+    }
+
+    private Dictionary<string, object> _BuildNotificationPayload(Notification notification, int platformCode,
+        IEnumerable<string> deviceTokens)
+    {
+        var alertDict = new Dictionary<string, object>();
+        var dict = new Dictionary<string, object>
+        {
+            ["notif_id"] = notification.Id.ToString(),
+            ["apns_id"] = notification.Id.ToString(),
+            ["topic"] = _notifyTopic,
+            ["tokens"] = deviceTokens,
+            ["data"] = new Dictionary<string, object>
+            {
+                ["type"] = notification.Topic,
+                ["meta"] = notification.Meta ?? new Dictionary<string, object>(),
+            },
+            ["mutable_content"] = true,
+            ["priority"] = notification.Priority >= 5 ? "high" : "normal",
+        };
+
+        if (!string.IsNullOrWhiteSpace(notification.Title))
+        {
+            dict["title"] = notification.Title;
+            alertDict["title"] = notification.Title;
+        }
+
+        if (!string.IsNullOrWhiteSpace(notification.Content))
+        {
+            dict["message"] = notification.Content;
+            alertDict["body"] = notification.Content;
+        }
+
+        if (!string.IsNullOrWhiteSpace(notification.Subtitle))
+        {
+            dict["message"] = $"{notification.Subtitle}\n{dict["message"]}";
+            alertDict["subtitle"] = notification.Subtitle;
+        }
+
+        if (notification.Priority >= 5)
+            dict["name"] = "default";
+
+        dict["platform"] = platformCode;
+        dict["alert"] = alertDict;
+
+        return dict;
+    }
+
+    private async Task _PushNotification(Notification notification,
+        IEnumerable<NotificationPushSubscription> subscriptions)
+    {
+        var subList = subscriptions.ToList();
+        if (subList.Count == 0) return;
+
+        var requestDict = new Dictionary<string, object>
+        {
+            ["notifications"] = _BuildNotificationPayload(notification, subList)
+        };
+
+        var client = httpFactory.CreateClient();
+        client.BaseAddress = _notifyEndpoint;
+        var request = await client.PostAsync("/push", new StringContent(
+            JsonSerializer.Serialize(requestDict),
+            Encoding.UTF8,
+            "application/json"
+        ));
+        request.EnsureSuccessStatusCode();
+    }
+}

DysonNetwork.Pass/Features/Account/Services/RelationshipService.cs

@@ -0,0 +1,210 @@
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Pass.Storage;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+using DysonNetwork.Common.Models;
+using DysonNetwork.Pass.Permission;
+
+namespace DysonNetwork.Pass.Features.Account;
+
+public class RelationshipService(PassDatabase db, ICacheService cache) : IRelationshipService
+{
+    private const string UserFriendsCacheKeyPrefix = "accounts:friends:";
+    private const string UserBlockedCacheKeyPrefix = "accounts:blocked:";
+    
+    public async Task<bool> HasExistingRelationship(Guid accountId, Guid relatedId)
+    {
+        var count = await db.AccountRelationships
+            .Where(r => (r.AccountId == accountId && r.RelatedId == relatedId) ||
+                        (r.AccountId == relatedId && r.AccountId == accountId))
+            .CountAsync();
+        return count > 0;
+    }
+
+    public async Task<Relationship?> GetRelationship(
+        Guid accountId,
+        Guid relatedId,
+        RelationshipStatus? status = null,
+        bool ignoreExpired = false
+    )
+    {
+        var now = Instant.FromDateTimeUtc(DateTime.UtcNow);
+        var queries = db.AccountRelationships.AsQueryable()
+            .Where(r => r.AccountId == accountId && r.RelatedId == relatedId);
+        if (!ignoreExpired) queries = queries.Where(r => r.ExpiredAt == null || r.ExpiredAt > now);
+        if (status is not null) queries = queries.Where(r => r.Status == status);
+        var relationship = await queries.FirstOrDefaultAsync();
+        return relationship;
+    }
+
+    public async Task<Relationship> CreateRelationship(Models.Account sender, Models.Account target, RelationshipStatus status)
+    {
+        if (status == RelationshipStatus.Pending)
+            throw new InvalidOperationException(
+                "Cannot create relationship with pending status, use SendFriendRequest instead.");
+        if (await HasExistingRelationship(sender.Id, target.Id))
+            throw new InvalidOperationException("Found existing relationship between you and target user.");
+
+        var relationship = new Relationship
+        {
+            AccountId = sender.Id,
+            RelatedId = target.Id,
+            Status = status
+        };
+
+        db.AccountRelationships.Add(relationship);
+        await db.SaveChangesAsync();
+        
+        await PurgeRelationshipCache(sender.Id, target.Id);
+
+        return relationship;
+    }
+
+    public async Task<Relationship> BlockAccount(Models.Account sender, Models.Account target)
+    {
+        if (await HasExistingRelationship(sender.Id, target.Id))
+            return await UpdateRelationship(sender.Id, target.Id, RelationshipStatus.Blocked);
+        return await CreateRelationship(sender, target, RelationshipStatus.Blocked);
+    }
+    
+    public async Task<Relationship> UnblockAccount(Models.Account sender, Models.Account target)
+    {
+        var relationship = await GetRelationship(sender.Id, target.Id, RelationshipStatus.Blocked);
+        if (relationship is null) throw new ArgumentException("There is no relationship between you and the user.");
+        db.Remove(relationship);
+        await db.SaveChangesAsync();
+        
+        await PurgeRelationshipCache(sender.Id, target.Id);
+        
+        return relationship;
+    }
+
+    public async Task<Relationship> SendFriendRequest(Models.Account sender, Models.Account target)
+    {
+        if (await HasExistingRelationship(sender.Id, target.Id))
+            throw new InvalidOperationException("Found existing relationship between you and target user.");
+
+        var relationship = new Relationship
+        {
+            AccountId = sender.Id,
+            RelatedId = target.Id,
+            Status = RelationshipStatus.Pending,
+            ExpiredAt = Instant.FromDateTimeUtc(DateTime.UtcNow.AddDays(7))
+        };
+
+        db.AccountRelationships.Add(relationship);
+        await db.SaveChangesAsync();
+
+        return relationship;
+    }
+    
+    public async Task DeleteFriendRequest(Guid accountId, Guid relatedId)
+    {
+        var relationship = await GetRelationship(accountId, relatedId, RelationshipStatus.Pending);
+        if (relationship is null) throw new ArgumentException("Friend request was not found.");
+    
+        await db.AccountRelationships
+            .Where(r => r.AccountId == accountId && r.RelatedId == relatedId && r.Status == RelationshipStatus.Pending)
+            .ExecuteDeleteAsync();
+        
+        await PurgeRelationshipCache(relationship.AccountId, relationship.RelatedId);
+    }
+    
+    public async Task<Relationship> AcceptFriendRelationship(
+        Relationship relationship,
+        RelationshipStatus status = RelationshipStatus.Friends
+    )
+    {
+        if (relationship.Status != RelationshipStatus.Pending)
+            throw new ArgumentException("Cannot accept friend request that not in pending status.");
+        if (status == RelationshipStatus.Pending)
+            throw new ArgumentException("Cannot accept friend request by setting the new status to pending.");
+
+        // Whatever the receiver decides to apply which status to the relationship,
+        // the sender should always see the user as a friend since the sender ask for it
+        relationship.Status = RelationshipStatus.Friends;
+        relationship.ExpiredAt = null;
+        db.Update(relationship);
+
+        var relationshipBackward = new Relationship
+        {
+            AccountId = relationship.RelatedId,
+            RelatedId = relationship.AccountId,
+            Status = status
+        };
+        db.AccountRelationships.Add(relationshipBackward);
+
+        await db.SaveChangesAsync();
+
+        await PurgeRelationshipCache(relationship.AccountId, relationship.RelatedId);
+
+        return relationshipBackward;
+    }
+
+    public async Task<Relationship> UpdateRelationship(Guid accountId, Guid relatedId, RelationshipStatus status)
+    {
+        var relationship = await GetRelationship(accountId, relatedId);
+        if (relationship is null) throw new ArgumentException("There is no relationship between you and the user.");
+        if (relationship.Status == status) return relationship;
+        relationship.Status = status;
+        db.Update(relationship);
+        await db.SaveChangesAsync();
+        
+        await PurgeRelationshipCache(accountId, relatedId);
+        
+        return relationship;
+    }
+
+    public async Task<List<Guid>> ListAccountFriends(Models.Account account)
+    {
+        var cacheKey = $"{UserFriendsCacheKeyPrefix}{account.Id}";
+        var friends = await cache.GetAsync<List<Guid>>(cacheKey);
+        
+        if (friends == null)
+        {
+            friends = await db.AccountRelationships
+                .Where(r => r.RelatedId == account.Id)
+                .Where(r => r.Status == RelationshipStatus.Friends)
+                .Select(r => r.AccountId)
+                .ToListAsync();
+                
+            await cache.SetAsync(cacheKey, friends, TimeSpan.FromHours(1));
+        }
+
+        return friends ?? [];
+    }
+    
+    public async Task<List<Guid>> ListAccountBlocked(Models.Account account)
+    {
+        var cacheKey = $"{UserBlockedCacheKeyPrefix}{account.Id}";
+        var blocked = await cache.GetAsync<List<Guid>>(cacheKey);
+        
+        if (blocked == null)
+        {
+            blocked = await db.AccountRelationships
+                .Where(r => r.RelatedId == account.Id)
+                .Where(r => r.Status == RelationshipStatus.Blocked)
+                .Select(r => r.AccountId)
+                .ToListAsync();
+                
+            await cache.SetAsync(cacheKey, blocked, TimeSpan.FromHours(1));
+        }
+
+        return blocked ?? [];
+    }
+
+    public async Task<bool> HasRelationshipWithStatus(Guid accountId, Guid relatedId,
+        RelationshipStatus status = RelationshipStatus.Friends)
+    {
+        var relationship = await GetRelationship(accountId, relatedId, status);
+        return relationship is not null;
+    }
+    
+    private async Task PurgeRelationshipCache(Guid accountId, Guid relatedId)
+    {
+        await cache.RemoveAsync($"{UserFriendsCacheKeyPrefix}{accountId}");
+        await cache.RemoveAsync($"{UserFriendsCacheKeyPrefix}{relatedId}");
+        await cache.RemoveAsync($"{UserBlockedCacheKeyPrefix}{accountId}");
+        await cache.RemoveAsync($"{UserBlockedCacheKeyPrefix}{relatedId}");
+    }
+}

DysonNetwork.Pass/Features/Auth/Controllers/AuthController.cs

@@ -0,0 +1,248 @@
+using System.ComponentModel.DataAnnotations;
+using DysonNetwork.Pass.Features.Account;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using NodaTime;
+using Microsoft.EntityFrameworkCore;
+using System.IdentityModel.Tokens.Jwt;
+using System.Text.Json;
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Common.Models;
+
+namespace DysonNetwork.Pass.Features.Auth;
+
+[ApiController]
+[Route("/auth")]
+public class AuthController(
+    PassDatabase db,
+    AccountService accounts,
+    AuthService auth
+) : ControllerBase
+{
+    public class ChallengeRequest
+    {
+        [Required] public ChallengePlatform Platform { get; set; }
+        [Required] [MaxLength(256)] public string Account { get; set; } = null!;
+        [Required] [MaxLength(512)] public string DeviceId { get; set; } = null!;
+        public List<string> Audiences { get; set; } = new();
+        public List<string> Scopes { get; set; } = new();
+    }
+
+    [HttpPost("challenge")]
+    public async Task<ActionResult<Challenge>> StartChallenge([FromBody] ChallengeRequest request)
+    {
+        var account = await accounts.LookupAccount(request.Account);
+        if (account is null) return NotFound("Account was not found.");
+
+        var ipAddress = HttpContext.Connection.RemoteIpAddress?.ToString();
+        var userAgent = HttpContext.Request.Headers.UserAgent.ToString();
+
+        var now = Instant.FromDateTimeUtc(DateTime.UtcNow);
+
+        // Trying to pick up challenges from the same IP address and user agent
+        var existingChallenge = await db.AuthChallenges
+            .Where(e => e.Account == account)
+            .Where(e => e.IpAddress == ipAddress)
+            .Where(e => e.UserAgent == userAgent)
+            .Where(e => e.StepRemain > 0)
+            .Where(e => e.ExpiredAt != null && now < e.ExpiredAt)
+            .FirstOrDefaultAsync();
+        if (existingChallenge is not null) return existingChallenge;
+
+        var challenge = new Challenge
+        {
+            ExpiredAt = Instant.FromDateTimeUtc(DateTime.UtcNow.AddHours(1)),
+            StepTotal = await auth.DetectChallengeRisk(Request, account),
+            Platform = request.Platform,
+            Audiences = request.Audiences,
+            Scopes = request.Scopes,
+            IpAddress = ipAddress,
+            UserAgent = userAgent,
+            
+            DeviceId = request.DeviceId,
+            AccountId = account.Id
+        }.Normalize();
+
+        await db.AuthChallenges.AddAsync(challenge);
+        await db.SaveChangesAsync();
+
+        
+
+        return challenge;
+    }
+
+    [HttpGet("challenge/{id:guid}")]
+    public async Task<ActionResult<Challenge>> GetChallenge([FromRoute] Guid id)
+    {
+        var challenge = await db.AuthChallenges
+            .Include(e => e.Account)
+            .ThenInclude(e => e.Profile)
+            .FirstOrDefaultAsync(e => e.Id == id);
+
+        return challenge is null 
+            ? NotFound("Auth challenge was not found.") 
+            : challenge;
+    }
+
+    [HttpGet("challenge/{id:guid}/factors")]
+    public async Task<ActionResult<List<AccountAuthFactor>>> GetChallengeFactors([FromRoute] Guid id)
+    {
+        var challenge = await db.AuthChallenges
+            .Include(e => e.Account)
+            .Include(e => e.Account.AuthFactors)
+            .Where(e => e.Id == id)
+            .FirstOrDefaultAsync();
+        return challenge is null
+            ? NotFound("Auth challenge was not found.")
+            : challenge.Account.AuthFactors.Where(e => e is { EnabledAt: not null, Trustworthy: >= 1 }).ToList();
+    }
+
+    [HttpPost("challenge/{id:guid}/factors/{factorId:guid}")]
+    public async Task<ActionResult> RequestFactorCode(
+        [FromRoute] Guid id,
+        [FromRoute] Guid factorId,
+        [FromBody] string? hint
+    )
+    {
+        var challenge = await db.AuthChallenges
+            .Include(e => e.Account)
+            .Where(e => e.Id == id).FirstOrDefaultAsync();
+        if (challenge is null) return NotFound("Auth challenge was not found.");
+        var factor = await db.AccountAuthFactors
+            .Where(e => e.Id == factorId)
+            .Where(e => e.Account == challenge.Account).FirstOrDefaultAsync();
+        if (factor is null) return NotFound("Auth factor was not found.");
+
+        try
+        {
+            await accounts.SendFactorCode(challenge.Account, factor, hint);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest(ex.Message);
+        }
+
+        return Ok();
+    }
+
+    public class PerformChallengeRequest
+    {
+        [Required] public Guid FactorId { get; set; }
+        [Required] public string Password { get; set; } = string.Empty;
+    }
+
+    [HttpPatch("challenge/{id:guid}")]
+    public async Task<ActionResult<Challenge>> DoChallenge(
+        [FromRoute] Guid id,
+        [FromBody] PerformChallengeRequest request
+    )
+    {
+        var challenge = await db.AuthChallenges.Include(e => e.Account).FirstOrDefaultAsync(e => e.Id == id);
+        if (challenge is null) return NotFound("Auth challenge was not found.");
+
+        var factor = await db.AccountAuthFactors.FindAsync(request.FactorId);
+        if (factor is null) return NotFound("Auth factor was not found.");
+        if (factor.EnabledAt is null) return BadRequest("Auth factor is not enabled.");
+        if (factor.Trustworthy <= 0) return BadRequest("Auth factor is not trustworthy.");
+
+        if (challenge.StepRemain == 0) return challenge;
+        if (challenge.ExpiredAt.HasValue && challenge.ExpiredAt.Value < Instant.FromDateTimeUtc(DateTime.UtcNow))
+            return BadRequest();
+
+        try
+        {
+            if (await accounts.VerifyFactorCode(factor, request.Password))
+            {
+                challenge.StepRemain -= factor.Trustworthy;
+                challenge.StepRemain = Math.Max(0, challenge.StepRemain);
+                challenge.BlacklistFactors.Add(factor.Id);
+                db.Update(challenge);
+                
+            }
+            else
+            {
+                throw new ArgumentException("Invalid password.");
+            }
+        }
+        catch
+        {
+            challenge.FailedAttempts++;
+            db.Update(challenge);
+            
+            await db.SaveChangesAsync();
+            return BadRequest("Invalid password.");
+        }
+
+        if (challenge.StepRemain == 0)
+        {
+            
+        }
+
+        await db.SaveChangesAsync();
+        return challenge;
+    }
+
+    public class TokenExchangeRequest
+    {
+        public string GrantType { get; set; } = string.Empty;
+        public string? RefreshToken { get; set; }
+        public string? Code { get; set; }
+    }
+
+    public class TokenExchangeResponse
+    {
+        public string Token { get; set; } = string.Empty;
+    }
+
+    [HttpPost("token")]
+    public async Task<ActionResult<TokenExchangeResponse>> ExchangeToken([FromBody] TokenExchangeRequest request)
+    {
+        switch (request.GrantType)
+        {
+            case "authorization_code":
+                var code = Guid.TryParse(request.Code, out var codeId) ? codeId : Guid.Empty;
+                if (code == Guid.Empty)
+                    return BadRequest("Invalid or missing authorization code.");
+                var challenge = await db.AuthChallenges
+                    .Include(e => e.Account)
+                    .Where(e => e.Id == code)
+                    .FirstOrDefaultAsync();
+                if (challenge is null)
+                    return BadRequest("Authorization code not found or expired.");
+                if (challenge.StepRemain != 0)
+                    return BadRequest("Challenge not yet completed.");
+
+                var session = await db.AuthSessions
+                    .Where(e => e.Challenge == challenge)
+                    .FirstOrDefaultAsync();
+                if (session is not null)
+                    return BadRequest("Session already exists for this challenge.");
+
+                session = new Session
+                {
+                    LastGrantedAt = Instant.FromDateTimeUtc(DateTime.UtcNow),
+                    ExpiredAt = Instant.FromDateTimeUtc(DateTime.UtcNow.AddDays(30)),
+                    Account = challenge.Account,
+                    Challenge = challenge,
+                };
+
+                db.AuthSessions.Add(session);
+                await db.SaveChangesAsync();
+
+                var tk = auth.CreateToken(session);
+                return Ok(new TokenExchangeResponse { Token = tk });
+            case "refresh_token":
+            // Since we no longer need the refresh token
+            // This case is blank for now, thinking to mock it if the OIDC standard requires it
+            default:
+                return BadRequest("Unsupported grant type.");
+        }
+    }
+
+    [HttpPost("captcha")]
+    public async Task<ActionResult> ValidateCaptcha([FromBody] string token)
+    {
+        var result = await auth.ValidateCaptcha(token);
+        return result ? Ok() : BadRequest();
+    }
+}

