diff --git a/go.mod b/go.mod
index c97a277..a119841 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,7 @@ go 1.22
 toolchain go1.22.1
 
 require (
-	git.solsynth.dev/hydrogen/identity v0.0.0-20240406034845-44d2ec9c4ace
+	git.solsynth.dev/hydrogen/passport v0.0.0-20240504085931-7c418a3cd32f
 	github.com/go-playground/validator/v10 v10.17.0
 	github.com/gofiber/contrib/websocket v1.3.0
 	github.com/gofiber/fiber/v2 v2.52.4
@@ -59,7 +59,7 @@ require (
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/jxskiss/base62 v1.1.0 // indirect
-	github.com/klauspost/compress v1.17.7 // indirect
+	github.com/klauspost/compress v1.17.8 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.6 // indirect
 	github.com/leodido/go-urn v1.2.4 // indirect
 	github.com/lithammer/shortuuid/v4 v4.0.0 // indirect
diff --git a/go.sum b/go.sum
index e7b1340..6fb4d05 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-git.solsynth.dev/hydrogen/identity v0.0.0-20240406034845-44d2ec9c4ace h1:bXbBjM56vA3BxfyuD0IrlJabpVx5bLi4qCv3/RsPa1c=
-git.solsynth.dev/hydrogen/identity v0.0.0-20240406034845-44d2ec9c4ace/go.mod h1:GxcduEpQWQ2mO37A9uRtseS680uMLi957GDywRBAJHg=
+git.solsynth.dev/hydrogen/passport v0.0.0-20240504085931-7c418a3cd32f h1:sKrQrKZc5C+dwefRsnc0uAGttzpSUWXUBoFaCXLkaTo=
+git.solsynth.dev/hydrogen/passport v0.0.0-20240504085931-7c418a3cd32f/go.mod h1:3JRFPtf0dXRk2UQ1yVIgIspNfytM2yLBeBePJChgLZE=
 github.com/andybalholm/brotli v1.1.0 h1:eLKJA0d02Lf0mVpIDgYnqXcUn0GqVmEFny3VuID1U3M=
 github.com/andybalholm/brotli v1.1.0/go.mod h1:sms7XGricyQI9K10gOSf56VKKWS4oLer58Q+mhRPtnY=
 github.com/benbjohnson/clock v1.3.5 h1:VvXlSJBzZpA/zum6Sj74hxwYI2DIxRWuNIoXAzHZz5o=
@@ -119,8 +119,8 @@ github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnr
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/jxskiss/base62 v1.1.0 h1:A5zbF8v8WXx2xixnAKD2w+abC+sIzYJX+nxmhA6HWFw=
 github.com/jxskiss/base62 v1.1.0/go.mod h1:HhWAlUXvxKThfOlZbcuFzsqwtF5TcqS9ru3y5GfjWAc=
-github.com/klauspost/compress v1.17.7 h1:ehO88t2UGzQK66LMdE8tibEd1ErmzZjNEqWkjLAKQQg=
-github.com/klauspost/compress v1.17.7/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
+github.com/klauspost/compress v1.17.8 h1:YcnTYrq7MikUT7k0Yb5eceMmALQPYBW/Xltxn0NAMnU=
+github.com/klauspost/compress v1.17.8/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/klauspost/cpuid/v2 v2.2.6 h1:ndNyv040zDGIDh8thGkXYjnFtiN02M1PVVF+JE/48xc=
 github.com/klauspost/cpuid/v2 v2.2.6/go.mod h1:Lcz8mBdAVJIBVzewtcLocK12l3Y+JytZYpaMropDUws=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
diff --git a/pkg/database/migrator.go b/pkg/database/migrator.go
index 876f5ec..535265f 100644
--- a/pkg/database/migrator.go
+++ b/pkg/database/migrator.go
@@ -7,6 +7,7 @@ import (
 
 var DatabaseAutoActionRange = []any{
 	&models.Account{},
+	&models.Realm{},
 	&models.Channel{},
 	&models.ChannelMember{},
 	&models.Call{},
diff --git a/pkg/grpc/client.go b/pkg/grpc/client.go
index c882dc8..3a11c0f 100644
--- a/pkg/grpc/client.go
+++ b/pkg/grpc/client.go
@@ -1,13 +1,14 @@
 package grpc
 
 import (
-	idpb "git.solsynth.dev/hydrogen/identity/pkg/grpc/proto"
+	idpb "git.solsynth.dev/hydrogen/passport/pkg/grpc/proto"
 	"google.golang.org/grpc/credentials/insecure"
 
