diff --git a/cmd/gateway_methods.go b/cmd/gateway_methods.go
index 2da98dea..5334b959 100644
--- a/cmd/gateway_methods.go
+++ b/cmd/gateway_methods.go
@@ -17,7 +17,7 @@ func registerAllMethods(server *gateway.Server, agents *agent.Router, sessStore
 	router := server.Router()
 
 	// Phase 1: Core methods
-	chatMethods := methods.NewChatMethods(agents, sessStore, server.RateLimiter(), msgBus)
+	chatMethods := methods.NewChatMethods(agents, sessStore, cfg, server.RateLimiter(), msgBus)
 	chatMethods.Register(router)
 	methods.NewAgentsMethods(agents, cfg, cfgPath, workspace, agentStore, contextFileInterceptor, msgBus).Register(router)
 	methods.NewSessionsMethods(sessStore, msgBus, cfg).Register(router)
diff --git a/internal/gateway/methods/access.go b/internal/gateway/methods/access.go
index 566f1817..357afc33 100644
--- a/internal/gateway/methods/access.go
+++ b/internal/gateway/methods/access.go
@@ -1,9 +1,15 @@
 package methods
 
 import (
+	"context"
 	"slices"
 
+	"github.com/nextlevelbuilder/goclaw/internal/config"
+	"github.com/nextlevelbuilder/goclaw/internal/gateway"
+	"github.com/nextlevelbuilder/goclaw/internal/i18n"
 	"github.com/nextlevelbuilder/goclaw/internal/permissions"
+	"github.com/nextlevelbuilder/goclaw/internal/store"
+	"github.com/nextlevelbuilder/goclaw/pkg/protocol"
 )
 
 // canSeeAll checks if user has full data visibility (admin role OR owner user).
@@ -16,3 +22,23 @@ func canSeeAll(role permissions.Role, ownerIDs []string, userID string) bool {
 	}
 	return false
 }
+
+// requireSessionOwner verifies the caller owns the session identified by key.
+// Returns true if the caller is authorized (owner, admin, or matching user).
+// On failure, sends an error response and returns false.
+func requireSessionOwner(ctx context.Context, sessions store.SessionStore, cfg *config.Config, client *gateway.Client, reqID string, key string) bool {
+	if canSeeAll(client.Role(), cfg.Gateway.OwnerIDs, client.UserID()) {
+		return true
+	}
+	locale := store.LocaleFromContext(ctx)
+	sess := sessions.Get(ctx, key)
+	if sess == nil {
+		client.SendResponse(protocol.NewErrorResponse(reqID, protocol.ErrNotFound, i18n.T(locale, i18n.MsgNotFound, "session", key)))
+		return false
+	}
+	if sess.UserID != client.UserID() {
+		client.SendResponse(protocol.NewErrorResponse(reqID, protocol.ErrUnauthorized, i18n.T(locale, i18n.MsgPermissionDenied, "session")))
+		return false
+	}
+	return true
+}
diff --git a/internal/gateway/methods/chat.go b/internal/gateway/methods/chat.go
index 2cb57955..3fbdfed8 100644
--- a/internal/gateway/methods/chat.go
+++ b/internal/gateway/methods/chat.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/nextlevelbuilder/goclaw/internal/agent"
 	"github.com/nextlevelbuilder/goclaw/internal/bus"
+	"github.com/nextlevelbuilder/goclaw/internal/config"
 	httpapi "github.com/nextlevelbuilder/goclaw/internal/http"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/media"
 	"github.com/nextlevelbuilder/goclaw/internal/gateway"
@@ -23,15 +24,16 @@ import (
 
 // ChatMethods handles chat.send, chat.history, chat.abort, chat.inject.
 type ChatMethods struct {
-	agents         *agent.Router
-	sessions       store.SessionStore
-	rateLimiter    *gateway.RateLimiter
-	eventBus       bus.EventPublisher
-	postTurn tools.PostTurnProcessor
+	agents      *agent.Router
+	sessions    store.SessionStore
+	cfg         *config.Config
+	rateLimiter *gateway.RateLimiter
+	eventBus    bus.EventPublisher
+	postTurn    tools.PostTurnProcessor
 }
 