DysonNetwork.Pass/Features/Auth/Interfaces/IAuthService.cs

@@ -0,0 +1,15 @@
+using DysonNetwork.Common.Models;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Auth.Interfaces;
+
+public interface IAuthService
+{
+    Task<int> DetectChallengeRisk(HttpRequest request, Common.Models.Account account);
+    Task<AuthSession> CreateSessionForOidcAsync(Common.Models.Account account, Instant time, Guid? customAppId = null);
+    Task<bool> ValidateCaptcha(string token);
+    string CreateToken(AuthSession session);
+    Task<bool> ValidateSudoMode(AuthSession session, string? pinCode);
+    Task<bool> ValidatePinCode(Guid accountId, string pinCode);
+    bool ValidateToken(string token, out Guid sessionId);
+}

DysonNetwork.Pass/Features/Auth/Services/Auth.cs

@@ -0,0 +1,272 @@
+using System.Security.Claims;
+using System.Security.Cryptography;
+using System.Text.Encodings.Web;
+using DysonNetwork.Pass.Features.Account;
+using DysonNetwork.Pass.Features.Auth.OidcProvider.Services;
+using DysonNetwork.Pass.Storage;
+using DysonNetwork.Pass.Storage.Handlers;
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.Extensions.Options;
+using SystemClock = NodaTime.SystemClock;
+
+namespace DysonNetwork.Pass.Features.Auth.Services;
+
+public static class AuthConstants
+{
+    public const string SchemeName = "DysonToken";
+    public const string TokenQueryParamName = "tk";
+    public const string CookieTokenName = "AuthToken";
+}
+
+public enum TokenType
+{
+    AuthKey,
+    ApiKey,
+    OidcKey,
+    Unknown
+}
+
+public class TokenInfo
+{
+    public string Token { get; set; } = string.Empty;
+    public TokenType Type { get; set; } = TokenType.Unknown;
+}
+
+public class DysonTokenAuthOptions : AuthenticationSchemeOptions;
+
+public class DysonTokenAuthHandler(
+    IOptionsMonitor<DysonTokenAuthOptions> options,
+    IConfiguration configuration,
+    ILoggerFactory logger,
+    UrlEncoder encoder,
+    PassDatabase database,
+    OidcProviderService oidc,
+    ICacheService cache,
+    FlushBufferService fbs
+)
+    : AuthenticationHandler<DysonTokenAuthOptions>(options, logger, encoder)
+{
+    public const string AuthCachePrefix = "auth:";
+
+    protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
+    {
+        var tokenInfo = _ExtractToken(Request);
+
+        if (tokenInfo == null || string.IsNullOrEmpty(tokenInfo.Token))
+            return AuthenticateResult.Fail("No token was provided.");
+
+        try
+        {
+            var now = SystemClock.Instance.GetCurrentInstant();
+
+            // Validate token and extract session ID
+            if (!ValidateToken(tokenInfo.Token, out var sessionId))
+                return AuthenticateResult.Fail("Invalid token.");
+
+            // Try to get session from cache first
+            var session = await cache.GetAsync<Session>($"{AuthCachePrefix}{sessionId}");
+
+            // If not in cache, load from database
+            if (session is null)
+            {
+                session = await database.AuthSessions
+                    .Where(e => e.Id == sessionId)
+                    .Include(e => e.Challenge)
+                    .Include(e => e.Account)
+                    .ThenInclude(e => e.Profile)
+                    .FirstOrDefaultAsync();
+
+                if (session is not null)
+                {
+                    // Store in cache for future requests
+                    await cache.SetWithGroupsAsync(
+                        $"auth:{sessionId}",
+                        session,
+                        [$"{AccountService.AccountCachePrefix}{session.Account.Id}"],
+                        TimeSpan.FromHours(1)
+                    );
+                }
+            }
+
+            // Check if the session exists
+            if (session == null)
+                return AuthenticateResult.Fail("Session not found.");
+
+            // Check if the session is expired
+            if (session.ExpiredAt.HasValue && session.ExpiredAt.Value < now)
+                return AuthenticateResult.Fail("Session expired.");
+
+            // Store user and session in the HttpContext.Items for easy access in controllers
+            Context.Items["CurrentUser"] = session.Account;
+            Context.Items["CurrentSession"] = session;
+            Context.Items["CurrentTokenType"] = tokenInfo.Type.ToString();
+
+            // Create claims from the session
+            var claims = new List<Claim>
+            {
+                new("user_id", session.Account.Id.ToString()),
+                new("session_id", session.Id.ToString()),
+                new("token_type", tokenInfo.Type.ToString())
+            };
+
+            // Add scopes as claims
+            session.Challenge.Scopes.ForEach(scope => claims.Add(new Claim("scope", scope)));
+
+            // Add superuser claim if applicable
+            if (session.Account.IsSuperuser)
+                claims.Add(new Claim("is_superuser", "1"));
+
+            // Create the identity and principal
+            var identity = new ClaimsIdentity(claims, AuthConstants.SchemeName);
+            var principal = new ClaimsPrincipal(identity);
+
+            var ticket = new AuthenticationTicket(principal, AuthConstants.SchemeName);
+
+            var lastInfo = new LastActiveInfo
+            {
+                Account = session.Account,
+                Session = session,
+                SeenAt = SystemClock.Instance.GetCurrentInstant(),
+            };
+            fbs.Enqueue(lastInfo);
+
+            return AuthenticateResult.Success(ticket);
+        }
+        catch (Exception ex)
+        {
+            return AuthenticateResult.Fail($"Authentication failed: {ex.Message}");
+        }
+    }
+
+    private bool ValidateToken(string token, out Guid sessionId)
+    {
+        sessionId = Guid.Empty;
+
+        try
+        {
+            var parts = token.Split('.');
+
+            switch (parts.Length)
+            {
+                // Handle JWT tokens (3 parts)
+                case 3:
+                {
+                    var (isValid, jwtResult) = oidc.ValidateToken(token);
+                    if (!isValid) return false;
+                    var jti = jwtResult?.Claims.FirstOrDefault(c => c.Type == "jti")?.Value;
+                    if (jti is null) return false;
+
+                    return Guid.TryParse(jti, out sessionId);
+                }
+                // Handle compact tokens (2 parts)
+                case 2:
+                    // Original compact token validation logic
+                    try
+                    {
+                        // Decode the payload
+                        var payloadBytes = Base64UrlDecode(parts[0]);
+
+                        // Extract session ID
+                        sessionId = new Guid(payloadBytes);
+
+                        // Load public key for verification
+                        var publicKeyPem = File.ReadAllText(configuration["AuthToken:PublicKeyPath"]!);
+                        using var rsa = RSA.Create();
+                        rsa.ImportFromPem(publicKeyPem);
+
+                        // Verify signature
+                        var signature = Base64UrlDecode(parts[1]);
+                        return rsa.VerifyData(payloadBytes, signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+                    }
+                    catch
+                    {
+                        return false;
+                    }
+
+                    break;
+                default:
+                    return false;
+            }
+        }
+        catch (Exception ex)
+        {
+            Logger.LogWarning(ex, "Token validation failed");
+            return false;
+        }
+    }
+
+    private static byte[] Base64UrlDecode(string base64Url)
+    {
+        var padded = base64Url
+            .Replace('-', '+')
+            .Replace('_', '/');
+
+        switch (padded.Length % 4)
+        {
+            case 2: padded += "=="; break;
+            case 3: padded += "="; break;
+        }
+
+        return Convert.FromBase64String(padded);
+    }
+
+    private TokenInfo? _ExtractToken(HttpRequest request)
+    {
+        // Check for token in query parameters
+        if (request.Query.TryGetValue(AuthConstants.TokenQueryParamName, out var queryToken))
+        {
+            return new TokenInfo
+            {
+                Token = queryToken.ToString(),
+                Type = TokenType.AuthKey
+            };
+        }
+
+
+        // Check for token in Authorization header
+        var authHeader = request.Headers.Authorization.ToString();
+        if (!string.IsNullOrEmpty(authHeader))
+        {
+            if (authHeader.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase))
+            {
+                var token = authHeader["Bearer ".Length..].Trim();
+                var parts = token.Split('.');
+                
+                return new TokenInfo
+                {
+                    Token = token,
+                    Type = parts.Length == 3 ? TokenType.OidcKey : TokenType.AuthKey
+                };
+            }
+            else if (authHeader.StartsWith("AtField ", StringComparison.OrdinalIgnoreCase))
+            {
+                return new TokenInfo
+                {
+                    Token = authHeader["AtField ".Length..].Trim(),
+                    Type = TokenType.AuthKey
+                };
+            }
+            else if (authHeader.StartsWith("AkField ", StringComparison.OrdinalIgnoreCase))
+            {
+                return new TokenInfo
+                {
+                    Token = authHeader["AkField ".Length..].Trim(),
+                    Type = TokenType.ApiKey
+                };
+            }
+        }
+
+        // Check for token in cookies
+        if (request.Cookies.TryGetValue(AuthConstants.CookieTokenName, out var cookieToken))
+        {
+            return new TokenInfo
+            {
+                Token = cookieToken,
+                Type = cookieToken.Count(c => c == '.') == 2 ? TokenType.OidcKey : TokenType.AuthKey
+            };
+        }
+
+
+        return null;
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/AuthService.cs

@@ -0,0 +1,320 @@
+using System.Security.Cryptography;
+using System.Text.Json;
+using DysonNetwork.Pass.Features.Account;
+using DysonNetwork.Pass.Storage;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+using DysonNetwork.Pass.Data;
+
+namespace DysonNetwork.Pass.Features.Auth;
+
+public class AuthService
+{
+    private readonly PassDatabase db;
+    private readonly IConfiguration config;
+    private readonly IHttpClientFactory httpClientFactory;
+    private readonly IHttpContextAccessor httpContextAccessor;
+    private readonly ICacheService cache;
+
+    public AuthService(
+        PassDatabase db,
+        IConfiguration config,
+        IHttpClientFactory httpClientFactory,
+        IHttpContextAccessor httpContextAccessor,
+        ICacheService cache
+    )
+    {
+        this.db = db;
+        this.config = config;
+        this.httpClientFactory = httpClientFactory;
+        this.httpContextAccessor = httpContextAccessor;
+        this.cache = cache;
+    }
+
+    private HttpContext HttpContext => httpContextAccessor.HttpContext!;
+
+    /// <summary>
+    /// Detect the risk of the current request to login
+    /// and returns the required steps to login.
+    /// </summary>
+    /// <param name="request">The request context</param>
+    /// <param name="account">The account to login</param>
+    /// <returns>The required steps to login</returns>
+    public async Task<int> DetectChallengeRisk(HttpRequest request, Models.Account account)
+    {
+        // 1) Find out how many authentication factors the account has enabled.
+        var maxSteps = await db.AccountAuthFactors
+            .Where(f => f.AccountId == account.Id)
+            .Where(f => f.EnabledAt != null)
+            .CountAsync();
+
+        // We’ll accumulate a “risk score” based on various factors.
+        // Then we can decide how many total steps are required for the challenge.
+        var riskScore = 0;
+
+        // 2) Get the remote IP address from the request (if any).
+        var ipAddress = request.HttpContext.Connection.RemoteIpAddress?.ToString();
+        var lastActiveInfo = await db.AuthSessions
+            .OrderByDescending(s => s.LastGrantedAt)
+            .Include(s => s.Challenge)
+            .Where(s => s.AccountId == account.Id)
+            .FirstOrDefaultAsync();
+
+        // Example check: if IP is missing or in an unusual range, increase the risk.
+        // (This is just a placeholder; in reality, you’d integrate with GeoIpService or a custom check.)
+        if (string.IsNullOrWhiteSpace(ipAddress))
+            riskScore += 1;
+        else
+        {
+            if (!string.IsNullOrEmpty(lastActiveInfo?.Challenge.IpAddress) &&
+                !lastActiveInfo.Challenge.IpAddress.Equals(ipAddress, StringComparison.OrdinalIgnoreCase))
+                riskScore += 1;
+        }
+
+        // 3) (Optional) Check how recent the last login was.
+        // If it was a long time ago, the risk might be higher.
+        var now = SystemClock.Instance.GetCurrentInstant();
+        var daysSinceLastActive = lastActiveInfo?.LastGrantedAt is not null
+            ? (now - lastActiveInfo.LastGrantedAt.Value).TotalDays
+            : double.MaxValue;
+        if (daysSinceLastActive > 30)
+            riskScore += 1;
+
+        // 4) Combine base “maxSteps” (the number of enabled factors) with any accumulated risk score.
+        const int totalRiskScore = 3;
+        var totalRequiredSteps = (int)Math.Round((float)maxSteps * riskScore / totalRiskScore);
+        // Clamp the steps
+        totalRequiredSteps = Math.Max(Math.Min(totalRequiredSteps, maxSteps), 1);
+
+        return totalRequiredSteps;
+    }
+
+    public async Task<Session> CreateSessionForOidcAsync(Models.Account account, Instant time, Guid? customAppId = null)
+    {
+        var challenge = new Challenge
+        {
+            AccountId = account.Id,
+            IpAddress = HttpContext.Connection.RemoteIpAddress?.ToString(),
+            UserAgent = HttpContext.Request.Headers.UserAgent,
+            StepRemain = 1,
+            StepTotal = 1,
+            Type = customAppId is not null ? ChallengeType.OAuth : ChallengeType.Oidc
+        };
+
+        var session = new Session
+        {
+            AccountId = account.Id,
+            CreatedAt = time,
+            LastGrantedAt = time,
+            Challenge = challenge,
+            AppId = customAppId
+        };
+
+        db.AuthChallenges.Add(challenge);
+        db.AuthSessions.Add(session);
+        await db.SaveChangesAsync();
+
+        return session;
+    }
+
+    public async Task<bool> ValidateCaptcha(string token)
+    {
+        if (string.IsNullOrWhiteSpace(token)) return false;
+
+        var provider = config.GetSection("Captcha")["Provider"]?.ToLower();
+        var apiSecret = config.GetSection("Captcha")["ApiSecret"];
+
+        var client = httpClientFactory.CreateClient();
+
+        var jsonOpts = new JsonSerializerOptions
+        {
+            PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower,
+            DictionaryKeyPolicy = JsonNamingPolicy.SnakeCaseLower
+        };
+
+        switch (provider)
+        {
+            case "cloudflare":
+                var content = new StringContent($"secret={apiSecret}&response={token}", System.Text.Encoding.UTF8,
+                    "application/x-www-form-urlencoded");
+                var response = await client.PostAsync("https://challenges.cloudflare.com/turnstile/v0/siteverify",
+                    content);
+                response.EnsureSuccessStatusCode();
+
+                var json = await response.Content.ReadAsStringAsync();
+                var result = JsonSerializer.Deserialize<CaptchaVerificationResponse>(json, options: jsonOpts);
+
+                return result?.Success == true;
+            case "google":
+                content = new StringContent($"secret={apiSecret}&response={token}", System.Text.Encoding.UTF8,
+                    "application/x-www-form-urlencoded");
+                response = await client.PostAsync("https://www.google.com/recaptcha/siteverify", content);
+                response.EnsureSuccessStatusCode();
+
+                json = await response.Content.ReadAsStringAsync();
+                result = JsonSerializer.Deserialize<CaptchaVerificationResponse>(json, options: jsonOpts);
+
+                return result?.Success == true;
+            case "hcaptcha":
+                content = new StringContent($"secret={apiSecret}&response={token}", System.Text.Encoding.UTF8,
+                    "application/x-www-form-urlencoded");
+                response = await client.PostAsync("https://hcaptcha.com/siteverify", content);
+                response.EnsureSuccessStatusCode();
+
+                json = await response.Content.ReadAsStringAsync();
+                result = JsonSerializer.Deserialize<CaptchaVerificationResponse>(json, options: jsonOpts);
+
+                return result?.Success == true;
+            default:
+                throw new ArgumentException("The server misconfigured for the captcha.");
+        }
+    }
+
+    public string CreateToken(Session session)
+    {
+        // Load the private key for signing
+        var privateKeyPem = File.ReadAllText(config["AuthToken:PrivateKeyPath"]!);
+        using var rsa = RSA.Create();
+        rsa.ImportFromPem(privateKeyPem);
+
+        // Create and return a single token
+        return CreateCompactToken(session.Id, rsa);
+    }
+
+    private string CreateCompactToken(Guid sessionId, RSA rsa)
+    {
+        // Create the payload: just the session ID
+        var payloadBytes = sessionId.ToByteArray();
+
+        // Base64Url encode the payload
+        var payloadBase64 = Base64UrlEncode(payloadBytes);
+
+        // Sign the payload with RSA-SHA256
+        var signature = rsa.SignData(payloadBytes, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+
+        // Base64Url encode the signature
+        var signatureBase64 = Base64UrlEncode(signature);
+
+        // Combine payload and signature with a dot
+        return $"{payloadBase64}.{signatureBase64}";
+    }
+
+    public async Task<bool> ValidateSudoMode(Session session, string? pinCode)
+    {
+        // Check if the session is already in sudo mode (cached)
+        var sudoModeKey = $"accounts:{session.Id}:sudo";
+        var (found, _) = await cache.GetAsyncWithStatus<bool>(sudoModeKey);
+        
+        if (found)
+        {
+            // Session is already in sudo mode
+            return true;
+        }
+        
+        // Check if the user has a pin code
+        var hasPinCode = await db.AccountAuthFactors
+            .Where(f => f.AccountId == session.AccountId)
+            .Where(f => f.EnabledAt != null)
+            .Where(f => f.Type == AccountAuthFactorType.PinCode)
+            .AnyAsync();
+            
+        if (!hasPinCode)
+        {
+            // User doesn't have a pin code, no validation needed
+            return true;
+        }
+        
+        // If pin code is not provided, we can't validate
+        if (string.IsNullOrEmpty(pinCode))
+        {
+            return false;
+        }
+        
+        try
+        {
+            // Validate the pin code
+            var isValid = await ValidatePinCode(session.AccountId, pinCode);
+            
+            if (isValid)
+            {
+                // Set session in sudo mode for 5 minutes
+                await cache.SetAsync(sudoModeKey, true, TimeSpan.FromMinutes(5));
+            }
+            
+            return isValid;
+        }
+        catch (InvalidOperationException)
+        {
+            // No pin code enabled for this account, so validation is successful
+            return true;
+        }
+    }
+
+    public async Task<bool> ValidatePinCode(Guid accountId, string pinCode)
+    {
+        var factor = await db.AccountAuthFactors
+            .Where(f => f.AccountId == accountId)
+            .Where(f => f.EnabledAt != null)
+            .Where(f => f.Type == AccountAuthFactorType.PinCode)
+            .FirstOrDefaultAsync();
+        if (factor is null) throw new InvalidOperationException("No pin code enabled for this account.");
+
+        return factor.VerifyPassword(pinCode);
+    }
+
+    public bool ValidateToken(string token, out Guid sessionId)
+    {
+        sessionId = Guid.Empty;
+
+        try
+        {
+            // Split the token
+            var parts = token.Split('.');
+            if (parts.Length != 2)
+                return false;
+
+            // Decode the payload
+            var payloadBytes = Base64UrlDecode(parts[0]);
+
+            // Extract session ID
+            sessionId = new Guid(payloadBytes);
+
+            // Load public key for verification
+            var publicKeyPem = File.ReadAllText(config["AuthToken:PublicKeyPath"]!);
+            using var rsa = RSA.Create();
+            rsa.ImportFromPem(publicKeyPem);
+
+            // Verify signature
+            var signature = Base64UrlDecode(parts[1]);
+            return rsa.VerifyData(payloadBytes, signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    // Helper methods for Base64Url encoding/decoding
+    private static string Base64UrlEncode(byte[] data)
+    {
+        return Convert.ToBase64String(data)
+            .TrimEnd('=')
+            .Replace('+', '-')
+            .Replace('/', '_');
+    }
+
+    private static byte[] Base64UrlDecode(string base64Url)
+    {
+        string padded = base64Url
+            .Replace('-', '+')
+            .Replace('_', '/');
+
+        switch (padded.Length % 4)
+        {
+            case 2: padded += "=="; break;
+            case 3: padded += "="; break;
+        }
+
+        return Convert.FromBase64String(padded);
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/CheckpointModel.cs