 	"github.com/spf13/viper"
 	"google.golang.org/grpc"
 )
 
+var Realms idpb.RealmsClient
 var Friendships idpb.FriendshipsClient
 var Notify idpb.NotifyClient
 var Auth idpb.AuthClient
@@ -17,6 +18,7 @@ func ConnectPassport() error {
 	if conn, err := grpc.Dial(addr, grpc.WithTransportCredentials(insecure.NewCredentials())); err != nil {
 		return err
 	} else {
+		Realms = idpb.NewRealmsClient(conn)
 		Friendships = idpb.NewFriendshipsClient(conn)
 		Notify = idpb.NewNotifyClient(conn)
 		Auth = idpb.NewAuthClient(conn)
diff --git a/pkg/models/channels.go b/pkg/models/channels.go
index ee6dff3..400af2d 100644
--- a/pkg/models/channels.go
+++ b/pkg/models/channels.go
@@ -10,7 +10,7 @@ const (
 type Channel struct {
 	BaseModel
 
-	Alias       string          `json:"alias" gorm:"uniqueIndex"`
+	Alias       string          `json:"alias"`
 	Name        string          `json:"name"`
 	Description string          `json:"description"`
 	Members     []ChannelMember `json:"members"`
@@ -19,7 +19,7 @@ type Channel struct {
 	Type        ChannelType     `json:"type"`
 	Account     Account         `json:"account"`
 	AccountID   uint            `json:"account_id"`
-	RealmID     uint            `json:"realm_id"`
+	RealmID     *uint           `json:"realm_id"`
 }
 
 type NotifyLevel = int8
diff --git a/pkg/models/realms.go b/pkg/models/realms.go
new file mode 100644
index 0000000..01269af
--- /dev/null
+++ b/pkg/models/realms.go
@@ -0,0 +1,15 @@
+package models
+
+// Realm profiles basically fetched from Hydrogen.Passport
+// But cache at here for better usage and database relations
+type Realm struct {
+	BaseModel
+
+	Alias       string    `json:"alias"`
+	Name        string    `json:"name"`
+	Description string    `json:"description"`
+	Channels    []Channel `json:"channels"`
+	IsPublic    bool      `json:"is_public"`
+	IsCommunity bool      `json:"is_community"`
+	ExternalID  uint      `json:"external_id"`
+}
diff --git a/pkg/server/auth.go b/pkg/server/auth.go
index 19d80af..b6597c0 100644
--- a/pkg/server/auth.go
+++ b/pkg/server/auth.go
@@ -3,14 +3,13 @@ package server
 import (
 	"strings"
 
-	"git.solsynth.dev/hydrogen/messaging/pkg/security"
 	"git.solsynth.dev/hydrogen/messaging/pkg/services"
 	"github.com/gofiber/fiber/v2"
 )
 
 func authMiddleware(c *fiber.Ctx) error {
 	var token string
-	if cookie := c.Cookies(security.CookieAccessKey); len(cookie) > 0 {
+	if cookie := c.Cookies(services.CookieAccessKey); len(cookie) > 0 {
 		token = cookie
 	}
 	if header := c.Get(fiber.HeaderAuthorization); len(header) > 0 {
@@ -42,10 +41,10 @@ func authFunc(c *fiber.Ctx, overrides ...string) error {
 		}
 	}
 
