diff --git a/DysonNetwork.Sphere/ActivityPub/ActivityPubDiscoveryService.cs b/DysonNetwork.Sphere/ActivityPub/ActivityPubDiscoveryService.cs
new file mode 100644
index 0000000..d3c4962
--- /dev/null
+++ b/DysonNetwork.Sphere/ActivityPub/ActivityPubDiscoveryService.cs
@@ -0,0 +1,255 @@
+using DysonNetwork.Shared.Models;
+using Microsoft.EntityFrameworkCore;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+
+namespace DysonNetwork.Sphere.ActivityPub;
+
+public class ActivityPubDiscoveryService(
+    AppDatabase db,
+    IHttpClientFactory httpClientFactory,
+    IConfiguration configuration,
+    ILogger<ActivityPubDiscoveryService> logger
+)
+{
+    private string Domain => configuration["ActivityPub:Domain"] ?? "localhost";
+    private HttpClient HttpClient => httpClientFactory.CreateClient();
+
+    private static readonly Regex HandlePattern = new(@"^@?(\w+)@([\w.-]+)$", RegexOptions.Compiled);
+
+    public async Task<SnFediverseActor?> DiscoverActorAsync(string query)
+    {
+        var (username, domain) = ParseHandle(query);
+        if (username == null || domain == null)
+            return null;
+
+        var actorUri = await GetActorUriFromWebfingerAsync(username, domain);
+        if (actorUri == null)
+            return null;
+
+        return await FetchAndStoreActorAsync(actorUri);
+    }
+
+    public async Task<List<SnFediverseActor>> SearchActorsAsync(
+        string query,
+        int limit = 20,
+        bool includeRemoteDiscovery = true
+    )
+    {
+        var localResults = await db.FediverseActors
+            .Where(a =>
+                a.Username.Contains(query) ||
+                a.DisplayName != null && a.DisplayName.Contains(query))
+            .OrderByDescending(a => a.LastActivityAt ?? a.CreatedAt)
+            .Take(limit)
+            .ToListAsync();
+
+        if (!includeRemoteDiscovery)
+            return localResults;
+
+        var (username, domain) = ParseHandle(query);
+        if (username != null && domain != null)
+        {
+            var actorUri = await GetActorUriFromWebfingerAsync(username, domain);
+            if (actorUri != null)
+            {
+                var remoteActor = await FetchAndStoreActorAsync(actorUri);
+                if (remoteActor != null && !localResults.Any(a => a.Uri == actorUri))
+                {
+                    var combined = new List<SnFediverseActor>(localResults) { remoteActor };
+                    return combined.Take(limit).ToList();
+                }
+            }
+        }
+
+        return localResults;
+    }
+
+    private (string? username, string? domain) ParseHandle(string query)
+    {
+        var match = HandlePattern.Match(query.Trim());
+        if (!match.Success)
+            return (null, null);
+
+        return (match.Groups[1].Value, match.Groups[2].Value);
+    }
+
+    private async Task<string?> GetActorUriFromWebfingerAsync(string username, string domain)
+    {
+        if (domain == Domain)
+            return null;
+
+        try
+        {
+            var webfingerUrl = $"https://{domain}/.well-known/webfinger?resource=acct:{username}@{domain}";
+            logger.LogInformation("Querying Webfinger: {Url}", webfingerUrl);
+
+            var response = await HttpClient.GetAsync(webfingerUrl);
+            if (!response.IsSuccessStatusCode)
+            {
+                logger.LogWarning("Webfinger request failed: {Url} - {StatusCode}", webfingerUrl, response.StatusCode);
+                return null;
+            }
+
+            var json = await response.Content.ReadAsStringAsync();
+            var webfingerData = JsonSerializer.Deserialize<WebFingerResponse>(json);
+
+            if (webfingerData?.Links == null)
+            {
+                logger.LogWarning("Invalid Webfinger response from {Url}", webfingerUrl);
+                return null;
+            }
+
+            var selfLink = webfingerData.Links.FirstOrDefault(l =>