@@ -0,0 +1,6 @@
+namespace DysonNetwork.Pass.Features.Auth;
+
+public class CaptchaVerificationResponse
+{
+    public bool Success { get; set; }
+}

DysonNetwork.Pass/Features/Auth/Services/CompactTokenService.cs

@@ -0,0 +1,94 @@
+using System.Security.Cryptography;
+
+namespace DysonNetwork.Pass.Features.Auth;
+
+public class CompactTokenService(IConfiguration config)
+{
+    private readonly string _privateKeyPath = config["AuthToken:PrivateKeyPath"] 
+        ?? throw new InvalidOperationException("AuthToken:PrivateKeyPath configuration is missing");
+    
+    public string CreateToken(Session session)
+    {
+        // Load the private key for signing
+        var privateKeyPem = File.ReadAllText(_privateKeyPath);
+        using var rsa = RSA.Create();
+        rsa.ImportFromPem(privateKeyPem);
+        
+        // Create and return a single token
+        return CreateCompactToken(session.Id, rsa);
+    }
+
+    private string CreateCompactToken(Guid sessionId, RSA rsa)
+    {
+        // Create the payload: just the session ID
+        var payloadBytes = sessionId.ToByteArray();
+        
+        // Base64Url encode the payload
+        var payloadBase64 = Base64UrlEncode(payloadBytes);
+        
+        // Sign the payload with RSA-SHA256
+        var signature = rsa.SignData(payloadBytes, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+        
+        // Base64Url encode the signature
+        var signatureBase64 = Base64UrlEncode(signature);
+        
+        // Combine payload and signature with a dot
+        return $"{payloadBase64}.{signatureBase64}";
+    }
+    
+    public bool ValidateToken(string token, out Guid sessionId)
+    {
+        sessionId = Guid.Empty;
+        
+        try
+        {
+            // Split the token
+            var parts = token.Split('.');
+            if (parts.Length != 2)
+                return false;
+            
+            // Decode the payload
+            var payloadBytes = Base64UrlDecode(parts[0]);
+            
+            // Extract session ID
+            sessionId = new Guid(payloadBytes);
+            
+            // Load public key for verification
+            var publicKeyPem = File.ReadAllText(config["AuthToken:PublicKeyPath"]!);
+            using var rsa = RSA.Create();
+            rsa.ImportFromPem(publicKeyPem);
+            
+            // Verify signature
+            var signature = Base64UrlDecode(parts[1]);
+            return rsa.VerifyData(payloadBytes, signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+        }
+        catch
+        {
+            return false;
+        }
+    }
+    
+    // Helper methods for Base64Url encoding/decoding
+    private static string Base64UrlEncode(byte[] data)
+    {
+        return Convert.ToBase64String(data)
+            .TrimEnd('=')
+            .Replace('+', '-')
+            .Replace('/', '_');
+    }
+    
+    private static byte[] Base64UrlDecode(string base64Url)
+    {
+        string padded = base64Url
+            .Replace('-', '+')
+            .Replace('_', '/');
+            
+        switch (padded.Length % 4)
+        {
+            case 2: padded += "=="; break;
+            case 3: padded += "="; break;
+        }
+        
+        return Convert.FromBase64String(padded);
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OidcProvider/Controllers/OidcProviderController.cs

@@ -0,0 +1,243 @@
+using System.Security.Cryptography;
+using System.Text;
+using DysonNetwork.Pass.Features.Auth.OidcProvider.Options;
+using DysonNetwork.Pass.Features.Auth.OidcProvider.Responses;
+using DysonNetwork.Pass.Features.Auth.OidcProvider.Services;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Options;
+using System.Text.Json.Serialization;
+using DysonNetwork.Pass.Features.Account;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.IdentityModel.Tokens;
+using NodaTime;
+using DysonNetwork.Pass.Data;
+
+namespace DysonNetwork.Pass.Features.Auth.OidcProvider.Controllers;
+
+[Route("/auth/open")]
+[ApiController]
+public class OidcProviderController(
+    PassDatabase db,
+    OidcProviderService oidcService,
+    IConfiguration configuration,
+    IOptions<OidcProviderOptions> options,
+    ILogger<OidcProviderController> logger
+)
+    : ControllerBase
+{
+    [HttpPost("token")]
+    [Consumes("application/x-www-form-urlencoded")]
+    public async Task<IActionResult> Token([FromForm] TokenRequest request)
+    {
+        switch (request.GrantType)
+        {
+            // Validate client credentials
+            case "authorization_code" when request.ClientId == null || string.IsNullOrEmpty(request.ClientSecret):
+                return BadRequest("Client credentials are required");
+            case "authorization_code" when request.Code == null:
+                return BadRequest("Authorization code is required");
+            case "authorization_code":
+            {
+                var client = await oidcService.FindClientByIdAsync(request.ClientId.Value);
+                if (client == null ||
+                    !await oidcService.ValidateClientCredentialsAsync(request.ClientId.Value, request.ClientSecret))
+                    return BadRequest(new ErrorResponse
+                        { Error = "invalid_client", ErrorDescription = "Invalid client credentials" });
+
+                // Generate tokens
+                var tokenResponse = await oidcService.GenerateTokenResponseAsync(
+                    clientId: request.ClientId.Value,
+                    authorizationCode: request.Code!,
+                    redirectUri: request.RedirectUri,
+                    codeVerifier: request.CodeVerifier
+                );
+
+                return Ok(tokenResponse);
+            }
+            case "refresh_token" when string.IsNullOrEmpty(request.RefreshToken):
+                return BadRequest(new ErrorResponse
+                    { Error = "invalid_request", ErrorDescription = "Refresh token is required" });
+            case "refresh_token":
+            {
+                try
+                {
+                    // Decode the base64 refresh token to get the session ID
+                    var sessionIdBytes = Convert.FromBase64String(request.RefreshToken);
+                    var sessionId = new Guid(sessionIdBytes);
+
+                    // Find the session and related data
+                    var session = await oidcService.FindSessionByIdAsync(sessionId);
+                    var now = SystemClock.Instance.GetCurrentInstant();
+                    if (session?.App is null || session.ExpiredAt < now)
+                    {
+                        return BadRequest(new ErrorResponse
+                        {
+                            Error = "invalid_grant",
+                            ErrorDescription = "Invalid or expired refresh token"
+                        });
+                    }
+
+                    // Get the client
+                    var client = session.App;
+                    if (client == null)
+                    {
+                        return BadRequest(new ErrorResponse
+                        {
+                            Error = "invalid_client",
+                            ErrorDescription = "Client not found"
+                        });
+                    }
+
+                    // Generate new tokens
+                    var tokenResponse = await oidcService.GenerateTokenResponseAsync(
+                        clientId: session.AppId!.Value,
+                        sessionId: session.Id
+                    );
+
+                    return Ok(tokenResponse);
+                }
+                catch (FormatException)
+                {
+                    return BadRequest(new ErrorResponse
+                    {
+                        Error = "invalid_grant",
+                        ErrorDescription = "Invalid refresh token format"
+                    });
+                }
+            }
+            default:
+                return BadRequest(new ErrorResponse { Error = "unsupported_grant_type" });
+        }
+    }
+
+    [HttpGet("userinfo")]
+    [Authorize]
+    public async Task<IActionResult> GetUserInfo()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Pass.Models.Account currentUser ||
+            HttpContext.Items["CurrentSession"] is not Session currentSession) return Unauthorized();
+
+        // Get requested scopes from the token
+        var scopes = currentSession.Challenge.Scopes;
+
+        var userInfo = new Dictionary<string, object>
+        {
+            ["sub"] = currentUser.Id
+        };
+
+        // Include standard claims based on scopes
+        if (scopes.Contains("profile") || scopes.Contains("name"))
+        {
+            userInfo["name"] = currentUser.Name;
+            userInfo["preferred_username"] = currentUser.Nick;
+        }
+
+        var userEmail = await db.AccountContacts
+            .Where(c => c.Type == AccountContactType.Email && c.AccountId == currentUser.Id)
+            .FirstOrDefaultAsync();
+        if (scopes.Contains("email") && userEmail is not null)
+        {
+            userInfo["email"] = userEmail.Content;
+            userInfo["email_verified"] = userEmail.VerifiedAt is not null;
+        }
+
+        return Ok(userInfo);
+    }
+
+    [HttpGet("/.well-known/openid-configuration")]
+    public IActionResult GetConfiguration()
+    {
+        var baseUrl = configuration["BaseUrl"];
+        var issuer = options.Value.IssuerUri.TrimEnd('/');
+
+        return Ok(new
+        {
+            issuer = issuer,
+            authorization_endpoint = $"{baseUrl}/auth/authorize",
+            token_endpoint = $"{baseUrl}/auth/open/token",
+            userinfo_endpoint = $"{baseUrl}/auth/open/userinfo",
+            jwks_uri = $"{baseUrl}/.well-known/jwks",
+            scopes_supported = new[] { "openid", "profile", "email" },
+            response_types_supported = new[]
+                { "code", "token", "id_token", "code token", "code id_token", "token id_token", "code token id_token" },
+            grant_types_supported = new[] { "authorization_code", "refresh_token" },
+            token_endpoint_auth_methods_supported = new[] { "client_secret_basic", "client_secret_post" },
+            id_token_signing_alg_values_supported = new[] { "HS256" },
+            subject_types_supported = new[] { "public" },
+            claims_supported = new[] { "sub", "name", "email", "email_verified" },
+            code_challenge_methods_supported = new[] { "S256" },
+            response_modes_supported = new[] { "query", "fragment", "form_post" },
+            request_parameter_supported = true,
+            request_uri_parameter_supported = true,
+            require_request_uri_registration = false
+        });
+    }
+
+    [HttpGet("/.well-known/jwks")]
+    public IActionResult GetJwks()
+    {
+        using var rsa = options.Value.GetRsaPublicKey();
+        if (rsa == null)
+        {
+            return BadRequest("Public key is not configured");
+        }
+
+        var parameters = rsa.ExportParameters(false);
+        var keyId = Convert.ToBase64String(SHA256.HashData(parameters.Modulus!)[..8])
+            .Replace("+", "-")
+            .Replace("/", "_")
+            .Replace("=", "");
+
+        return Ok(new
+        {
+            keys = new[]
+            {
+                new
+                {
+                    kty = "RSA",
+                    use = "sig",
+                    kid = keyId,
+                    n = Base64UrlEncoder.Encode(parameters.Modulus!),
+                    e = Base64UrlEncoder.Encode(parameters.Exponent!),
+                    alg = "RS256"
+                }
+            }
+        });
+    }
+}
+
+public class TokenRequest
+{
+    [JsonPropertyName("grant_type")]
+    [FromForm(Name = "grant_type")]
+    public string? GrantType { get; set; }
+
+    [JsonPropertyName("code")]
+    [FromForm(Name = "code")]
+    public string? Code { get; set; }
+
+    [JsonPropertyName("redirect_uri")]
+    [FromForm(Name = "redirect_uri")]
+    public string? RedirectUri { get; set; }
+
+    [JsonPropertyName("client_id")]
+    [FromForm(Name = "client_id")]
+    public Guid? ClientId { get; set; }
+
+    [JsonPropertyName("client_secret")]
+    [FromForm(Name = "client_secret")]
+    public string? ClientSecret { get; set; }
+
+    [JsonPropertyName("refresh_token")]
+    [FromForm(Name = "refresh_token")]
+    public string? RefreshToken { get; set; }
+
+    [JsonPropertyName("scope")]
+    [FromForm(Name = "scope")]
+    public string? Scope { get; set; }
+
+    [JsonPropertyName("code_verifier")]
+    [FromForm(Name = "code_verifier")]
+    public string? CodeVerifier { get; set; }
+}

DysonNetwork.Pass/Features/Auth/Services/OidcProvider/Models/AuthorizationCodeInfo.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Auth.OidcProvider.Models;
+
+public class AuthorizationCodeInfo
+{
+    public Guid ClientId { get; set; }
+    public Guid AccountId { get; set; }
+    public string RedirectUri { get; set; } = string.Empty;
+    public List<string> Scopes { get; set; } = new();
+    public string? CodeChallenge { get; set; }
+    public string? CodeChallengeMethod { get; set; }
+    public string? Nonce { get; set; }
+    public Instant CreatedAt { get; set; }
+}

DysonNetwork.Pass/Features/Auth/Services/OidcProvider/Options/OidcProviderOptions.cs

@@ -0,0 +1,36 @@
+using System.Security.Cryptography;
+
+namespace DysonNetwork.Pass.Features.Auth.OidcProvider.Options;
+
+public class OidcProviderOptions
+{
+    public string IssuerUri { get; set; } = "https://your-issuer-uri.com";
+    public string? PublicKeyPath { get; set; }
+    public string? PrivateKeyPath { get; set; }
+    public TimeSpan AccessTokenLifetime { get; set; } = TimeSpan.FromHours(1);
+    public TimeSpan RefreshTokenLifetime { get; set; } = TimeSpan.FromDays(30);
+    public TimeSpan AuthorizationCodeLifetime { get; set; } = TimeSpan.FromMinutes(5);
+    public bool RequireHttpsMetadata { get; set; } = true;
+
+    public RSA? GetRsaPrivateKey()
+    {
+        if (string.IsNullOrEmpty(PrivateKeyPath) || !File.Exists(PrivateKeyPath))
+            return null;
+
+        var privateKey = File.ReadAllText(PrivateKeyPath);
+        var rsa = RSA.Create();
+        rsa.ImportFromPem(privateKey.AsSpan());
+        return rsa;
+    }
+
+    public RSA? GetRsaPublicKey()
+    {
+        if (string.IsNullOrEmpty(PublicKeyPath) || !File.Exists(PublicKeyPath))
+            return null;
+
+        var publicKey = File.ReadAllText(PublicKeyPath);
+        var rsa = RSA.Create();
+        rsa.ImportFromPem(publicKey.AsSpan());
+        return rsa;
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OidcProvider/Responses/AuthorizationResponse.cs