-	rtk := c.Cookies(security.CookieRefreshKey)
+	rtk := c.Cookies(services.CookieRefreshKey)
 	if user, atk, rtk, err := services.Authenticate(token, rtk); err == nil {
 		if atk != token {
-			security.SetJwtCookieSet(c, atk, rtk)
+			services.SetJwtCookieSet(c, atk, rtk)
 		}
 		c.Locals("principal", user)
 		return nil
diff --git a/pkg/server/channel_members_api.go b/pkg/server/channel_members_api.go
index 0efb3cf..9c17264 100644
--- a/pkg/server/channel_members_api.go
+++ b/pkg/server/channel_members_api.go
@@ -1,6 +1,7 @@
 package server
 
 import (
+	"fmt"
 	"git.solsynth.dev/hydrogen/messaging/pkg/database"
 	"git.solsynth.dev/hydrogen/messaging/pkg/models"
 	"git.solsynth.dev/hydrogen/messaging/pkg/services"
@@ -22,7 +23,7 @@ func listChannelMembers(c *fiber.Ctx) error {
 	}
 }
 
-func inviteChannel(c *fiber.Ctx) error {
+func addChannelMember(c *fiber.Ctx) error {
 	user := c.Locals("principal").(models.Account)
 	alias := c.Params("channel")
 
@@ -49,14 +50,14 @@ func inviteChannel(c *fiber.Ctx) error {
 		return fiber.NewError(fiber.StatusNotFound, err.Error())
 	}
 
-	if err := services.InviteChannelMember(account, channel); err != nil {
+	if err := services.AddChannelMemberWithCheck(account, channel); err != nil {
 		return fiber.NewError(fiber.StatusBadRequest, err.Error())
 	} else {
 		return c.SendStatus(fiber.StatusOK)
 	}
 }
 
-func kickChannel(c *fiber.Ctx) error {
+func removeChannelMember(c *fiber.Ctx) error {
 	user := c.Locals("principal").(models.Account)
 	alias := c.Params("channel")
 
@@ -124,6 +125,34 @@ func editChannelMembership(c *fiber.Ctx) error {
 	}
 }
 
+func joinChannel(c *fiber.Ctx) error {
+	user := c.Locals("principal").(models.Account)
+	alias := c.Params("channel")
+
+	var channel models.Channel
+	if err := database.C.Where(&models.Channel{
+		Alias: alias,
+	}).First(&channel).Error; err != nil {
+		return fiber.NewError(fiber.StatusNotFound, err.Error())
+	} else if _, _, err := services.GetAvailableChannel(channel.ID, user); err == nil {
+		return fiber.NewError(fiber.StatusBadRequest, "you already joined the channel")
+	} else if channel.RealmID == nil {
+		return fiber.NewError(fiber.StatusBadRequest, "you was impossible to join a channel without related realm")
+	}
+
+	if realm, err := services.GetRealm(channel.ID); err != nil {
+		return fiber.NewError(fiber.StatusInternalServerError, fmt.Sprintf("invalid channel, related realm was not found: %v", err))
+	} else if _, err := services.GetRealmMember(realm.ID, user.ExternalID); err != nil {
+		return fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("you are not a part of the realm: %v", err))
+	}
+
+	if err := services.AddChannelMember(user, channel); err != nil {
+		return fiber.NewError(fiber.StatusBadRequest, err.Error())
+	} else {
+		return c.SendStatus(fiber.StatusOK)
+	}
+}
+
 func leaveChannel(c *fiber.Ctx) error {
 	user := c.Locals("principal").(models.Account)
 	alias := c.Params("channel")
diff --git a/pkg/server/messages_api.go b/pkg/server/messages_api.go
index 71d7b8b..4a4653d 100644
--- a/pkg/server/messages_api.go
+++ b/pkg/server/messages_api.go
@@ -9,6 +9,7 @@ import (
 )
 
 func listMessage(c *fiber.Ctx) error {
+	user := c.Locals("principal").(models.Account)
 	take := c.QueryInt("take", 0)
 	offset := c.QueryInt("offset", 0)
 	alias := c.Params("channel")
@@ -16,6 +17,8 @@ func listMessage(c *fiber.Ctx) error {
 	channel, err := services.GetChannelWithAlias(alias)
 	if err != nil {
 		return fiber.NewError(fiber.StatusNotFound, err.Error())
+	} else if _, _, err := services.GetAvailableChannel(channel.ID, user); err != nil {
+		return fiber.NewError(fiber.StatusForbidden, fmt.Sprintf("you need join the channel before you read the messages: %v", err))
 	}
 
 	count := services.CountMessage(channel)
@@ -30,7 +33,7 @@ func listMessage(c *fiber.Ctx) error {
 	})
 }
 