+                l.Rel == "self" &&
+                l.Type == "application/activity+json");
+
+            if (selfLink == null)
+            {
+                logger.LogWarning("No self link found in Webfinger response from {Url}", webfingerUrl);
+                return null;
+            }
+
+            logger.LogInformation("Found actor URI via Webfinger: {ActorUri}", selfLink.Href);
+            return selfLink.Href;
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Error querying Webfinger for {Username}@{Domain}", username, domain);
+            return null;
+        }
+    }
+
+    private async Task<SnFediverseActor?> FetchAndStoreActorAsync(string actorUri)
+    {
+        var existingActor = await db.FediverseActors
+            .FirstOrDefaultAsync(a => a.Uri == actorUri);
+
+        if (existingActor != null)
+            return existingActor;
+
+        try
+        {
+            logger.LogInformation("Fetching actor: {ActorUri}", actorUri);
+
+            var response = await HttpClient.GetAsync(actorUri);
+            if (!response.IsSuccessStatusCode)
+            {
+                logger.LogWarning("Failed to fetch actor: {Url} - {StatusCode}", actorUri, response.StatusCode);
+                return null;
+            }
+
+            var json = await response.Content.ReadAsStringAsync();
+            var actorData = JsonSerializer.Deserialize<Dictionary<string, object>>(json);
+
+            if (actorData == null)
+            {
+                logger.LogWarning("Invalid actor response from {Url}", actorUri);
+                return null;
+            }
+
+            var domain = new Uri(actorUri).Host;
+            var instance = await db.FediverseInstances
+                .FirstOrDefaultAsync(i => i.Domain == domain);
+
+            if (instance == null)
+            {
+                instance = new SnFediverseInstance
+                {
+                    Domain = domain,
+                    Name = domain
+                };
+                db.FediverseInstances.Add(instance);
+                await db.SaveChangesAsync();
+            }
+
+            var actor = new SnFediverseActor
+            {
+                Uri = actorUri,
+                Username = actorData.GetValueOrDefault("preferredUsername")?.ToString() ?? ExtractUsername(actorUri),
+                DisplayName = actorData.GetValueOrDefault("name")?.ToString(),
+                Bio = actorData.GetValueOrDefault("summary")?.ToString(),
+                InboxUri = actorData.GetValueOrDefault("inbox")?.ToString(),
+                OutboxUri = actorData.GetValueOrDefault("outbox")?.ToString(),
+                FollowersUri = actorData.GetValueOrDefault("followers")?.ToString(),
+                FollowingUri = actorData.GetValueOrDefault("following")?.ToString(),
+                FeaturedUri = actorData.GetValueOrDefault("featured")?.ToString(),
+                AvatarUrl = ExtractAvatarUrl(actorData.GetValueOrDefault("icon")),
+                HeaderUrl = ExtractImageUrl(actorData.GetValueOrDefault("image")),
+                PublicKeyId = ExtractPublicKeyId(actorData.GetValueOrDefault("publicKey")),
+                PublicKey = ExtractPublicKeyPem(actorData.GetValueOrDefault("publicKey")),
+                IsBot = actorData.GetValueOrDefault("type")?.ToString() == "Service",
+                IsLocked = actorData.GetValueOrDefault("manuallyApprovesFollowers")?.ToString() == "true",
+                IsDiscoverable = actorData.GetValueOrDefault("discoverable")?.ToString() != "false",
+                InstanceId = instance.Id,
+                LastFetchedAt = NodaTime.SystemClock.Instance.GetCurrentInstant()
+            };
+
+            db.FediverseActors.Add(actor);
+            await db.SaveChangesAsync();
+
+            logger.LogInformation("Successfully fetched and stored actor: {Username}@{Domain}", actor.Username, domain);