@@ -0,0 +1,23 @@
+using System.Text.Json.Serialization;
+
+namespace DysonNetwork.Pass.Features.Auth.OidcProvider.Responses;
+
+public class AuthorizationResponse
+{
+    [JsonPropertyName("code")]
+    public string Code { get; set; } = null!;
+
+    [JsonPropertyName("state")]
+    public string? State { get; set; }
+
+    [JsonPropertyName("scope")]
+    public string? Scope { get; set; }
+
+
+    [JsonPropertyName("session_state")]
+    public string? SessionState { get; set; }
+
+
+    [JsonPropertyName("iss")]
+    public string? Issuer { get; set; }
+}

DysonNetwork.Pass/Features/Auth/Services/OidcProvider/Responses/ErrorResponse.cs

@@ -0,0 +1,20 @@
+using System.Text.Json.Serialization;
+
+namespace DysonNetwork.Pass.Features.Auth.OidcProvider.Responses;
+
+public class ErrorResponse
+{
+    [JsonPropertyName("error")]
+    public string Error { get; set; } = null!;
+
+    [JsonPropertyName("error_description")]
+    public string? ErrorDescription { get; set; }
+
+
+    [JsonPropertyName("error_uri")]
+    public string? ErrorUri { get; set; }
+
+
+    [JsonPropertyName("state")]
+    public string? State { get; set; }
+}

DysonNetwork.Pass/Features/Auth/Services/OidcProvider/Responses/TokenResponse.cs

@@ -0,0 +1,26 @@
+using System.Text.Json.Serialization;
+
+namespace DysonNetwork.Pass.Features.Auth.OidcProvider.Responses;
+
+public class TokenResponse
+{
+    [JsonPropertyName("access_token")]
+    public string AccessToken { get; set; } = null!;
+
+    [JsonPropertyName("expires_in")]
+    public int ExpiresIn { get; set; }
+
+    [JsonPropertyName("token_type")]
+    public string TokenType { get; set; } = "Bearer";
+
+    [JsonPropertyName("refresh_token")]
+    public string? RefreshToken { get; set; }
+
+
+    [JsonPropertyName("scope")]
+    public string? Scope { get; set; }
+
+
+    [JsonPropertyName("id_token")]
+    public string? IdToken { get; set; }
+}

DysonNetwork.Pass/Features/Auth/Services/OidcProvider/Services/OidcProviderService.cs

@@ -0,0 +1,392 @@
+using DysonNetwork.Pass.Features.Auth.OidcProvider.Models;
+using DysonNetwork.Pass.Features.Auth.OidcProvider.Options;
+using DysonNetwork.Pass.Features.Auth.OidcProvider.Responses;
+using DysonNetwork.Pass.Developer;
+using DysonNetwork.Pass.Storage;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
+using Microsoft.IdentityModel.Tokens;
+using NodaTime;
+using DysonNetwork.Pass.Data;
+
+namespace DysonNetwork.Pass.Features.Auth.OidcProvider.Services;
+
+public class OidcProviderService(
+    PassDatabase db,
+    AuthService auth,
+    ICacheService cache,
+    IOptions<OidcProviderOptions> options,
+    ILogger<OidcProviderService> logger
+)
+{
+    private readonly OidcProviderOptions _options = options.Value;
+
+    public async Task<CustomApp?> FindClientByIdAsync(Guid clientId)
+    {
+        return await db.CustomApps
+            .Include(c => c.Secrets)
+            .FirstOrDefaultAsync(c => c.Id == clientId);
+    }
+
+    public async Task<CustomApp?> FindClientByAppIdAsync(Guid appId)
+    {
+        return await db.CustomApps
+            .Include(c => c.Secrets)
+            .FirstOrDefaultAsync(c => c.Id == appId);
+    }
+
+    public async Task<Session?> FindValidSessionAsync(Guid accountId, Guid clientId)
+    {
+        var now = SystemClock.Instance.GetCurrentInstant();
+
+        return await db.AuthSessions
+            .Include(s => s.Challenge)
+            .Where(s => s.AccountId == accountId &&
+                        s.AppId == clientId &&
+                        (s.ExpiredAt == null || s.ExpiredAt > now) &&
+                        s.Challenge.Type == ChallengeType.OAuth)
+            .OrderByDescending(s => s.CreatedAt)
+            .FirstOrDefaultAsync();
+    }
+
+    public async Task<bool> ValidateClientCredentialsAsync(Guid clientId, string clientSecret)
+    {
+        var client = await FindClientByIdAsync(clientId);
+        if (client == null) return false;
+
+        var clock = SystemClock.Instance;
+        var secret = client.Secrets
+            .Where(s => s.IsOidc && (s.ExpiredAt == null || s.ExpiredAt > clock.GetCurrentInstant()))
+            .FirstOrDefault(s => s.Secret == clientSecret); // In production, use proper hashing
+
+        return secret != null;
+    }
+
+    public async Task<TokenResponse> GenerateTokenResponseAsync(
+        Guid clientId,
+        string? authorizationCode = null,
+        string? redirectUri = null,
+        string? codeVerifier = null,
+        Guid? sessionId = null
+    )
+    {
+        var client = await FindClientByIdAsync(clientId);
+        if (client == null)
+            throw new InvalidOperationException("Client not found");
+
+        Session session;
+        var clock = SystemClock.Instance;
+        var now = clock.GetCurrentInstant();
+
+        List<string>? scopes = null;
+        if (authorizationCode != null)
+        {
+            // Authorization code flow
+            var authCode = await ValidateAuthorizationCodeAsync(authorizationCode, clientId, redirectUri, codeVerifier);
+            if (authCode is null) throw new InvalidOperationException("Invalid authorization code");
+            var account = await db.Accounts.Where(a => a.Id == authCode.AccountId).FirstOrDefaultAsync();
+            if (account is null) throw new InvalidOperationException("Account was not found");
+
+            session = await auth.CreateSessionForOidcAsync(account, now, client.Id);
+            scopes = authCode.Scopes;
+        }
+        else if (sessionId.HasValue)
+        {
+            // Refresh token flow
+            session = await FindSessionByIdAsync(sessionId.Value) ??
+                      throw new InvalidOperationException("Invalid session");
+
+            // Verify the session is still valid
+            if (session.ExpiredAt < now)
+                throw new InvalidOperationException("Session has expired");
+        }
+        else
+        {
+            throw new InvalidOperationException("Either authorization code or session ID must be provided");
+        }
+
+        var expiresIn = (int)_options.AccessTokenLifetime.TotalSeconds;
+        var expiresAt = now.Plus(Duration.FromSeconds(expiresIn));
+
+        // Generate an access token
+        var accessToken = GenerateJwtToken(client, session, expiresAt, scopes);
+        var refreshToken = GenerateRefreshToken(session);
+
+        return new TokenResponse
+        {
+            AccessToken = accessToken,
+            ExpiresIn = expiresIn,
+            TokenType = "Bearer",
+            RefreshToken = refreshToken,
+            Scope = scopes != null ? string.Join(" ", scopes) : null
+        };
+    }
+
+    private string GenerateJwtToken(
+        CustomApp client,
+        Session session,
+        Instant expiresAt,
+        IEnumerable<string>? scopes = null
+    )
+    {
+        var tokenHandler = new JwtSecurityTokenHandler();
+        var clock = SystemClock.Instance;
+        var now = clock.GetCurrentInstant();
+
+        var tokenDescriptor = new SecurityTokenDescriptor
+        {
+            Subject = new ClaimsIdentity([
+                new Claim(JwtRegisteredClaimNames.Sub, session.AccountId.ToString()),
+                new Claim(JwtRegisteredClaimNames.Jti, session.Id.ToString()),
+                new Claim(JwtRegisteredClaimNames.Iat, now.ToUnixTimeSeconds().ToString(),
+                    ClaimValueTypes.Integer64),
+                new Claim("client_id", client.Id.ToString())
+            ]),
+            Expires = expiresAt.ToDateTimeUtc(),
+            Issuer = _options.IssuerUri,
+            Audience = client.Id.ToString()
+        };
+
+        // Try to use RSA signing if keys are available, fall back to HMAC
+        var rsaPrivateKey = _options.GetRsaPrivateKey();
+        tokenDescriptor.SigningCredentials = new SigningCredentials(
+            new RsaSecurityKey(rsaPrivateKey),
+            SecurityAlgorithms.RsaSha256
+        );
+
+        // Add scopes as claims if provided
+        var effectiveScopes = scopes?.ToList() ?? client.OauthConfig!.AllowedScopes?.ToList() ?? [];
+        if (effectiveScopes.Count != 0)
+        {
+            tokenDescriptor.Subject.AddClaims(
+                effectiveScopes.Select(scope => new Claim("scope", scope)));
+        }
+
+        var token = tokenHandler.CreateToken(tokenDescriptor);
+        return tokenHandler.WriteToken(token);
+    }
+
+    public (bool isValid, JwtSecurityToken? token) ValidateToken(string token)
+    {
+        try
+        {
+            var tokenHandler = new JwtSecurityTokenHandler();
+            var validationParameters = new TokenValidationParameters
+            {
+                ValidateIssuer = true,
+                ValidIssuer = _options.IssuerUri,
+                ValidateAudience = false,
+                ValidateLifetime = true,
+                ClockSkew = TimeSpan.Zero
+            };
+
+            // Try to use RSA validation if public key is available
+            var rsaPublicKey = _options.GetRsaPublicKey();
+            validationParameters.IssuerSigningKey = new RsaSecurityKey(rsaPublicKey);
+            validationParameters.ValidateIssuerSigningKey = true;
+            validationParameters.ValidAlgorithms = new[] { SecurityAlgorithms.RsaSha256 };
+
+
+            tokenHandler.ValidateToken(token, validationParameters, out var validatedToken);
+            return (true, (JwtSecurityToken)validatedToken);
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Token validation failed");
+            return (false, null);
+        }
+    }
+
+    public async Task<Session?> FindSessionByIdAsync(Guid sessionId)
+    {
+        return await db.AuthSessions
+            .Include(s => s.Account)
+            .Include(s => s.Challenge)
+            .Include(s => s.App)
+            .FirstOrDefaultAsync(s => s.Id == sessionId);
+    }
+
+    private static string GenerateRefreshToken(Session session)
+    {
+        return Convert.ToBase64String(session.Id.ToByteArray());
+    }
+
+    private static bool VerifyHashedSecret(string secret, string hashedSecret)
+    {
+        // In a real implementation, you'd use a proper password hashing algorithm like PBKDF2, bcrypt, or Argon2
+        // For now, we'll do a simple comparison, but you should replace this with proper hashing
+        return string.Equals(secret, hashedSecret, StringComparison.Ordinal);
+    }
+
+    public async Task<string> GenerateAuthorizationCodeForReuseSessionAsync(
+        Session session,
+        Guid clientId,
+        string redirectUri,
+        IEnumerable<string> scopes,
+        string? codeChallenge = null,
+        string? codeChallengeMethod = null,
+        string? nonce = null)
+    {
+        var clock = SystemClock.Instance;
+        var now = clock.GetCurrentInstant();
+        var code = Guid.NewGuid().ToString("N");
+
+        // Update the session's last activity time
+        await db.AuthSessions.Where(s => s.Id == session.Id)
+            .ExecuteUpdateAsync(s => s.SetProperty(s => s.LastGrantedAt, now));
+
+        // Create the authorization code info
+        var authCodeInfo = new AuthorizationCodeInfo
+        {
+            ClientId = clientId,
+            AccountId = session.AccountId,
+            RedirectUri = redirectUri,
+            Scopes = scopes.ToList(),
+            CodeChallenge = codeChallenge,
+            CodeChallengeMethod = codeChallengeMethod,
+            Nonce = nonce,
+            CreatedAt = now
+        };
+        
+        // Store the code with its metadata in the cache
+        var cacheKey = $"auth:code:{code}";
+        await cache.SetAsync(cacheKey, authCodeInfo, _options.AuthorizationCodeLifetime);
+
+        logger.LogInformation("Generated authorization code for client {ClientId} and user {UserId}", clientId, session.AccountId);
+        return code;
+    }
+
+    public async Task<string> GenerateAuthorizationCodeAsync(
+        Guid clientId,
+        Guid userId,
+        string redirectUri,
+        IEnumerable<string> scopes,
+        string? codeChallenge = null,
+        string? codeChallengeMethod = null,
+        string? nonce = null
+    )
+    {
+        // Generate a random code
+        var clock = SystemClock.Instance;
+        var code = GenerateRandomString(32);
+        var now = clock.GetCurrentInstant();
+
+        // Create the authorization code info
+        var authCodeInfo = new AuthorizationCodeInfo
+        {
+            ClientId = clientId,
+            AccountId = userId,
+            RedirectUri = redirectUri,
+            Scopes = scopes.ToList(),
+            CodeChallenge = codeChallenge,
+            CodeChallengeMethod = codeChallengeMethod,
+            Nonce = nonce,
+            CreatedAt = now
+        };
+
+        // Store the code with its metadata in the cache
+        var cacheKey = $"auth:code:{code}";
+        await cache.SetAsync(cacheKey, authCodeInfo, _options.AuthorizationCodeLifetime);
+
+        logger.LogInformation("Generated authorization code for client {ClientId} and user {UserId}", clientId, userId);
+        return code;
+    }
+
+    private async Task<AuthorizationCodeInfo?> ValidateAuthorizationCodeAsync(
+        string code,
+        Guid clientId,
+        string? redirectUri = null,
+        string? codeVerifier = null
+    )
+    {
+        var cacheKey = $"auth:code:{code}";
+        var (found, authCode) = await cache.GetAsyncWithStatus<AuthorizationCodeInfo>(cacheKey);
+
+        if (!found || authCode == null)
+        {
+            logger.LogWarning("Authorization code not found: {Code}", code);
+            return null;
+        }
+
+        // Verify client ID matches
+        if (authCode.ClientId != clientId)
+        {
+            logger.LogWarning(
+                "Client ID mismatch for code {Code}. Expected: {ExpectedClientId}, Actual: {ActualClientId}",
+                code, authCode.ClientId, clientId);
+            return null;
+        }
+
+        // Verify redirect URI if provided
+        if (!string.IsNullOrEmpty(redirectUri) && authCode.RedirectUri != redirectUri)
+        {
+            logger.LogWarning("Redirect URI mismatch for code {Code}", code);
+            return null;
+        }
+
+        // Verify PKCE code challenge if one was provided during authorization
+        if (!string.IsNullOrEmpty(authCode.CodeChallenge))
+        {
+            if (string.IsNullOrEmpty(codeVerifier))
+            {
+                logger.LogWarning("PKCE code verifier is required but not provided for code {Code}", code);
+                return null;
+            }
+
+            var isValid = authCode.CodeChallengeMethod?.ToUpperInvariant() switch
+            {
+                "S256" => VerifyCodeChallenge(codeVerifier, authCode.CodeChallenge, "S256"),
+                "PLAIN" => VerifyCodeChallenge(codeVerifier, authCode.CodeChallenge, "PLAIN"),
+                _ => false // Unsupported code challenge method
+            };
+
+            if (!isValid)
+            {
+                logger.LogWarning("PKCE code verifier validation failed for code {Code}", code);
+                return null;
+            }
+        }
+
+        // Code is valid, remove it from the cache (codes are single-use)
+        await cache.RemoveAsync(cacheKey);
+
+        return authCode;
+    }
+
+    private static string GenerateRandomString(int length)
+    {
+        const string chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._~";
+        var random = RandomNumberGenerator.Create();
+        var result = new char[length];
+
+        for (int i = 0; i < length; i++)
+        {
+            var randomNumber = new byte[4];
+            random.GetBytes(randomNumber);
+            var index = (int)(BitConverter.ToUInt32(randomNumber, 0) % chars.Length);
+            result[i] = chars[index];
+        }
+
+        return new string(result);
+    }
+
+    private static bool VerifyCodeChallenge(string codeVerifier, string codeChallenge, string method)
+    {
+        if (string.IsNullOrEmpty(codeVerifier)) return false;
+
+        if (method == "S256")
+        {
+            using var sha256 = SHA256.Create();
+            var hash = sha256.ComputeHash(Encoding.UTF8.GetBytes(codeVerifier));
+            var base64 = Base64UrlEncoder.Encode(hash);
+            return string.Equals(base64, codeChallenge, StringComparison.Ordinal);
+        }
+
+        if (method == "PLAIN")
+        {
+            return string.Equals(codeVerifier, codeChallenge, StringComparison.Ordinal);
+        }
+
+        return false;
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/AfdianOidcService.cs