-func newTextMessage(c *fiber.Ctx) error {
+func newMessage(c *fiber.Ctx) error {
 	user := c.Locals("principal").(models.Account)
 	alias := c.Params("channel")
 
diff --git a/pkg/server/startup.go b/pkg/server/startup.go
index de7f6ce..cf328cf 100644
--- a/pkg/server/startup.go
+++ b/pkg/server/startup.go
@@ -88,12 +88,13 @@ func NewServer() {
 
 			channels.Get("/:channel/members", listChannelMembers)
 			channels.Put("/:channel/members", authMiddleware, editChannelMembership)
-			channels.Post("/:channel/invite", authMiddleware, inviteChannel)
-			channels.Post("/:channel/kick", authMiddleware, kickChannel)
-			channels.Post("/:channel/leave", authMiddleware, leaveChannel)
+			channels.Post("/:channel/members", authMiddleware, addChannelMember)
+			channels.Post("/:channel/members/me", authMiddleware, joinChannel)
+			channels.Delete("/:channel/members", authMiddleware, removeChannelMember)
+			channels.Delete("/:channel/members/me", authMiddleware, leaveChannel)
 
-			channels.Get("/:channel/messages", listMessage)
-			channels.Post("/:channel/messages", authMiddleware, newTextMessage)
+			channels.Get("/:channel/messages", authMiddleware, listMessage)
+			channels.Post("/:channel/messages", authMiddleware, newMessage)
 			channels.Put("/:channel/messages/:messageId", authMiddleware, editMessage)
 			channels.Delete("/:channel/messages/:messageId", authMiddleware, deleteMessage)
 
diff --git a/pkg/services/accounts.go b/pkg/services/accounts.go
index 2db5c87..5a2e6f1 100644
--- a/pkg/services/accounts.go
+++ b/pkg/services/accounts.go
@@ -5,9 +5,9 @@ import (
 	"git.solsynth.dev/hydrogen/messaging/pkg/database"
 	"time"
 
-	"git.solsynth.dev/hydrogen/identity/pkg/grpc/proto"
 	"git.solsynth.dev/hydrogen/messaging/pkg/grpc"
 	"git.solsynth.dev/hydrogen/messaging/pkg/models"
+	"git.solsynth.dev/hydrogen/passport/pkg/grpc/proto"
 	"github.com/spf13/viper"
 )
 
diff --git a/pkg/services/auth.go b/pkg/services/auth.go
index a79f1df..1620aba 100644
--- a/pkg/services/auth.go
+++ b/pkg/services/auth.go
@@ -7,10 +7,10 @@ import (
 	"reflect"
 	"time"
 
-	"git.solsynth.dev/hydrogen/identity/pkg/grpc/proto"
 	"git.solsynth.dev/hydrogen/messaging/pkg/database"
 	"git.solsynth.dev/hydrogen/messaging/pkg/grpc"
 	"git.solsynth.dev/hydrogen/messaging/pkg/models"
+	"git.solsynth.dev/hydrogen/passport/pkg/grpc/proto"
 	"gorm.io/gorm"
 )
 
diff --git a/pkg/services/channel_members.go b/pkg/services/channel_members.go
index 3617504..7165e8e 100644
--- a/pkg/services/channel_members.go
+++ b/pkg/services/channel_members.go
@@ -19,7 +19,7 @@ func ListChannelMember(channelId uint) ([]models.ChannelMember, error) {
 	return members, nil
 }
 
