diff --git a/internal/store/agent_store.go b/internal/store/agent_store.go
index b7e20fed..aa5e204a 100644
--- a/internal/store/agent_store.go
+++ b/internal/store/agent_store.go
@@ -311,8 +311,8 @@ type UserAgentOverrideData struct {
 	Model    string    `json:"model,omitempty"`
 }
 
-// AgentStore manages agents and access control.
-type AgentStore interface {
+// AgentCRUDStore manages core agent CRUD operations.
+type AgentCRUDStore interface {
 	Create(ctx context.Context, agent *AgentData) error
 	GetByKey(ctx context.Context, agentKey string) (*AgentData, error)
 	GetByID(ctx context.Context, id uuid.UUID) (*AgentData, error)
@@ -322,36 +322,45 @@ type AgentStore interface {
 	Update(ctx context.Context, id uuid.UUID, updates map[string]any) error
 	Delete(ctx context.Context, id uuid.UUID) error
 	List(ctx context.Context, ownerID string) ([]AgentData, error)
-	GetDefault(ctx context.Context) (*AgentData, error) // agent with is_default=true, or first available
+	GetDefault(ctx context.Context) (*AgentData, error)
+}
 
-	// Access control
+// AgentAccessStore manages agent sharing and access control.
+type AgentAccessStore interface {
 	ShareAgent(ctx context.Context, agentID uuid.UUID, userID, role, grantedBy string) error
 	RevokeShare(ctx context.Context, agentID uuid.UUID, userID string) error
 	ListShares(ctx context.Context, agentID uuid.UUID) ([]AgentShareData, error)
-	CanAccess(ctx context.Context, agentID uuid.UUID, userID string) (bool, string, error) // (allowed, role, err)
+	CanAccess(ctx context.Context, agentID uuid.UUID, userID string) (bool, string, error)
 	ListAccessible(ctx context.Context, userID string) ([]AgentData, error)
+}
 
-	// Agent-level context files
+// AgentContextStore manages agent-level and per-user context files and overrides.
+type AgentContextStore interface {
 	GetAgentContextFiles(ctx context.Context, agentID uuid.UUID) ([]AgentContextFileData, error)
 	SetAgentContextFile(ctx context.Context, agentID uuid.UUID, fileName, content string) error
-
-	// Propagate agent-level file content to all existing user instances that have this file.
-	// Returns count of updated user rows.
 	PropagateContextFile(ctx context.Context, agentID uuid.UUID, fileName string) (int, error)
-
-	// Per-user context files + overrides
 	GetUserContextFiles(ctx context.Context, agentID uuid.UUID, userID string) ([]UserContextFileData, error)
 	SetUserContextFile(ctx context.Context, agentID uuid.UUID, userID, fileName, content string) error
 	DeleteUserContextFile(ctx context.Context, agentID uuid.UUID, userID, fileName string) error
 	GetUserOverride(ctx context.Context, agentID uuid.UUID, userID string) (*UserAgentOverrideData, error)
 	SetUserOverride(ctx context.Context, override *UserAgentOverrideData) error
+}
 
-	// User-agent profiles + instances
+// AgentProfileStore manages user-agent profiles and instances.
+type AgentProfileStore interface {
 	GetOrCreateUserProfile(ctx context.Context, agentID uuid.UUID, userID, workspace, channel string) (isNew bool, effectiveWorkspace string, err error)
 	EnsureUserProfile(ctx context.Context, agentID uuid.UUID, userID string) error
 	ListUserInstances(ctx context.Context, agentID uuid.UUID) ([]UserInstanceData, error)
 	UpdateUserProfileMetadata(ctx context.Context, agentID uuid.UUID, userID string, metadata map[string]string) error
+}
 
+// AgentStore composes all agent sub-interfaces for backward compatibility.
+// New code should depend on the specific sub-interface it needs.
+type AgentStore interface {
+	AgentCRUDStore
+	AgentAccessStore
+	AgentContextStore
+	AgentProfileStore
 }
 
 // UserInstanceData represents a user instance for a predefined agent.
diff --git a/internal/store/session_store.go b/internal/store/session_store.go
index 80ac9797..bf2018b4 100644
--- a/internal/store/session_store.go
+++ b/internal/store/session_store.go
@@ -86,10 +86,9 @@ type SessionListRichResult struct {
 	Total    int               `json:"total"`
 }
 
-// SessionStore manages conversation sessions.
-type SessionStore interface {
+// SessionCoreStore manages session lifecycle, messages, and history.
+type SessionCoreStore interface {
 	GetOrCreate(ctx context.Context, key string) *SessionData
-	// Get returns the session if it exists (cache or DB), nil otherwise. Never creates.
 	Get(ctx context.Context, key string) *SessionData
 	AddMessage(ctx context.Context, key string, msg providers.Message)
 	GetHistory(ctx context.Context, key string) []providers.Message
@@ -98,6 +97,15 @@ type SessionStore interface {
 	GetLabel(ctx context.Context, key string) string
 	SetLabel(ctx context.Context, key, label string)
 	SetAgentInfo(ctx context.Context, key string, agentUUID uuid.UUID, userID string)
+	TruncateHistory(ctx context.Context, key string, keepLast int)
+	SetHistory(ctx context.Context, key string, msgs []providers.Message)
+	Reset(ctx context.Context, key string)
+	Delete(ctx context.Context, key string) error
+	Save(ctx context.Context, key string) error
+}
+
+// SessionMetadataStore manages session metadata, token tracking, and calibration.
+type SessionMetadataStore interface {
 	UpdateMetadata(ctx context.Context, key, model, provider, channel string)
 	AccumulateTokens(ctx context.Context, key string, input, output int64)
 	IncrementCompaction(ctx context.Context, key string)
@@ -111,13 +119,20 @@ type SessionStore interface {
 	GetContextWindow(ctx context.Context, key string) int
 	SetLastPromptTokens(ctx context.Context, key string, tokens, msgCount int)
 	GetLastPromptTokens(ctx context.Context, key string) (tokens, msgCount int)
-	TruncateHistory(ctx context.Context, key string, keepLast int)
-	SetHistory(ctx context.Context, key string, msgs []providers.Message)
-	Reset(ctx context.Context, key string)
-	Delete(ctx context.Context, key string) error
+}
+
+// SessionListingStore manages session listing, search, and discovery.
+type SessionListingStore interface {
 	List(ctx context.Context, agentID string) []SessionInfo
 	ListPaged(ctx context.Context, opts SessionListOpts) SessionListResult
 	ListPagedRich(ctx context.Context, opts SessionListOpts) SessionListRichResult
-	Save(ctx context.Context, key string) error
 	LastUsedChannel(ctx context.Context, agentID string) (channel, chatID string)
 }
+
+// SessionStore composes all session sub-interfaces for backward compatibility.
+// New code should depend on the specific sub-interface it needs.
+type SessionStore interface {
+	SessionCoreStore
+	SessionMetadataStore
+	SessionListingStore
+}