@@ -0,0 +1,95 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+using DysonNetwork.Pass.Storage;
+using DysonNetwork.Pass.Data;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+public class AfdianOidcService(
+    IConfiguration configuration,
+    IHttpClientFactory httpClientFactory,
+    PassDatabase db,
+    AuthService auth,
+    ICacheService cache,
+    ILogger<AfdianOidcService> logger
+)
+    : OidcService(configuration, httpClientFactory, db, auth, cache)
+{
+    public override string ProviderName => "Afdian";
+    protected override string DiscoveryEndpoint => ""; // Afdian doesn't have a standard OIDC discovery endpoint
+    protected override string ConfigSectionName => "Afdian";
+
+    public override string GetAuthorizationUrl(string state, string nonce)
+    {
+        var config = GetProviderConfig();
+        var queryParams = new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "redirect_uri", config.RedirectUri },
+            { "response_type", "code" },
+            { "scope", "basic" },
+            { "state", state },
+        };
+
+        var queryString = string.Join("&", queryParams.Select(p => $"{p.Key}={Uri.EscapeDataString(p.Value)}"));
+        return $"https://afdian.com/oauth2/authorize?{queryString}";
+    }
+
+    protected override Task<OidcDiscoveryDocument?> GetDiscoveryDocumentAsync()
+    {
+        return Task.FromResult(new OidcDiscoveryDocument
+        {
+            AuthorizationEndpoint = "https://afdian.com/oauth2/authorize",
+            TokenEndpoint = "https://afdian.com/oauth2/access_token",
+            UserinfoEndpoint = null,
+            JwksUri = null
+        })!;
+    }
+
+    public override async Task<OidcUserInfo> ProcessCallbackAsync(OidcCallbackData callbackData)
+    {
+        try
+        {
+            var config = GetProviderConfig();
+            var content = new FormUrlEncodedContent(new Dictionary<string, string>
+            {
+                { "client_id", config.ClientId },
+                { "client_secret", config.ClientSecret },
+                { "grant_type", "authorization_code" },
+                { "code", callbackData.Code },
+                { "redirect_uri", config.RedirectUri },
+            });
+
+            var client = HttpClientFactory.CreateClient();
+            var request = new HttpRequestMessage(HttpMethod.Post, "https://afdian.com/oauth2/access_token");
+            request.Content = content;
+            
+            var response = await client.SendAsync(request);
+            response.EnsureSuccessStatusCode();
+            
+            var json = await response.Content.ReadAsStringAsync();
+            logger.LogInformation("Trying get userinfo from afdian, response: {Response}", json);
+            var afdianResponse = JsonDocument.Parse(json).RootElement;
+
+            var user = afdianResponse.TryGetProperty("data", out var dataElement) ? dataElement : default;
+            var userId = user.TryGetProperty("user_id", out var userIdElement) ? userIdElement.GetString() ?? "" : "";
+            var avatar = user.TryGetProperty("avatar", out var avatarElement) ? avatarElement.GetString() : null;
+
+            return new OidcUserInfo
+            {
+                UserId = userId,
+                DisplayName = (user.TryGetProperty("name", out var nameElement)
+                    ? nameElement.GetString()
+                    : null) ?? "",
+                ProfilePictureUrl = avatar,
+                Provider = ProviderName
+            };
+        }
+        catch (Exception ex)
+        {
+            // Due to afidan's API isn't compliant with OAuth2, we want more logs from it to investigate.
+            logger.LogError(ex, "Failed to get user info from Afdian");
+            throw;
+        }
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/AppleMobileSignInRequest.cs

@@ -0,0 +1,19 @@
+
+using System.ComponentModel.DataAnnotations;
+using System.Text.Json.Serialization;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+public class AppleMobileConnectRequest
+{
+    [Required]
+    public required string IdentityToken { get; set; }
+    [Required]
+    public required string AuthorizationCode { get; set; }
+}
+
+public class AppleMobileSignInRequest : AppleMobileConnectRequest
+{
+    [Required]
+    public required string DeviceId { get; set; }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/AppleOidcService.cs

@@ -0,0 +1,279 @@
+using System.IdentityModel.Tokens.Jwt;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using DysonNetwork.Common.Services;
+using Microsoft.IdentityModel.Tokens;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+/// <summary>
+/// Implementation of OpenID Connect service for Apple Sign In
+/// </summary>
+public class AppleOidcService(
+    IConfiguration configuration,
+    IHttpClientFactory httpClientFactory,
+    PassDatabase db,
+    AuthService auth,
+    ICacheService cache
+)
+    : OidcService(configuration, httpClientFactory, db, auth, cache)
+{
+    private readonly IConfiguration _configuration = configuration;
+    private readonly IHttpClientFactory _httpClientFactory = httpClientFactory;
+
+    public override string ProviderName => "apple";
+    protected override string DiscoveryEndpoint => "https://appleid.apple.com/.well-known/openid-configuration";
+    protected override string ConfigSectionName => "Apple";
+
+    public override string GetAuthorizationUrl(string state, string nonce)
+    {
+        var config = GetProviderConfig();
+
+        var queryParams = new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "redirect_uri", config.RedirectUri },
+            { "response_type", "code id_token" },
+            { "scope", "name email" },
+            { "response_mode", "form_post" },
+            { "state", state },
+            { "nonce", nonce }
+        };
+
+        var queryString = string.Join("&", queryParams.Select(p => $"{p.Key}={Uri.EscapeDataString(p.Value)}"));
+        return $"https://appleid.apple.com/auth/authorize?{queryString}";
+    }
+
+    public override async Task<OidcUserInfo> ProcessCallbackAsync(OidcCallbackData callbackData)
+    {
+        // Verify and decode the id_token
+        var userInfo = await ValidateTokenAsync(callbackData.IdToken);
+
+        // If user data is provided in first login, parse it
+        if (!string.IsNullOrEmpty(callbackData.RawData))
+        {
+            var userData = JsonSerializer.Deserialize<AppleUserData>(callbackData.RawData);
+            if (userData?.Name != null)
+            {
+                userInfo.FirstName = userData.Name.FirstName ?? "";
+                userInfo.LastName = userData.Name.LastName ?? "";
+                userInfo.DisplayName = $"{userInfo.FirstName} {userInfo.LastName}".Trim();
+            }
+        }
+
+        // Exchange authorization code for access token (optional, if you need the access token)
+        if (string.IsNullOrEmpty(callbackData.Code)) return userInfo;
+        var tokenResponse = await ExchangeCodeForTokensAsync(callbackData.Code);
+        if (tokenResponse == null) return userInfo;
+        userInfo.AccessToken = tokenResponse.AccessToken;
+        userInfo.RefreshToken = tokenResponse.RefreshToken;
+
+        return userInfo;
+    }
+
+    private async Task<OidcUserInfo> ValidateTokenAsync(string idToken)
+    {
+        // Get Apple's public keys
+        var jwksJson = await GetAppleJwksAsync();
+        var jwks = JsonSerializer.Deserialize<AppleJwks>(jwksJson) ?? new AppleJwks { Keys = new List<AppleKey>() };
+
+        // Parse the JWT header to get the key ID
+        var handler = new JwtSecurityTokenHandler();
+        var jwtToken = handler.ReadJwtToken(idToken);
+        var kid = jwtToken.Header.Kid;
+
+        // Find the matching key
+        var key = jwks.Keys.FirstOrDefault(k => k.Kid == kid);
+        if (key == null)
+        {
+            throw new SecurityTokenValidationException("Unable to find matching key in Apple's JWKS");
+        }
+
+        // Create the validation parameters
+        var validationParameters = new TokenValidationParameters
+        {
+            ValidateIssuer = true,
+            ValidIssuer = "https://appleid.apple.com",
+            ValidateAudience = true,
+            ValidAudience = GetProviderConfig().ClientId,
+            ValidateLifetime = true,
+            IssuerSigningKey = key.ToSecurityKey()
+        };
+
+        return ValidateAndExtractIdToken(idToken, validationParameters);
+    }
+
+    protected override Dictionary<string, string> BuildTokenRequestParameters(
+        string code,
+        ProviderConfiguration config,
+        string? codeVerifier
+    )
+    {
+        var parameters = new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "client_secret", GenerateClientSecret() },
+            { "code", code },
+            { "grant_type", "authorization_code" },
+            { "redirect_uri", config.RedirectUri }
+        };
+
+        return parameters;
+    }
+
+    private async Task<string> GetAppleJwksAsync()
+    {
+        var client = _httpClientFactory.CreateClient();
+        var response = await client.GetAsync("https://appleid.apple.com/auth/keys");
+        response.EnsureSuccessStatusCode();
+
+        return await response.Content.ReadAsStringAsync();
+    }
+
+    /// <summary>
+    /// Generates a client secret for Apple Sign In using JWT
+    /// </summary>
+    private string GenerateClientSecret()
+    {
+        var now = DateTime.UtcNow;
+        var teamId = _configuration["Oidc:Apple:TeamId"];
+        var clientId = _configuration["Oidc:Apple:ClientId"];
+        var keyId = _configuration["Oidc:Apple:KeyId"];
+        var privateKeyPath = _configuration["Oidc:Apple:PrivateKeyPath"];
+
+        if (string.IsNullOrEmpty(teamId) || string.IsNullOrEmpty(clientId) || string.IsNullOrEmpty(keyId) ||
+            string.IsNullOrEmpty(privateKeyPath))
+        {
+            throw new InvalidOperationException("Apple OIDC configuration is missing required values (TeamId, ClientId, KeyId, PrivateKeyPath).");
+        }
+        
+        // Read the private key
+        var privateKey = File.ReadAllText(privateKeyPath);
+
+        // Create the JWT header
+        var header = new Dictionary<string, object>
+        {
+            { "alg", "ES256" },
+            { "kid", keyId }
+        };
+
+        // Create the JWT payload
+        var payload = new Dictionary<string, object>
+        {
+            { "iss", teamId },
+            { "iat", ToUnixTimeSeconds(now) },
+            { "exp", ToUnixTimeSeconds(now.AddMinutes(5)) },
+            { "aud", "https://appleid.apple.com" },
+            { "sub", clientId }
+        };
+
+        // Convert header and payload to Base64Url
+        var headerJson = JsonSerializer.Serialize(header);
+        var payloadJson = JsonSerializer.Serialize(payload);
+        var headerBase64 = Base64UrlEncode(Encoding.UTF8.GetBytes(headerJson));
+        var payloadBase64 = Base64UrlEncode(Encoding.UTF8.GetBytes(payloadJson));
+
+        // Create the signature
+        var dataToSign = $"{headerBase64}.{payloadBase64}";
+        var signature = SignWithECDsa(dataToSign, privateKey);
+
+        // Combine all parts
+        return $"{headerBase64}.{payloadBase64}.{signature}";
+    }
+
+    private long ToUnixTimeSeconds(DateTime dateTime)
+    {
+        return new DateTimeOffset(dateTime).ToUnixTimeSeconds();
+    }
+
+    private string SignWithECDsa(string dataToSign, string privateKey)
+    {
+        using var ecdsa = ECDsa.Create();
+        ecdsa.ImportFromPem(privateKey);
+
+        var bytes = Encoding.UTF8.GetBytes(dataToSign);
+        var signature = ecdsa.SignData(bytes, HashAlgorithmName.SHA256);
+
+        return Base64UrlEncode(signature);
+    }
+
+    private string Base64UrlEncode(byte[] data)
+    {
+        return Convert.ToBase64String(data)
+            .Replace('+', '-')
+            .Replace('/', '_')
+            .TrimEnd('=');
+    }
+}
+
+public class AppleUserData
+{
+    [JsonPropertyName("name")] public AppleNameData? Name { get; set; }
+
+    [JsonPropertyName("email")] public string? Email { get; set; }
+}
+
+public class AppleNameData
+{
+    [JsonPropertyName("firstName")] public string? FirstName { get; set; }
+
+    [JsonPropertyName("lastName")] public string? LastName { get; set; }
+}
+
+public class AppleJwks
+{
+    [JsonPropertyName("keys")] public List<AppleKey> Keys { get; set; } = new List<AppleKey>();
+}
+
+public class AppleKey
+{
+    [JsonPropertyName("kty")] public string? Kty { get; set; }
+
+    [JsonPropertyName("kid")] public string? Kid { get; set; }
+
+    [JsonPropertyName("use")] public string? Use { get; set; }
+
+    [JsonPropertyName("alg")] public string? Alg { get; set; }
+
+    [JsonPropertyName("n")] public string? N { get; set; }
+
+    [JsonPropertyName("e")] public string? E { get; set; }
+
+    public SecurityKey ToSecurityKey()
+    {
+        if (Kty != "RSA" || string.IsNullOrEmpty(N) || string.IsNullOrEmpty(E))
+        {
+            throw new InvalidOperationException("Invalid key data");
+        }
+
+        var parameters = new RSAParameters
+        {
+            Modulus = Base64UrlDecode(N),
+            Exponent = Base64UrlDecode(E)
+        };
+
+        var rsa = RSA.Create();
+        rsa.ImportParameters(parameters);
+
+        return new RsaSecurityKey(rsa);
+    }
+
+    private byte[] Base64UrlDecode(string input)
+    {
+        var output = input
+            .Replace('-', '+')
+            .Replace('_', '/');
+
+        switch (output.Length % 4)
+        {
+            case 0: break;
+            case 2: output += "=="; break;
+            case 3: output += "="; break;
+            default: throw new InvalidOperationException("Invalid base64url string");
+        }
+
+        return Convert.FromBase64String(output);
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/ConnectionController.cs