-func NewChatMethods(agents *agent.Router, sess store.SessionStore, rl *gateway.RateLimiter, eventBus bus.EventPublisher) *ChatMethods {
-	return &ChatMethods{agents: agents, sessions: sess, rateLimiter: rl, eventBus: eventBus}
+func NewChatMethods(agents *agent.Router, sess store.SessionStore, cfg *config.Config, rl *gateway.RateLimiter, eventBus bus.EventPublisher) *ChatMethods {
+	return &ChatMethods{agents: agents, sessions: sess, cfg: cfg, rateLimiter: rl, eventBus: eventBus}
 }
 
 // SetPostTurnProcessor sets the post-turn processor for team task dispatch.
@@ -50,12 +52,18 @@ func (m *ChatMethods) Register(router *gateway.MethodRouter) {
 
 // handleSessionStatus returns the running state and activity for a session.
 // Used by the frontend to restore UI state after switching between sessions.
-func (m *ChatMethods) handleSessionStatus(_ context.Context, client *gateway.Client, req *protocol.RequestFrame) {
+func (m *ChatMethods) handleSessionStatus(ctx context.Context, client *gateway.Client, req *protocol.RequestFrame) {
+	locale := store.LocaleFromContext(ctx)
 	var params struct {
 		SessionKey string `json:"sessionKey"`
 	}
 	if err := json.Unmarshal(req.Params, &params); err != nil || params.SessionKey == "" {
-		client.SendResponse(protocol.NewErrorResponse(req.ID, protocol.ErrInvalidRequest, "sessionKey required"))
+		client.SendResponse(protocol.NewErrorResponse(req.ID, protocol.ErrInvalidRequest, i18n.T(locale, i18n.MsgRequired, "sessionKey")))
+		return
+	}
+
+	// Ownership check: non-admin users can only query their own sessions.
+	if !requireSessionOwner(ctx, m.sessions, m.cfg, client, req.ID, params.SessionKey) {
 		return
 	}
 
@@ -316,6 +324,11 @@ func (m *ChatMethods) handleHistory(ctx context.Context, client *gateway.Client,
 		sessionKey = sessions.BuildWSSessionKey(params.AgentID, uuid.NewString())
 	}
 
+	// Ownership check: non-admin users can only read their own session history.
+	if params.SessionKey != "" && !requireSessionOwner(ctx, m.sessions, m.cfg, client, req.ID, sessionKey) {
+		return
+	}
+
 	history := m.sessions.GetHistory(ctx, sessionKey)
 
 	// Sign file URLs before delivery — sessions store clean paths.
@@ -355,6 +368,11 @@ func (m *ChatMethods) handleInject(ctx context.Context, client *gateway.Client,
 		return
 	}
 
+	// Ownership check: non-admin users can only inject into their own sessions.
+	if !requireSessionOwner(ctx, m.sessions, m.cfg, client, req.ID, params.SessionKey) {
+		return
+	}
+
 	// Truncate label
 	if len(params.Label) > 100 {
 		params.Label = params.Label[:100]
@@ -405,6 +423,17 @@ func (m *ChatMethods) handleAbort(ctx context.Context, client *gateway.Client, r
 		return
 	}
 
+	// Non-admin users must provide sessionKey for ownership verification.
+	if params.SessionKey == "" && params.RunID != "" && !canSeeAll(client.Role(), m.cfg.Gateway.OwnerIDs, client.UserID()) {
+		client.SendResponse(protocol.NewErrorResponse(req.ID, protocol.ErrInvalidRequest, i18n.T(locale, i18n.MsgRequired, "sessionKey")))
+		return
+	}
+
+	// Ownership check: non-admin users can only abort their own sessions.
+	if params.SessionKey != "" && !requireSessionOwner(ctx, m.sessions, m.cfg, client, req.ID, params.SessionKey) {
+		return
+	}
+
 	var abortedIDs []string
 
 	if params.RunID != "" {