-func InviteChannelMember(user models.Account, target models.Channel) error {
+func AddChannelMemberWithCheck(user models.Account, target models.Channel) error {
 	if _, err := GetAccountFriend(user.ID, target.AccountID, 1); err != nil {
 		return fmt.Errorf("you only can invite your friends to your channel")
 	}
diff --git a/pkg/security/encryptor.go b/pkg/services/encryptor.go
similarity index 94%
rename from pkg/security/encryptor.go
rename to pkg/services/encryptor.go
index 6cebde0..8700731 100644
--- a/pkg/security/encryptor.go
+++ b/pkg/services/encryptor.go
@@ -1,4 +1,4 @@
-package security
+package services
 
 import "golang.org/x/crypto/bcrypt"
 
diff --git a/pkg/security/jwt.go b/pkg/services/jwt.go
similarity index 99%
rename from pkg/security/jwt.go
rename to pkg/services/jwt.go
index 450a16e..77b5b22 100644
--- a/pkg/security/jwt.go
+++ b/pkg/services/jwt.go
@@ -1,4 +1,4 @@
-package security
+package services
 
 import (
 	"fmt"
diff --git a/pkg/services/realms.go b/pkg/services/realms.go
new file mode 100644
index 0000000..1a39999
--- /dev/null
+++ b/pkg/services/realms.go
@@ -0,0 +1,82 @@
+package services
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"git.solsynth.dev/hydrogen/messaging/pkg/database"
+	"git.solsynth.dev/hydrogen/messaging/pkg/grpc"
+	"git.solsynth.dev/hydrogen/messaging/pkg/models"
+	"git.solsynth.dev/hydrogen/passport/pkg/grpc/proto"
+	"github.com/samber/lo"
+	"gorm.io/gorm"
+)
+
+func GetRealm(id uint) (models.Realm, error) {
+	var realm models.Realm
+	response, err := grpc.Realms.GetRealm(context.Background(), &proto.RealmLookupRequest{
+		Id: lo.ToPtr(uint64(id)),
+	})
+	if err != nil {
+		return realm, err
+	}
+	return LinkRealm(response)
+}
+
+func GetRealmWithAlias(alias string) (models.Realm, error) {
+	var realm models.Realm
+	response, err := grpc.Realms.GetRealm(context.Background(), &proto.RealmLookupRequest{
+		Alias: &alias,
+	})
+	if err != nil {
+		return realm, err
+	}
+	return LinkRealm(response)
+}
+
+func GetRealmMember(realmId uint, userId uint) (*proto.RealmMemberResponse, error) {
+	response, err := grpc.Realms.GetRealmMember(context.Background(), &proto.RealmMemberLookupRequest{
+		RealmId: uint64(realmId),
+		UserId:  lo.ToPtr(uint64(userId)),
+	})
+	if err != nil {
+		return nil, err
+	} else {
+		return response, nil
+	}
+}
+
+func ListRealmMember(realmId uint) ([]*proto.RealmMemberResponse, error) {
+	response, err := grpc.Realms.ListRealmMember(context.Background(), &proto.RealmMemberLookupRequest{
+		RealmId: uint64(realmId),
+	})
+	if err != nil {
+		return nil, err
+	} else {
+		return response.Data, nil
+	}
+}
+
+func LinkRealm(info *proto.RealmResponse) (models.Realm, error) {
+	var realm models.Realm
+	if info == nil {
+		return realm, fmt.Errorf("remote realm info was not found")
+	}
+	if err := database.C.Where(&models.Realm{
+		ExternalID: uint(info.Id),
+	}).First(&realm).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			realm = models.Realm{
+				Alias:       info.Alias,
+				Name:        info.Name,
+				Description: info.Description,
+				IsPublic:    info.IsPublic,
+				IsCommunity: info.IsCommunity,
+				ExternalID:  uint(info.Id),
+			}
+			return realm, database.C.Save(&realm).Error
+		}
+		return realm, err
+	}
+	return realm, nil
+}