@@ -0,0 +1,411 @@
+using DysonNetwork.Pass.Features.Account;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using DysonNetwork.Pass.Storage;
+using NodaTime;
+using DysonNetwork.Pass.Data;
+using DysonNetwork.Common.Models;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+[ApiController]
+[Route("/accounts/me/connections")]
+[Authorize]
+public class ConnectionController(
+    PassDatabase db,
+    IEnumerable<OidcService> oidcServices,
+    AccountService accounts,
+    AuthService auth,
+    ICacheService cache
+) : ControllerBase
+{
+    private const string StateCachePrefix = "oidc-state:";
+    private const string ReturnUrlCachePrefix = "oidc-returning:";
+    private static readonly TimeSpan StateExpiration = TimeSpan.FromMinutes(15);
+
+    [HttpGet]
+    public async Task<ActionResult<List<AccountConnection>>> GetConnections()
+    {
+        if (HttpContext.Items["CurrentUser"] is not Models.Account currentUser)
+            return Unauthorized();
+
+        var connections = await db.AccountConnections
+            .Where(c => c.AccountId == currentUser.Id)
+            .Select(c => new
+            {
+                c.Id,
+                c.AccountId,
+                c.Provider,
+                c.ProvidedIdentifier,
+                c.Meta,
+                c.LastUsedAt,
+                c.CreatedAt,
+                c.UpdatedAt,
+            })
+            .ToListAsync();
+        return Ok(connections);
+    }
+
+    [HttpDelete("{id:guid}")]
+    public async Task<ActionResult> RemoveConnection(Guid id)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Models.Account currentUser)
+            return Unauthorized();
+
+        var connection = await db.AccountConnections
+            .Where(c => c.Id == id && c.AccountId == currentUser.Id)
+            .FirstOrDefaultAsync();
+        if (connection == null)
+            return NotFound();
+
+        db.AccountConnections.Remove(connection);
+        await db.SaveChangesAsync();
+
+        return Ok();
+    }
+
+    [HttpPost("/auth/connect/apple/mobile")]
+    public async Task<ActionResult> ConnectAppleMobile([FromBody] AppleMobileConnectRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Models.Account currentUser)
+            return Unauthorized();
+
+        if (GetOidcService("apple") is not AppleOidcService appleService)
+            return StatusCode(503, "Apple OIDC service not available");
+
+        var callbackData = new OidcCallbackData
+        {
+            IdToken = request.IdentityToken,
+            Code = request.AuthorizationCode,
+        };
+
+        OidcUserInfo userInfo;
+        try
+        {
+            userInfo = await appleService.ProcessCallbackAsync(callbackData);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest($"Error processing Apple token: {ex.Message}");
+        }
+
+        var existingConnection = await db.AccountConnections
+            .FirstOrDefaultAsync(c =>
+                c.Provider == "apple" &&
+                c.ProvidedIdentifier == userInfo.UserId);
+
+        if (existingConnection != null)
+        {
+            return BadRequest(
+                $"This Apple account is already linked to {(existingConnection.AccountId == currentUser.Id ? "your account" : "another user")}.");
+        }
+
+        db.AccountConnections.Add(new AccountConnection
+        {
+            AccountId = currentUser.Id,
+            Provider = "apple",
+            ProvidedIdentifier = userInfo.UserId!,
+            AccessToken = userInfo.AccessToken,
+            RefreshToken = userInfo.RefreshToken,
+            LastUsedAt = SystemClock.Instance.GetCurrentInstant(),
+            Meta = userInfo.ToMetadata(),
+        });
+
+        await db.SaveChangesAsync();
+
+        return Ok(new { message = "Successfully connected Apple account." });
+    }
+
+    private OidcService? GetOidcService(string provider)
+    {
+        return oidcServices.FirstOrDefault(s => s.ProviderName.Equals(provider, StringComparison.OrdinalIgnoreCase));
+    }
+
+    public class ConnectProviderRequest
+    {
+        public string Provider { get; set; } = null!;
+        public string? ReturnUrl { get; set; }
+    }
+
+    /// <summary>
+    /// Initiates manual connection to an OAuth provider for the current user
+    /// </summary>
+    [HttpPost("connect")]
+    public async Task<ActionResult<object>> InitiateConnection([FromBody] ConnectProviderRequest request)
+    {
+        if (HttpContext.Items["CurrentUser"] is not Models.Account currentUser)
+            return Unauthorized();
+
+        var oidcService = GetOidcService(request.Provider);
+        if (oidcService == null)
+            return BadRequest($"Provider '{request.Provider}' is not supported");
+
+        var existingConnection = await db.AccountConnections
+            .AnyAsync(c => c.AccountId == currentUser.Id && c.Provider == oidcService.ProviderName);
+
+        if (existingConnection)
+            return BadRequest($"You already have a {request.Provider} connection");
+
+        var state = Guid.NewGuid().ToString("N");
+        var nonce = Guid.NewGuid().ToString("N");
+        var stateValue = $"{currentUser.Id}|{request.Provider}|{nonce}";
+        var finalReturnUrl = !string.IsNullOrEmpty(request.ReturnUrl) ? request.ReturnUrl : "/settings/connections";
+
+        // Store state and return URL in cache
+        await cache.SetAsync($"{StateCachePrefix}{state}", stateValue, StateExpiration);
+        await cache.SetAsync($"{ReturnUrlCachePrefix}{state}", finalReturnUrl, StateExpiration);
+
+        var authUrl = oidcService.GetAuthorizationUrl(state, nonce);
+
+        return Ok(new
+        {
+            authUrl,
+            message = $"Redirect to this URL to connect your {request.Provider} account"
+        });
+    }
+
+    [AllowAnonymous]
+    [Route("/auth/callback/{provider}")]
+    [HttpGet, HttpPost]
+    public async Task<IActionResult> HandleCallback([FromRoute] string provider)
+    {
+        var oidcService = GetOidcService(provider);
+        if (oidcService == null)
+            return BadRequest($"Provider '{provider}' is not supported.");
+
+        var callbackData = await ExtractCallbackData(Request);
+        if (callbackData.State == null)
+            return BadRequest("State parameter is missing.");
+
+        // Get the state from the cache
+        var stateKey = $"{StateCachePrefix}{callbackData.State}";
+        
+        // Try to get the state as OidcState first (new format)
+        var oidcState = await cache.GetAsync<OidcState>(stateKey);
+        
+        // If not found, try to get as string (legacy format)
+        if (oidcState == null)
+        {
+            var stateValue = await cache.GetAsync<string>(stateKey);
+            if (string.IsNullOrEmpty(stateValue) || !OidcState.TryParse(stateValue, out oidcState) || oidcState == null)
+                return BadRequest("Invalid or expired state parameter");
+        }
+        
+        // Remove the state from cache to prevent replay attacks
+        await cache.RemoveAsync(stateKey);
+
+        // Handle the flow based on state type
+        if (oidcState.FlowType == OidcFlowType.Connect && oidcState.AccountId.HasValue)
+        {
+            // Connection flow
+            if (oidcState.DeviceId != null)
+            {
+                callbackData.State = oidcState.DeviceId;
+            }
+            return await HandleManualConnection(provider, oidcService, callbackData, oidcState.AccountId.Value);
+        }
+        else if (oidcState.FlowType == OidcFlowType.Login)
+        {
+            // Login/Registration flow
+            if (!string.IsNullOrEmpty(oidcState.DeviceId))
+            {
+                callbackData.State = oidcState.DeviceId;
+            }
+
+            // Store return URL if provided
+            if (!string.IsNullOrEmpty(oidcState.ReturnUrl) && oidcState.ReturnUrl != "/")
+            {
+                var returnUrlKey = $"{ReturnUrlCachePrefix}{callbackData.State}";
+                await cache.SetAsync(returnUrlKey, oidcState.ReturnUrl, StateExpiration);
+            }
+
+            return await HandleLoginOrRegistration(provider, oidcService, callbackData);
+        }
+
+        return BadRequest("Unsupported flow type");
+    }
+
+    private async Task<IActionResult> HandleManualConnection(
+        string provider,
+        OidcService oidcService,
+        OidcCallbackData callbackData,
+        Guid accountId
+    )
+    {
+        provider = provider.ToLower();
+
+        OidcUserInfo userInfo;
+        try
+        {
+            userInfo = await oidcService.ProcessCallbackAsync(callbackData);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest($"Error processing {provider} authentication: {ex.Message}");
+        }
+
+        if (string.IsNullOrEmpty(userInfo.UserId))
+        {
+            return BadRequest($"{provider} did not return a valid user identifier.");
+        }
+
+        // Extract device ID from the callback state if available
+        var deviceId = !string.IsNullOrEmpty(callbackData.State) ? callbackData.State : string.Empty;
+
+        // Check if this provider account is already connected to any user
+        var existingConnection = await db.AccountConnections
+            .FirstOrDefaultAsync(c =>
+                c.Provider == provider &&
+                c.ProvidedIdentifier == userInfo.UserId);
+
+        // If it's connected to a different user, return error
+        if (existingConnection != null && existingConnection.AccountId != accountId)
+        {
+            return BadRequest($"This {provider} account is already linked to another user.");
+        }
+
+        // Check if the current user already has this provider connected
+        var userHasProvider = await db.AccountConnections
+            .AnyAsync(c =>
+                c.AccountId == accountId &&
+                c.Provider == provider);
+
+        if (userHasProvider)
+        {
+            // Update existing connection with new tokens
+            var connection = await db.AccountConnections
+                .FirstOrDefaultAsync(c =>
+                    c.AccountId == accountId &&
+                    c.Provider == provider);
+
+            if (connection != null)
+            {
+                connection.AccessToken = userInfo.AccessToken;
+                connection.RefreshToken = userInfo.RefreshToken;
+                connection.LastUsedAt = SystemClock.Instance.GetCurrentInstant();
+                connection.Meta = userInfo.ToMetadata();
+            }
+        }
+        else
+        {
+            // Create new connection
+            db.AccountConnections.Add(new AccountConnection
+            {
+                AccountId = accountId,
+                Provider = provider,
+                ProvidedIdentifier = userInfo.UserId!,
+                AccessToken = userInfo.AccessToken,
+                RefreshToken = userInfo.RefreshToken,
+                LastUsedAt = SystemClock.Instance.GetCurrentInstant(),
+                Meta = userInfo.ToMetadata(),
+            });
+        }
+
+        try
+        {
+            await db.SaveChangesAsync();
+        }
+        catch (DbUpdateException)
+        {
+            return StatusCode(500, $"Failed to save {provider} connection. Please try again.");
+        }
+
+        // Clean up and redirect
+        var returnUrlKey = $"{ReturnUrlCachePrefix}{callbackData.State}";
+        var returnUrl = await cache.GetAsync<string>(returnUrlKey);
+        await cache.RemoveAsync(returnUrlKey);
+
+        return Redirect(string.IsNullOrEmpty(returnUrl) ? "/auth/callback" : returnUrl);
+    }
+
+    private async Task<IActionResult> HandleLoginOrRegistration(
+        string provider,
+        OidcService oidcService,
+        OidcCallbackData callbackData
+    )
+    {
+        OidcUserInfo userInfo;
+        try
+        {
+            userInfo = await oidcService.ProcessCallbackAsync(callbackData);
+        }
+        catch (Exception ex)
+        {
+            return BadRequest($"Error processing callback: {ex.Message}");
+        }
+
+        if (string.IsNullOrEmpty(userInfo.Email) || string.IsNullOrEmpty(userInfo.UserId))
+        {
+            return BadRequest($"Email or user ID is missing from {provider}'s response");
+        }
+
+        var connection = await db.AccountConnections
+            .Include(c => c.Account)
+            .FirstOrDefaultAsync(c => c.Provider == provider && c.ProvidedIdentifier == userInfo.UserId);
+
+        var clock = SystemClock.Instance;
+        if (connection != null)
+        {
+            // Login existing user
+            var deviceId = !string.IsNullOrEmpty(callbackData.State) ? 
+                callbackData.State.Split('|').FirstOrDefault() : 
+                string.Empty;
+                
+            var challenge = await oidcService.CreateChallengeForUserAsync(
+                userInfo, 
+                connection.Account, 
+                HttpContext, 
+                deviceId ?? string.Empty);
+            return Redirect($"/auth/callback?challenge={challenge.Id}");
+        }
+
+        // Register new user
+        var account = await accounts.LookupAccount(userInfo.Email) ?? await accounts.CreateAccount(userInfo);
+
+        // Create connection for new or existing user
+        var newConnection = new AccountConnection
+        {
+            Account = account,
+            Provider = provider,
+            ProvidedIdentifier = userInfo.UserId!,
+            AccessToken = userInfo.AccessToken,
+            RefreshToken = userInfo.RefreshToken,
+            LastUsedAt = clock.GetCurrentInstant(),
+            Meta = userInfo.ToMetadata()
+        };
+        db.AccountConnections.Add(newConnection);
+
+        await db.SaveChangesAsync();
+
+        var loginSession = await auth.CreateSessionForOidcAsync(account, clock.GetCurrentInstant());
+        var loginToken = auth.CreateToken(loginSession);
+        return Redirect($"/auth/token?token={loginToken}");
+    }
+
+    private static async Task<OidcCallbackData> ExtractCallbackData(HttpRequest request)
+    {
+        var data = new OidcCallbackData();
+        switch (request.Method)
+        {
+            case "GET":
+                data.Code = Uri.UnescapeDataString(request.Query["code"].FirstOrDefault() ?? "");
+                data.IdToken = Uri.UnescapeDataString(request.Query["id_token"].FirstOrDefault() ?? "");
+                data.State = Uri.UnescapeDataString(request.Query["state"].FirstOrDefault() ?? "");
+                break;
+            case "POST" when request.HasFormContentType:
+            {
+                var form = await request.ReadFormAsync();
+                data.Code = Uri.UnescapeDataString(form["code"].FirstOrDefault() ?? "");
+                data.IdToken = Uri.UnescapeDataString(form["id_token"].FirstOrDefault() ?? ""); 
+                data.State = Uri.UnescapeDataString(form["state"].FirstOrDefault() ?? "");
+                if (form.ContainsKey("user"))
+                    data.RawData = Uri.UnescapeDataString(form["user"].FirstOrDefault() ?? "");
+
+                break;
+            }
+        }
+
+        return data;
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/DiscordOidcService.cs

@@ -0,0 +1,115 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+using DysonNetwork.Pass.Storage;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+public class DiscordOidcService(
+    IConfiguration configuration,
+    IHttpClientFactory httpClientFactory,
+    PassDatabase db,
+    AuthService auth,
+    ICacheService cache
+)
+    : OidcService(configuration, httpClientFactory, db, auth, cache)
+{
+    public override string ProviderName => "Discord";
+    protected override string DiscoveryEndpoint => ""; // Discord doesn't have a standard OIDC discovery endpoint
+    protected override string ConfigSectionName => "Discord";
+
+    public override string GetAuthorizationUrl(string state, string nonce)
+    {
+        var config = GetProviderConfig();
+        var queryParams = new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "redirect_uri", config.RedirectUri },
+            { "response_type", "code" },
+            { "scope", "identify email" },
+            { "state", state },
+        };
+
+        var queryString = string.Join("&", queryParams.Select(p => $"{p.Key}={Uri.EscapeDataString(p.Value)}"));
+        return $"https://discord.com/oauth2/authorize?{queryString}";
+    }
+    
+    protected override Task<OidcDiscoveryDocument?> GetDiscoveryDocumentAsync()
+    {
+        return Task.FromResult(new OidcDiscoveryDocument
+        {
+            AuthorizationEndpoint = "https://discord.com/oauth2/authorize",
+            TokenEndpoint = "https://discord.com/oauth2/token",
+            UserinfoEndpoint = "https://discord.com/users/@me",
+            JwksUri = null
+        })!;
+    }
+    
+    public override async Task<OidcUserInfo> ProcessCallbackAsync(OidcCallbackData callbackData)
+    {
+        var tokenResponse = await ExchangeCodeForTokensAsync(callbackData.Code);
+        if (tokenResponse?.AccessToken == null)
+        {
+            throw new InvalidOperationException("Failed to obtain access token from Discord");
+        }
+
+        var userInfo = await GetUserInfoAsync(tokenResponse.AccessToken);
+
+        userInfo.AccessToken = tokenResponse.AccessToken;
+        userInfo.RefreshToken = tokenResponse.RefreshToken;
+
+        return userInfo;
+    }
+
+    protected override async Task<OidcTokenResponse?> ExchangeCodeForTokensAsync(string code,
+        string? codeVerifier = null)
+    {
+        var config = GetProviderConfig();
+        var client = HttpClientFactory.CreateClient();
+
+        var content = new FormUrlEncodedContent(new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "client_secret", config.ClientSecret },
+            { "grant_type", "authorization_code" },
+            { "code", code },
+            { "redirect_uri", config.RedirectUri },
+        });
+
+        var response = await client.PostAsync("https://discord.com/oauth2/token", content);
+        response.EnsureSuccessStatusCode();
+
+        return await response.Content.ReadFromJsonAsync<OidcTokenResponse>();
+    }
+
+    private async Task<OidcUserInfo> GetUserInfoAsync(string accessToken)
+    {
+        var client = HttpClientFactory.CreateClient();
+        var request = new HttpRequestMessage(HttpMethod.Get, "https://discord.com/users/@me");
+        request.Headers.Add("Authorization", $"Bearer {accessToken}");
+
+        var response = await client.SendAsync(request);
+        response.EnsureSuccessStatusCode();
+
+        var json = await response.Content.ReadAsStringAsync();
+        var discordUser = JsonDocument.Parse(json).RootElement;
+
+        var userId = discordUser.GetProperty("id").GetString() ?? "";
+        var avatar = discordUser.TryGetProperty("avatar", out var avatarElement) ? avatarElement.GetString() : null;
+
+        return new OidcUserInfo
+        {
+            UserId = userId,
+            Email = (discordUser.TryGetProperty("email", out var emailElement) ? emailElement.GetString() : null) ?? "",
+            EmailVerified = discordUser.TryGetProperty("verified", out var verifiedElement) &&
+                            verifiedElement.GetBoolean(),
+            DisplayName = (discordUser.TryGetProperty("global_name", out var globalNameElement)
+                ? globalNameElement.GetString()
+                : null) ?? "",
+            PreferredUsername = discordUser.GetProperty("username").GetString() ?? "",
+            ProfilePictureUrl = !string.IsNullOrEmpty(avatar)
+                ? $"https://cdn.discordapp.com/avatars/{userId}/{avatar}.png"
+                : "",
+            Provider = ProviderName
+        };
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/GitHubOidcService.cs

@@ -0,0 +1,127 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+using DysonNetwork.Pass.Storage;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+public class GitHubOidcService(
+    IConfiguration configuration,
+    IHttpClientFactory httpClientFactory,
+    PassDatabase db,
+    AuthService auth,
+    ICacheService cache
+)
+    : OidcService(configuration, httpClientFactory, db, auth, cache)
+{
+    public override string ProviderName => "GitHub";
+    protected override string DiscoveryEndpoint => ""; // GitHub doesn't have a standard OIDC discovery endpoint
+    protected override string ConfigSectionName => "GitHub";
+
+    public override string GetAuthorizationUrl(string state, string nonce)
+    {
+        var config = GetProviderConfig();
+        var queryParams = new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "redirect_uri", config.RedirectUri },
+            { "scope", "user:email" },
+            { "state", state },
+        };
+
+        var queryString = string.Join("&", queryParams.Select(p => $"{p.Key}={Uri.EscapeDataString(p.Value)}"));
+        return $"https://github.com/login/oauth/authorize?{queryString}";
+    }
+
+    public override async Task<OidcUserInfo> ProcessCallbackAsync(OidcCallbackData callbackData)
+    {
+        var tokenResponse = await ExchangeCodeForTokensAsync(callbackData.Code);
+        if (tokenResponse?.AccessToken == null)
+        {
+            throw new InvalidOperationException("Failed to obtain access token from GitHub");
+        }
+
+        var userInfo = await GetUserInfoAsync(tokenResponse.AccessToken);
+
+        userInfo.AccessToken = tokenResponse.AccessToken;
+        userInfo.RefreshToken = tokenResponse.RefreshToken;
+
+        return userInfo;
+    }
+
+    protected override async Task<OidcTokenResponse?> ExchangeCodeForTokensAsync(string code,
+        string? codeVerifier = null)
+    {
+        var config = GetProviderConfig();
+        var client = HttpClientFactory.CreateClient();
+
+        var tokenRequest = new HttpRequestMessage(HttpMethod.Post, "https://github.com/login/oauth/access_token")
+        {
+            Content = new FormUrlEncodedContent(new Dictionary<string, string>
+            {
+                { "client_id", config.ClientId },
+                { "client_secret", config.ClientSecret },
+                { "code", code },
+                { "redirect_uri", config.RedirectUri },
+            })
+        };
+        tokenRequest.Headers.Add("Accept", "application/json");
+
+        var response = await client.SendAsync(tokenRequest);
+        response.EnsureSuccessStatusCode();
+
+        return await response.Content.ReadFromJsonAsync<OidcTokenResponse>();
+    }
+
+    private async Task<OidcUserInfo> GetUserInfoAsync(string accessToken)
+    {
+        var client = HttpClientFactory.CreateClient();
+        var request = new HttpRequestMessage(HttpMethod.Get, "https://api.github.com/user");
+        request.Headers.Add("Authorization", $"Bearer {accessToken}");
+        request.Headers.Add("User-Agent", "DysonNetwork.Sphere");
+
+        var response = await client.SendAsync(request);
+        response.EnsureSuccessStatusCode();
+
+        var json = await response.Content.ReadAsStringAsync();
+        var githubUser = JsonDocument.Parse(json).RootElement;
+
+        var email = githubUser.TryGetProperty("email", out var emailElement) ? emailElement.GetString() : null;
+        if (string.IsNullOrEmpty(email))
+        {
+            email = await GetPrimaryEmailAsync(accessToken);
+        }
+
+        return new OidcUserInfo
+        {
+            UserId = githubUser.GetProperty("id").GetInt64().ToString(),
+            Email = email,
+            DisplayName = githubUser.TryGetProperty("name", out var nameElement) ? nameElement.GetString() ?? "" : "",
+            PreferredUsername = githubUser.GetProperty("login").GetString() ?? "",
+            ProfilePictureUrl = githubUser.TryGetProperty("avatar_url", out var avatarElement)
+                ? avatarElement.GetString() ?? ""
+                : "",
+            Provider = ProviderName
+        };
+    }
+
+    private async Task<string?> GetPrimaryEmailAsync(string accessToken)
+    {
+        var client = HttpClientFactory.CreateClient();
+        var request = new HttpRequestMessage(HttpMethod.Get, "https://api.github.com/user/emails");
+        request.Headers.Add("Authorization", $"Bearer {accessToken}");
+        request.Headers.Add("User-Agent", "DysonNetwork.Sphere");
+
+        var response = await client.SendAsync(request);
+        if (!response.IsSuccessStatusCode) return null;
+
+        var emails = await response.Content.ReadFromJsonAsync<List<GitHubEmail>>();
+        return emails?.FirstOrDefault(e => e.Primary)?.Email;
+    }
+
+    private class GitHubEmail
+    {
+        public string Email { get; set; } = "";
+        public bool Primary { get; set; }
+        public bool Verified { get; set; }
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/GoogleOidcService.cs