+            return actor;
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Error fetching actor: {Uri}", actorUri);
+            return null;
+        }
+    }
+
+    private string ExtractUsername(string actorUri)
+    {
+        return actorUri.Split('/').Last();
+    }
+
+    private string? ExtractAvatarUrl(object? iconData)
+    {
+        if (iconData == null)
+            return null;
+
+        if (iconData is JsonElement element)
+        {
+            if (element.ValueKind == JsonValueKind.String)
+                return element.GetString();
+
+            if (element.TryGetProperty("url", out var urlElement))
+                return urlElement.GetString();
+        }
+
+        return iconData.ToString();
+    }
+
+    private string? ExtractImageUrl(object? imageData)
+    {
+        return ExtractAvatarUrl(imageData);
+    }
+
+    private string? ExtractPublicKeyId(object? publicKeyData)
+    {
+        if (publicKeyData == null)
+            return null;
+
+        if (publicKeyData is JsonElement element && element.TryGetProperty("id", out var idElement))
+            return idElement.GetString();
+
+        if (publicKeyData is Dictionary<string, object> dict && dict.TryGetValue("id", out var idValue))
+            return idValue?.ToString();
+
+        return null;
+    }
+
+    private string? ExtractPublicKeyPem(object? publicKeyData)
+    {
+        if (publicKeyData == null)
+            return null;
+
+        if (publicKeyData is JsonElement element && element.TryGetProperty("publicKeyPem", out var pemElement))
+            return pemElement.GetString();
+
+        if (publicKeyData is Dictionary<string, object> dict && dict.TryGetValue("publicKeyPem", out var pemValue))
+            return pemValue?.ToString();
+
+        return null;
+    }
+}
diff --git a/DysonNetwork.Sphere/ActivityPub/ActivityPubFollowController.cs b/DysonNetwork.Sphere/ActivityPub/ActivityPubFollowController.cs
index e42b2c6..f409a11 100644
--- a/DysonNetwork.Sphere/ActivityPub/ActivityPubFollowController.cs
+++ b/DysonNetwork.Sphere/ActivityPub/ActivityPubFollowController.cs
@@ -7,11 +7,12 @@ using NodaTime;
 namespace DysonNetwork.Sphere.ActivityPub;
 
 [ApiController]
-[Route("api/activitypub")]
+[Route("/api/activitypub")]
 [Authorize]
 public class ActivityPubFollowController(
     AppDatabase db,
     ActivityPubDeliveryService deliveryService,
+    ActivityPubDiscoveryService discoveryService,
     IConfiguration configuration,
     ILogger<ActivityPubFollowController> logger
 ) : ControllerBase
@@ -160,13 +161,7 @@ public class ActivityPubFollowController(
         if (string.IsNullOrWhiteSpace(query))
             return BadRequest(new { error = "Query is required" });
 
-        var actors = await db.FediverseActors
-            .Where(a => 
-                a.Username.Contains(query) || 
-                a.DisplayName != null && a.DisplayName.Contains(query))
-            .OrderByDescending(a => a.LastActivityAt ?? a.CreatedAt)
-            .Take(limit)
-            .ToListAsync();
+        var actors = await discoveryService.SearchActorsAsync(query, limit, includeRemoteDiscovery: true);
 
         return Ok(actors);
     }
diff --git a/DysonNetwork.Sphere/Startup/ServiceCollectionExtensions.cs b/DysonNetwork.Sphere/Startup/ServiceCollectionExtensions.cs
index b1c544e..780a119 100644
--- a/DysonNetwork.Sphere/Startup/ServiceCollectionExtensions.cs
+++ b/DysonNetwork.Sphere/Startup/ServiceCollectionExtensions.cs
@@ -107,6 +107,7 @@ public static class ServiceCollectionExtensions
         services.AddScoped<ActivityPubSignatureService>();
         services.AddScoped<ActivityPubActivityProcessor>();
         services.AddScoped<ActivityPubDeliveryService>();
+        services.AddScoped<ActivityPubDiscoveryService>();
         services.AddScoped<ActivityPubFollowController>();
         services.AddScoped<ActivityPubController>();