@@ -0,0 +1,136 @@
+using System.IdentityModel.Tokens.Jwt;
+using System.Net.Http.Json;
+using System.Security.Cryptography;
+using System.Text;
+using DysonNetwork.Common.Services;
+using Microsoft.IdentityModel.Tokens;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+public class GoogleOidcService(
+    IConfiguration configuration,
+    IHttpClientFactory httpClientFactory,
+    PassDatabase db,
+    AuthService auth,
+    ICacheService cache
+)
+    : OidcService(configuration, httpClientFactory, db, auth, cache)
+{
+    private readonly IHttpClientFactory _httpClientFactory = httpClientFactory;
+
+    public override string ProviderName => "google";
+    protected override string DiscoveryEndpoint => "https://accounts.google.com/.well-known/openid-configuration";
+    protected override string ConfigSectionName => "Google";
+
+    public override string GetAuthorizationUrl(string state, string nonce)
+    {
+        var config = GetProviderConfig();
+        var discoveryDocument = GetDiscoveryDocumentAsync().GetAwaiter().GetResult();
+
+        if (discoveryDocument?.AuthorizationEndpoint == null)
+        {
+            throw new InvalidOperationException("Authorization endpoint not found in discovery document");
+        }
+
+        var queryParams = new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "redirect_uri", config.RedirectUri },
+            { "response_type", "code" },
+            { "scope", "openid email profile" },
+            { "state", state }, // No '|codeVerifier' appended anymore
+            { "nonce", nonce }
+        };
+
+        var queryString = string.Join("&", queryParams.Select(p => $"{p.Key}={Uri.EscapeDataString(p.Value)}"));
+        return $"{discoveryDocument.AuthorizationEndpoint}?{queryString}";
+    }
+
+    public override async Task<OidcUserInfo> ProcessCallbackAsync(OidcCallbackData callbackData)
+    {
+        // No need to split or parse code verifier from state
+        var state = callbackData.State ?? "";
+        callbackData.State = state; // Keep the original state if needed
+
+        // Exchange the code for tokens
+        // Pass null or omit the parameter for codeVerifier as PKCE is removed
+        var tokenResponse = await ExchangeCodeForTokensAsync(callbackData.Code, null);
+        if (tokenResponse?.IdToken == null)
+        {
+            throw new InvalidOperationException("Failed to obtain ID token from Google");
+        }
+
+        // Validate the ID token
+        var userInfo = await ValidateTokenAsync(tokenResponse.IdToken);
+
+        // Set tokens on the user info
+        userInfo.AccessToken = tokenResponse.AccessToken;
+        userInfo.RefreshToken = tokenResponse.RefreshToken;
+
+        // Try to fetch additional profile data if userinfo endpoint is available
+        try
+        {
+            var discoveryDocument = await GetDiscoveryDocumentAsync();
+            if (discoveryDocument?.UserinfoEndpoint != null && !string.IsNullOrEmpty(tokenResponse.AccessToken))
+            {
+                var client = _httpClientFactory.CreateClient();
+                client.DefaultRequestHeaders.Authorization =
+                    new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", tokenResponse.AccessToken);
+
+                var userInfoResponse =
+                    await client.GetFromJsonAsync<Dictionary<string, object>>(discoveryDocument.UserinfoEndpoint);
+
+                if (userInfoResponse != null)
+                {
+                    if (userInfoResponse.TryGetValue("picture", out var picture) && picture != null)
+                    {
+                        userInfo.ProfilePictureUrl = picture.ToString();
+                    }
+                }
+            }
+        }
+        catch
+        {
+            // Ignore errors when fetching additional profile data
+        }
+
+        return userInfo;
+    }
+
+    private async Task<OidcUserInfo> ValidateTokenAsync(string idToken)
+    {
+        var discoveryDocument = await GetDiscoveryDocumentAsync();
+        if (discoveryDocument?.JwksUri == null)
+        {
+            throw new InvalidOperationException("JWKS URI not found in discovery document");
+        }
+
+        var client = _httpClientFactory.CreateClient();
+        var jwksResponse = await client.GetFromJsonAsync<JsonWebKeySet>(discoveryDocument.JwksUri);
+        if (jwksResponse == null)
+        {
+            throw new InvalidOperationException("Failed to retrieve JWKS from Google");
+        }
+
+        var handler = new JwtSecurityTokenHandler();
+        var jwtToken = handler.ReadJwtToken(idToken);
+        var kid = jwtToken.Header.Kid;
+        var signingKey = jwksResponse.Keys.FirstOrDefault(k => k.Kid == kid);
+        if (signingKey == null)
+        {
+            throw new SecurityTokenValidationException("Unable to find matching key in Google's JWKS");
+        }
+
+        var validationParameters = new TokenValidationParameters
+        {
+            ValidateIssuer = true,
+            ValidIssuer = "https://accounts.google.com",
+            ValidateAudience = true,
+            ValidAudience = GetProviderConfig().ClientId,
+            ValidateLifetime = true,
+            IssuerSigningKey = signingKey
+        };
+
+        return ValidateAndExtractIdToken(idToken, validationParameters);
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/MicrosoftOidcService.cs

@@ -0,0 +1,124 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+using DysonNetwork.Pass.Storage;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+public class MicrosoftOidcService(
+    IConfiguration configuration,
+    IHttpClientFactory httpClientFactory,
+    PassDatabase db,
+    AuthService auth,
+    ICacheService cache
+)
+    : OidcService(configuration, httpClientFactory, db, auth, cache)
+{
+    public override string ProviderName => "Microsoft";
+
+    protected override string DiscoveryEndpoint => Configuration[$"Oidc:{ConfigSectionName}:DiscoveryEndpoint"] ??
+                                                   throw new InvalidOperationException(
+                                                       "Microsoft OIDC discovery endpoint is not configured.");
+
+    protected override string ConfigSectionName => "Microsoft";
+
+    public override string GetAuthorizationUrl(string state, string nonce)
+    {
+        var config = GetProviderConfig();
+        var discoveryDocument = GetDiscoveryDocumentAsync().GetAwaiter().GetResult();
+        if (discoveryDocument?.AuthorizationEndpoint == null)
+            throw new InvalidOperationException("Authorization endpoint not found in discovery document.");
+
+        var queryParams = new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "response_type", "code" },
+            { "redirect_uri", config.RedirectUri },
+            { "response_mode", "query" },
+            { "scope", "openid profile email" },
+            { "state", state },
+            { "nonce", nonce },
+        };
+
+        var queryString = string.Join("&", queryParams.Select(p => $"{p.Key}={Uri.EscapeDataString(p.Value)}"));
+        return $"{discoveryDocument.AuthorizationEndpoint}?{queryString}";
+    }
+
+    public override async Task<OidcUserInfo> ProcessCallbackAsync(OidcCallbackData callbackData)
+    {
+        var tokenResponse = await ExchangeCodeForTokensAsync(callbackData.Code);
+        if (tokenResponse?.AccessToken == null)
+        {
+            throw new InvalidOperationException("Failed to obtain access token from Microsoft");
+        }
+
+        var userInfo = await GetUserInfoAsync(tokenResponse.AccessToken);
+
+        userInfo.AccessToken = tokenResponse.AccessToken;
+        userInfo.RefreshToken = tokenResponse.RefreshToken;
+
+        return userInfo;
+    }
+
+    protected override async Task<OidcTokenResponse?> ExchangeCodeForTokensAsync(string code,
+        string? codeVerifier = null)
+    {
+        var config = GetProviderConfig();
+        var discoveryDocument = await GetDiscoveryDocumentAsync();
+        if (discoveryDocument?.TokenEndpoint == null)
+        {
+            throw new InvalidOperationException("Token endpoint not found in discovery document.");
+        }
+
+        var client = HttpClientFactory.CreateClient();
+
+        var tokenRequest = new HttpRequestMessage(HttpMethod.Post, discoveryDocument.TokenEndpoint)
+        {
+            Content = new FormUrlEncodedContent(new Dictionary<string, string>
+            {
+                { "client_id", config.ClientId },
+                { "scope", "openid profile email" },
+                { "code", code },
+                { "redirect_uri", config.RedirectUri },
+                { "grant_type", "authorization_code" },
+                { "client_secret", config.ClientSecret },
+            })
+        };
+
+        var response = await client.SendAsync(tokenRequest);
+        response.EnsureSuccessStatusCode();
+
+        return await response.Content.ReadFromJsonAsync<OidcTokenResponse>();
+    }
+
+    private async Task<OidcUserInfo> GetUserInfoAsync(string accessToken)
+    {
+        var discoveryDocument = await GetDiscoveryDocumentAsync();
+        if (discoveryDocument?.UserinfoEndpoint == null)
+            throw new InvalidOperationException("Userinfo endpoint not found in discovery document.");
+
+        var client = HttpClientFactory.CreateClient();
+        var request = new HttpRequestMessage(HttpMethod.Get, discoveryDocument.UserinfoEndpoint);
+        request.Headers.Add("Authorization", $"Bearer {accessToken}");
+
+        var response = await client.SendAsync(request);
+        response.EnsureSuccessStatusCode();
+
+        var json = await response.Content.ReadAsStringAsync();
+        var microsoftUser = JsonDocument.Parse(json).RootElement;
+
+        return new OidcUserInfo
+        {
+            UserId = microsoftUser.GetProperty("sub").GetString() ?? "",
+            Email = microsoftUser.TryGetProperty("email", out var emailElement) ? emailElement.GetString() : null,
+            DisplayName =
+                microsoftUser.TryGetProperty("name", out var nameElement) ? nameElement.GetString() ?? "" : "",
+            PreferredUsername = microsoftUser.TryGetProperty("preferred_username", out var preferredUsernameElement)
+                ? preferredUsernameElement.GetString() ?? ""
+                : "",
+            ProfilePictureUrl = microsoftUser.TryGetProperty("picture", out var pictureElement)
+                ? pictureElement.GetString() ?? ""
+                : "",
+            Provider = ProviderName
+        };
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/OidcController.cs

@@ -0,0 +1,193 @@
+using DysonNetwork.Common.Services;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.IdentityModel.Tokens;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+[ApiController]
+[Route("/auth/login")]
+public class OidcController(
+    IServiceProvider serviceProvider,
+    PassDatabase db,
+    AccountService accounts,
+    ICacheService cache
+)
+    : ControllerBase
+{
+    private const string StateCachePrefix = "oidc-state:";
+    private static readonly TimeSpan StateExpiration = TimeSpan.FromMinutes(15);
+
+    [HttpGet("{provider}")]
+    public async Task<ActionResult> OidcLogin(
+        [FromRoute] string provider,
+        [FromQuery] string? returnUrl = "/",
+        [FromHeader(Name = "X-Device-Id")] string? deviceId = null
+    )
+    {
+        try
+        {
+            var oidcService = GetOidcService(provider);
+
+            // If the user is already authenticated, treat as an account connection request
+            if (HttpContext.Items["CurrentUser"] is Models.Account currentUser)
+            {
+                var state = Guid.NewGuid().ToString();
+                var nonce = Guid.NewGuid().ToString();
+
+                // Create and store connection state
+                var oidcState = OidcState.ForConnection(currentUser.Id, provider, nonce, deviceId);
+                await cache.SetAsync($"{StateCachePrefix}{state}", oidcState, StateExpiration);
+
+                // The state parameter sent to the provider is the GUID key for the cache.
+                var authUrl = oidcService.GetAuthorizationUrl(state, nonce);
+                return Redirect(authUrl);
+            }
+            else // Otherwise, proceed with the login / registration flow
+            {
+                var nonce = Guid.NewGuid().ToString();
+                var state = Guid.NewGuid().ToString();
+
+                // Create login state with return URL and device ID
+                var oidcState = OidcState.ForLogin(returnUrl ?? "/", deviceId);
+                await cache.SetAsync($"{StateCachePrefix}{state}", oidcState, StateExpiration);
+                var authUrl = oidcService.GetAuthorizationUrl(state, nonce);
+                return Redirect(authUrl);
+            }
+        }
+        catch (Exception ex)
+        {
+            return BadRequest($"Error initiating OpenID Connect flow: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    /// Mobile Apple Sign In endpoint
+    /// Handles Apple authentication directly from mobile apps
+    /// </summary>
+    [HttpPost("apple/mobile")]
+    public async Task<ActionResult<Challenge>> AppleMobileLogin(
+        [FromBody] AppleMobileSignInRequest request)
+    {
+        try
+        {
+            // Get Apple OIDC service
+            if (GetOidcService("apple") is not AppleOidcService appleService)
+                return StatusCode(503, "Apple OIDC service not available");
+
+            // Prepare callback data for processing
+            var callbackData = new OidcCallbackData
+            {
+                IdToken = request.IdentityToken,
+                Code = request.AuthorizationCode,
+            };
+
+            // Process the authentication
+            var userInfo = await appleService.ProcessCallbackAsync(callbackData);
+
+            // Find or create user account using existing logic
+            var account = await FindOrCreateAccount(userInfo, "apple");
+
+            // Create session using the OIDC service
+            var challenge = await appleService.CreateChallengeForUserAsync(
+                userInfo,
+                account,
+                HttpContext,
+                request.DeviceId
+            );
+
+            return Ok(challenge);
+        }
+        catch (SecurityTokenValidationException ex)
+        {
+            return Unauthorized($"Invalid identity token: {ex.Message}");
+        }
+        catch (Exception ex)
+        {
+            // Log the error
+            return StatusCode(500, $"Authentication failed: {ex.Message}");
+        }
+    }
+
+    private OidcService GetOidcService(string provider)
+    {
+        return provider.ToLower() switch
+        {
+            "apple" => serviceProvider.GetRequiredService<AppleOidcService>(),
+            "google" => serviceProvider.GetRequiredService<GoogleOidcService>(),
+            "microsoft" => serviceProvider.GetRequiredService<MicrosoftOidcService>(),
+            "discord" => serviceProvider.GetRequiredService<DiscordOidcService>(),
+            "github" => serviceProvider.GetRequiredService<GitHubOidcService>(),
+            "afdian" => serviceProvider.GetRequiredService<AfdianOidcService>(),
+            _ => throw new ArgumentException($"Unsupported provider: {provider}")
+        };
+    }
+
+    private async Task<Models.Account> FindOrCreateAccount(OidcUserInfo userInfo, string provider)
+    {
+        if (string.IsNullOrEmpty(userInfo.Email))
+            throw new ArgumentException("Email is required for account creation");
+
+        // Check if an account exists by email
+        var existingAccount = await accounts.LookupAccount(userInfo.Email);
+        if (existingAccount != null)
+        {
+            // Check if this provider connection already exists
+            var existingConnection = await db.AccountConnections
+                .FirstOrDefaultAsync(c => c.AccountId == existingAccount.Id &&
+                                          c.Provider == provider &&
+                                          c.ProvidedIdentifier == userInfo.UserId);
+
+            // If no connection exists, create one
+            if (existingConnection != null)
+            {
+                await db.AccountConnections
+                    .Where(c => c.AccountId == existingAccount.Id &&
+                                c.Provider == provider &&
+                                c.ProvidedIdentifier == userInfo.UserId)
+                    .ExecuteUpdateAsync(s => s
+                        .SetProperty(c => c.LastUsedAt, SystemClock.Instance.GetCurrentInstant())
+                        .SetProperty(c => c.Meta, userInfo.ToMetadata()));
+
+                return existingAccount;
+            }
+
+            var connection = new AccountConnection
+            {
+                AccountId = existingAccount.Id,
+                Provider = provider,
+                ProvidedIdentifier = userInfo.UserId!,
+                AccessToken = userInfo.AccessToken,
+                RefreshToken = userInfo.RefreshToken,
+                LastUsedAt = SystemClock.Instance.GetCurrentInstant(),
+                Meta = userInfo.ToMetadata()
+            };
+
+            await db.AccountConnections.AddAsync(connection);
+            await db.SaveChangesAsync();
+
+            return existingAccount;
+        }
+
+        // Create new account using the AccountService
+        var newAccount = await accounts.CreateAccount(userInfo);
+
+        // Create the provider connection
+        var newConnection = new AccountConnection
+        {
+            AccountId = newAccount.Id,
+            Provider = provider,
+            ProvidedIdentifier = userInfo.UserId!,
+            AccessToken = userInfo.AccessToken,
+            RefreshToken = userInfo.RefreshToken,
+            LastUsedAt = SystemClock.Instance.GetCurrentInstant(),
+            Meta = userInfo.ToMetadata()
+        };
+
+        db.AccountConnections.Add(newConnection);
+        await db.SaveChangesAsync();
+
+        return newAccount;
+    }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/OidcService.cs

@@ -0,0 +1,294 @@
+using System.IdentityModel.Tokens.Jwt;
+using System.Net.Http.Json;
+using System.Text.Json.Serialization;
+using DysonNetwork.Common.Services;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.IdentityModel.Tokens;
+using NodaTime;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+/// <summary>
+/// Base service for OpenID Connect authentication providers
+/// </summary>
+public abstract class OidcService(
+    IConfiguration configuration,
+    IHttpClientFactory httpClientFactory,
+    PassDatabase db,
+    AuthService auth,
+    ICacheService cache
+)
+{
+    protected readonly IConfiguration Configuration = configuration;
+    protected readonly IHttpClientFactory HttpClientFactory = httpClientFactory;
+    protected readonly AppDatabase Db = db;
+
+    /// <summary>
+    /// Gets the unique identifier for this provider
+    /// </summary>
+    public abstract string ProviderName { get; }
+
+    /// <summary>
+    /// Gets the OIDC discovery document endpoint
+    /// </summary>
+    protected abstract string DiscoveryEndpoint { get; }
+
+    /// <summary>
+    /// Gets configuration section name for this provider
+    /// </summary>
+    protected abstract string ConfigSectionName { get; }
+
+    /// <summary>
+    /// Gets the authorization URL for initiating the authentication flow
+    /// </summary>
+    public abstract string GetAuthorizationUrl(string state, string nonce);
+
+    /// <summary>
+    /// Process the callback from the OIDC provider
+    /// </summary>
+    public abstract Task<OidcUserInfo> ProcessCallbackAsync(OidcCallbackData callbackData);
+
+    /// <summary>
+    /// Gets the provider configuration
+    /// </summary>
+    protected ProviderConfiguration GetProviderConfig()
+    {
+        return new ProviderConfiguration
+        {
+            ClientId = Configuration[$"Oidc:{ConfigSectionName}:ClientId"] ?? "",
+            ClientSecret = Configuration[$"Oidc:{ConfigSectionName}:ClientSecret"] ?? "",
+            RedirectUri = Configuration["BaseUrl"] + "/auth/callback/" + ProviderName.ToLower()
+        };
+    }
+
+    /// <summary>
+    /// Retrieves the OpenID Connect discovery document
+    /// </summary>
+    protected virtual async Task<OidcDiscoveryDocument?> GetDiscoveryDocumentAsync()
+    {
+        // Construct a cache key unique to the current provider:
+        var cacheKey = $"oidc-discovery:{ProviderName}";
+
+        // Try getting the discovery document from cache first:
+        var (found, cachedDoc) = await cache.GetAsyncWithStatus<OidcDiscoveryDocument>(cacheKey);
+        if (found && cachedDoc != null)
+        {
+            return cachedDoc;
+        }
+
+        // If it's not cached, fetch from the actual discovery endpoint:
+        var client = HttpClientFactory.CreateClient();
+        var response = await client.GetAsync(DiscoveryEndpoint);
+        response.EnsureSuccessStatusCode();
+        var doc = await response.Content.ReadFromJsonAsync<OidcDiscoveryDocument>();
+
+        // Store the discovery document in the cache for a while (e.g., 15 minutes):
+        if (doc is not null)
+            await cache.SetAsync(cacheKey, doc, TimeSpan.FromMinutes(15));
+
+        return doc;
+
+    }
+
+    /// <summary>
+    /// Exchange the authorization code for tokens
+    /// </summary>
+    protected virtual async Task<OidcTokenResponse?> ExchangeCodeForTokensAsync(string code,
+        string? codeVerifier = null)
+    {
+        var config = GetProviderConfig();
+        var discoveryDocument = await GetDiscoveryDocumentAsync();
+
+        if (discoveryDocument?.TokenEndpoint == null)
+        {
+            throw new InvalidOperationException("Token endpoint not found in discovery document");
+        }
+
+        var client = HttpClientFactory.CreateClient();
+        var content = new FormUrlEncodedContent(BuildTokenRequestParameters(code, config, codeVerifier));
+
+        var response = await client.PostAsync(discoveryDocument.TokenEndpoint, content);
+        response.EnsureSuccessStatusCode();
+
+        return await response.Content.ReadFromJsonAsync<OidcTokenResponse>();
+    }
+
+    /// <summary>
+    /// Build the token request parameters
+    /// </summary>
+    protected virtual Dictionary<string, string> BuildTokenRequestParameters(string code, ProviderConfiguration config,
+        string? codeVerifier)
+    {
+        var parameters = new Dictionary<string, string>
+        {
+            { "client_id", config.ClientId },
+            { "code", code },
+            { "grant_type", "authorization_code" },
+            { "redirect_uri", config.RedirectUri }
+        };
+
+        if (!string.IsNullOrEmpty(config.ClientSecret))
+        {
+            parameters.Add("client_secret", config.ClientSecret);
+        }
+
+        if (!string.IsNullOrEmpty(codeVerifier))
+        {
+            parameters.Add("code_verifier", codeVerifier);
+        }
+
+        return parameters;
+    }
+
+    /// <summary>
+    /// Validates and extracts information from an ID token
+    /// </summary>
+    protected virtual OidcUserInfo ValidateAndExtractIdToken(string idToken,
+        TokenValidationParameters validationParameters)
+    {
+        var handler = new JwtSecurityTokenHandler();
+        handler.ValidateToken(idToken, validationParameters, out _);
+
+        var jwtToken = handler.ReadJwtToken(idToken);
+
+        // Extract standard claims
+        var userId = jwtToken.Claims.FirstOrDefault(c => c.Type == "sub")?.Value;
+        var email = jwtToken.Claims.FirstOrDefault(c => c.Type == "email")?.Value;
+        var emailVerified = jwtToken.Claims.FirstOrDefault(c => c.Type == "email_verified")?.Value == "true";
+        var name = jwtToken.Claims.FirstOrDefault(c => c.Type == "name")?.Value;
+        var givenName = jwtToken.Claims.FirstOrDefault(c => c.Type == "given_name")?.Value;
+        var familyName = jwtToken.Claims.FirstOrDefault(c => c.Type == "family_name")?.Value;
+        var preferredUsername = jwtToken.Claims.FirstOrDefault(c => c.Type == "preferred_username")?.Value;
+        var picture = jwtToken.Claims.FirstOrDefault(c => c.Type == "picture")?.Value;
+
+        // Determine preferred username - try different options
+        var username = preferredUsername;
+        if (string.IsNullOrEmpty(username))
+        {
+            // Fall back to email local part if no preferred username
+            username = !string.IsNullOrEmpty(email) ? email.Split('@')[0] : null;
+        }
+
+        return new OidcUserInfo
+        {
+            UserId = userId,
+            Email = email,
+            EmailVerified = emailVerified,
+            FirstName = givenName ?? "",
+            LastName = familyName ?? "",
+            DisplayName = name ?? $"{givenName} {familyName}".Trim(),
+            PreferredUsername = username ?? "",
+            ProfilePictureUrl = picture,
+            Provider = ProviderName
+        };
+    }
+
+    /// <summary>
+    /// Creates a challenge and session for an authenticated user
+    /// Also creates or updates the account connection
+    /// </summary>
+    public async Task<Challenge> CreateChallengeForUserAsync(
+        OidcUserInfo userInfo,
+        Models.Account account,
+        HttpContext request,
+        string deviceId
+    )
+    {
+        // Create or update the account connection
+        var connection = await Db.AccountConnections
+            .FirstOrDefaultAsync(c => c.Provider == ProviderName &&
+                                      c.ProvidedIdentifier == userInfo.UserId &&
+                                      c.AccountId == account.Id
+            );
+
+        if (connection is null)
+        {
+            connection = new AccountConnection
+            {
+                Provider = ProviderName,
+                ProvidedIdentifier = userInfo.UserId ?? "",
+                AccessToken = userInfo.AccessToken,
+                RefreshToken = userInfo.RefreshToken,
+                LastUsedAt = SystemClock.Instance.GetCurrentInstant(),
+                AccountId = account.Id
+            };
+            await Db.AccountConnections.AddAsync(connection);
+        }
+
+        // Create a challenge that's already completed
+        var now = SystemClock.Instance.GetCurrentInstant();
+        var challenge = new Challenge
+        {
+            ExpiredAt = now.Plus(Duration.FromHours(1)),
+            StepTotal = await auth.DetectChallengeRisk(request.Request, account),
+            Type = ChallengeType.Oidc,
+            Platform = ChallengePlatform.Unidentified,
+            Audiences = [ProviderName],
+            Scopes = ["*"],
+            AccountId = account.Id,
+            DeviceId = deviceId,
+            IpAddress = request.Connection.RemoteIpAddress?.ToString() ?? null,
+            UserAgent = request.Request.Headers.UserAgent,
+        };
+        challenge.StepRemain--;
+        if (challenge.StepRemain < 0) challenge.StepRemain = 0;
+
+        await Db.AuthChallenges.AddAsync(challenge);
+        await Db.SaveChangesAsync();
+
+        return challenge;
+    }
+}
+
+/// <summary>
+/// Provider configuration from app settings
+/// </summary>
+public class ProviderConfiguration
+{
+    public string ClientId { get; set; } = "";
+    public string ClientSecret { get; set; } = "";
+    public string RedirectUri { get; set; } = "";
+}
+
+/// <summary>
+/// OIDC Discovery Document
+/// </summary>
+public class OidcDiscoveryDocument
+{
+    [JsonPropertyName("authorization_endpoint")]
+    public string? AuthorizationEndpoint { get; set; }
+
+    [JsonPropertyName("token_endpoint")] public string? TokenEndpoint { get; set; }
+
+    [JsonPropertyName("userinfo_endpoint")]
+    public string? UserinfoEndpoint { get; set; }
+
+    [JsonPropertyName("jwks_uri")] public string? JwksUri { get; set; }
+}
+
+/// <summary>
+/// Response from the token endpoint
+/// </summary>
+public class OidcTokenResponse
+{
+    [JsonPropertyName("access_token")] public string? AccessToken { get; set; }
+
+    [JsonPropertyName("token_type")] public string? TokenType { get; set; }
+
+    [JsonPropertyName("expires_in")] public int ExpiresIn { get; set; }
+
+    [JsonPropertyName("refresh_token")] public string? RefreshToken { get; set; }
+
+    [JsonPropertyName("id_token")] public string? IdToken { get; set; }
+}
+
+/// <summary>
+/// Data received in the callback from an OIDC provider
+/// </summary>
+public class OidcCallbackData
+{
+    public string Code { get; set; } = "";
+    public string IdToken { get; set; } = "";
+    public string? State { get; set; }
+    public string? RawData { get; set; }
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/OidcState.cs

@@ -0,0 +1,189 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+/// <summary>
+/// Represents the state parameter used in OpenID Connect flows.
+/// Handles serialization and deserialization of the state parameter.
+/// </summary>
+public class OidcState
+{
+    /// <summary>
+    /// The type of OIDC flow (login or connect).
+    /// </summary>
+    public OidcFlowType FlowType { get; set; }
+
+    /// <summary>
+    /// The account ID (for connect flow).
+    /// </summary>
+    public Guid? AccountId { get; set; }
+
+
+    /// <summary>
+    /// The OIDC provider name.
+    /// </summary>
+    public string? Provider { get; set; }
+
+
+    /// <summary>
+    /// The nonce for CSRF protection.
+    /// </summary>
+    public string? Nonce { get; set; }
+
+
+    /// <summary>
+    /// The device ID for the authentication request.
+    /// </summary>
+    public string? DeviceId { get; set; }
+
+
+    /// <summary>
+    /// The return URL after authentication (for login flow).
+    /// </summary>
+    public string? ReturnUrl { get; set; }
+
+
+    /// <summary>
+    /// Creates a new OidcState for a connection flow.
+    /// </summary>
+    public static OidcState ForConnection(Guid accountId, string provider, string nonce, string? deviceId = null)
+    {
+        return new OidcState
+        {
+            FlowType = OidcFlowType.Connect,
+            AccountId = accountId,
+            Provider = provider,
+            Nonce = nonce,
+            DeviceId = deviceId
+        };
+    }
+
+    /// <summary>
+    /// Creates a new OidcState for a login flow.
+    /// </summary>
+    public static OidcState ForLogin(string returnUrl = "/", string? deviceId = null)
+    {
+        return new OidcState
+        {
+            FlowType = OidcFlowType.Login,
+            ReturnUrl = returnUrl,
+            DeviceId = deviceId
+        };
+    }
+
+    /// <summary>
+    /// The version of the state format.
+    /// </summary>
+    public int Version { get; set; } = 1;
+
+    /// <summary>
+    /// Serializes the state to a JSON string for use in OIDC flows.
+    /// </summary>
+    public string Serialize()
+    {
+        return JsonSerializer.Serialize(this, new JsonSerializerOptions
+        {
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+            DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
+        });
+    }
+
+    /// <summary>
+    /// Attempts to parse a state string into an OidcState object.
+    /// </summary>
+    public static bool TryParse(string? stateString, out OidcState? state)
+    {
+        state = null;
+
+        if (string.IsNullOrEmpty(stateString))
+            return false;
+
+        try
+        {
+            // First try to parse as JSON
+            try
+            {
+                state = JsonSerializer.Deserialize<OidcState>(stateString);
+                return state != null;
+            }
+            catch (JsonException)
+            {
+                // Not a JSON string, try legacy format for backward compatibility
+                return TryParseLegacyFormat(stateString, out state);
+            }
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    private static bool TryParseLegacyFormat(string stateString, out OidcState? state)
+    {
+        state = null;
+        var parts = stateString.Split('|');
+
+        // Check for connection flow format: {accountId}|{provider}|{nonce}|{deviceId}|connect
+        if (parts.Length >= 5 &&
+            Guid.TryParse(parts[0], out var accountId) &&
+            string.Equals(parts[^1], "connect", StringComparison.OrdinalIgnoreCase))
+        {
+            state = new OidcState
+            {
+                FlowType = OidcFlowType.Connect,
+                AccountId = accountId,
+                Provider = parts[1],
+                Nonce = parts[2],
+                DeviceId = parts.Length >= 4 && !string.IsNullOrEmpty(parts[3]) ? parts[3] : null
+            };
+            return true;
+        }
+
+        // Check for login flow format: {returnUrl}|{deviceId}|login
+        if (parts.Length >= 2 &&
+            parts.Length <= 3 &&
+            (parts.Length < 3 || string.Equals(parts[^1], "login", StringComparison.OrdinalIgnoreCase)))
+        {
+            state = new OidcState
+            {
+                FlowType = OidcFlowType.Login,
+                ReturnUrl = parts[0],
+                DeviceId = parts.Length >= 2 && !string.IsNullOrEmpty(parts[1]) ? parts[1] : null
+            };
+            return true;
+        }
+
+        // Legacy format support (for backward compatibility)
+        if (parts.Length == 1)
+        {
+            state = new OidcState
+            {
+                FlowType = OidcFlowType.Login,
+                ReturnUrl = parts[0],
+                DeviceId = null
+            };
+            return true;
+        }
+
+
+        return false;
+    }
+}
+
+/// <summary>
+/// Represents the type of OIDC flow.
+/// </summary>
+public enum OidcFlowType
+{
+    /// <summary>
+    /// Login or registration flow.
+    /// </summary>
+    Login,
+
+
+    /// <summary>
+    /// Account connection flow.
+    /// </summary>
+    Connect
+}

DysonNetwork.Pass/Features/Auth/Services/OpenId/OidcUserInfo.cs

@@ -0,0 +1,49 @@
+namespace DysonNetwork.Pass.Features.Auth.OpenId;
+
+/// <summary>
+/// Represents the user information from an OIDC provider
+/// </summary>
+public class OidcUserInfo
+{
+    public string? UserId { get; set; }
+    public string? Email { get; set; }
+    public bool EmailVerified { get; set; }
+    public string FirstName { get; set; } = "";
+    public string LastName { get; set; } = "";
+    public string DisplayName { get; set; } = "";
+    public string PreferredUsername { get; set; } = "";
+    public string? ProfilePictureUrl { get; set; }
+    public string Provider { get; set; } = "";
+    public string? RefreshToken { get; set; }
+    public string? AccessToken { get; set; }
+
+    public Dictionary<string, object> ToMetadata()
+    {
+        var metadata = new Dictionary<string, object>();
+
+        if (!string.IsNullOrWhiteSpace(UserId))
+            metadata["user_id"] = UserId;
+
+        if (!string.IsNullOrWhiteSpace(Email))
+            metadata["email"] = Email;
+
+        metadata["email_verified"] = EmailVerified;
+
+        if (!string.IsNullOrWhiteSpace(FirstName))
+            metadata["first_name"] = FirstName;
+
+        if (!string.IsNullOrWhiteSpace(LastName))
+            metadata["last_name"] = LastName;
+
+        if (!string.IsNullOrWhiteSpace(DisplayName))
+            metadata["display_name"] = DisplayName;
+
+        if (!string.IsNullOrWhiteSpace(PreferredUsername))
+            metadata["preferred_username"] = PreferredUsername;
+
+        if (!string.IsNullOrWhiteSpace(ProfilePictureUrl))
+            metadata["profile_picture_url"] = ProfilePictureUrl;
+
+        return metadata;
+    }
+}