feat(chatd): persist last_error on chats table (#22436)

Adds a nullable `last_error` column to the `chats` table so error
reasons survive page reloads.

**Backend:**
- Migration adds `last_error TEXT` (nullable) to chats
- `UpdateChatStatus` writes the error reason when status transitions to
`error`, clears it (NULL) on recovery
- `convertChat` maps `sql.NullString` to `*string` in the SDK

**Frontend:**
- Sidebar falls back to `chat.last_error` when no stream error reason is
cached
- Chat detail page does the same for `persistedErrorReason`
- Fixtures updated for new required field

coderd/chatd/chatd.go

@@ -478,6 +478,7 @@ func (p *Server) EditMessage(
 			WorkerID:    uuid.NullUUID{},
 			StartedAt:   sql.NullTime{},
 			HeartbeatAt: sql.NullTime{},
+			LastError:   sql.NullString{},
 		})
 		if err != nil {
 			return xerrors.Errorf("set chat pending: %w", err)
@@ -739,6 +740,7 @@ func setChatPendingWithStore(
 		WorkerID:    uuid.NullUUID{},
 		StartedAt:   sql.NullTime{},
 		HeartbeatAt: sql.NullTime{},
+		LastError:   sql.NullString{},
 	})
 	if err != nil {
 		return database.Chat{}, xerrors.Errorf("set chat pending: %w", err)
@@ -753,6 +755,7 @@ func (p *Server) setChatWaiting(ctx context.Context, chatID uuid.UUID) (database
 		WorkerID:    uuid.NullUUID{},
 		StartedAt:   sql.NullTime{},
 		HeartbeatAt: sql.NullTime{},
+		LastError:   sql.NullString{},
 	})
 	if err != nil {
 		return database.Chat{}, err
@@ -810,6 +813,7 @@ func insertUserMessageAndSetPending(
 		WorkerID:    uuid.NullUUID{},
 		StartedAt:   sql.NullTime{},
 		HeartbeatAt: sql.NullTime{},
+		LastError:   sql.NullString{},
 	})
 	if err != nil {
 		return database.ChatMessage{}, database.Chat{}, xerrors.Errorf("set chat pending: %w", err)
@@ -1622,8 +1626,9 @@ func (p *Server) processChat(ctx context.Context, chat database.Chat) {
 		Valid: true,
 	})
 
-	// Determine the final status to set when we're done.
+	// Determine the final status and last error to set when we're done.
 	status := database.ChatStatusWaiting
+	lastError := ""
 	remainingQueuedMessages := []database.ChatQueuedMessage{}
 	shouldPublishQueueUpdate := false
 
@@ -1636,7 +1641,8 @@ func (p *Server) processChat(ctx context.Context, chat database.Chat) {
 		// Handle panics gracefully.
 		if r := recover(); r != nil {
 			logger.Error(cleanupCtx, "panic during chat processing", slog.F("panic", r))
-			p.publishError(chat.ID, panicFailureReason(r))
+			lastError = panicFailureReason(r)
+			p.publishError(chat.ID, lastError)
 			status = database.ChatStatusError
 		}
 
@@ -1707,6 +1713,7 @@ func (p *Server) processChat(ctx context.Context, chat database.Chat) {
 				WorkerID:    uuid.NullUUID{},
 				StartedAt:   sql.NullTime{},
 				HeartbeatAt: sql.NullTime{},
+				LastError:   sql.NullString{String: lastError, Valid: lastError != ""},
 			})
 			return updateErr
 		}, nil)
@@ -1746,7 +1753,8 @@ func (p *Server) processChat(ctx context.Context, chat database.Chat) {
 		}
 		logger.Error(ctx, "failed to process chat", slog.Error(err))
 		if reason, ok := processingFailureReason(err); ok {
-			p.publishError(chat.ID, reason)
+			lastError = reason
+			p.publishError(chat.ID, lastError)
 		}
 		status = database.ChatStatusError
 		return
@@ -2458,6 +2466,7 @@ func (p *Server) recoverStaleChats(ctx context.Context) {
 			WorkerID:    uuid.NullUUID{},
 			StartedAt:   sql.NullTime{},
 			HeartbeatAt: sql.NullTime{},
+			LastError:   sql.NullString{},
 		})
 		if err != nil {
 			p.logger.Error(ctx, "failed to recover stale chat",

coderd/chatd/chatd_test.go

@@ -577,6 +577,61 @@ func TestWaitingChatsAreNotRecoveredAsStale(t *testing.T) {
 		"waiting chat should not be modified by stale recovery")
 }
 
+func TestUpdateChatStatusPersistsLastError(t *testing.T) {
+	t.Parallel()
+
+	db, ps := dbtestutil.NewDB(t)
+	_ = newTestServer(t, db, ps, uuid.New())
+
+	ctx := testutil.Context(t, testutil.WaitLong)
+	user, model := seedChatDependencies(ctx, t, db)
+
+	chat, err := db.InsertChat(ctx, database.InsertChatParams{
+		OwnerID:           user.ID,
+		Title:             "error-persisted",
+		LastModelConfigID: model.ID,
+	})
+	require.NoError(t, err)
+
+	// Simulate a chat that failed with an error.
+	errorMessage := "stream response: status 500: internal server error"
+	chat, err = db.UpdateChatStatus(ctx, database.UpdateChatStatusParams{
+		ID:          chat.ID,
+		Status:      database.ChatStatusError,
+		WorkerID:    uuid.NullUUID{},
+		StartedAt:   sql.NullTime{},
+		HeartbeatAt: sql.NullTime{},
+		LastError:   sql.NullString{String: errorMessage, Valid: true},
+	})
+	require.NoError(t, err)
+	require.Equal(t, database.ChatStatusError, chat.Status)
+	require.Equal(t, sql.NullString{String: errorMessage, Valid: true}, chat.LastError)
+
+	// Verify the error is persisted when re-read from the database.
+	fromDB, err := db.GetChatByID(ctx, chat.ID)
+	require.NoError(t, err)
+	require.Equal(t, database.ChatStatusError, fromDB.Status)
+	require.Equal(t, sql.NullString{String: errorMessage, Valid: true}, fromDB.LastError)
+
+	// Verify the error is cleared when the chat transitions to a
+	// non-error status (e.g. pending after a retry).
+	chat, err = db.UpdateChatStatus(ctx, database.UpdateChatStatusParams{
+		ID:          chat.ID,
+		Status:      database.ChatStatusPending,
+		WorkerID:    uuid.NullUUID{},
+		StartedAt:   sql.NullTime{},
+		HeartbeatAt: sql.NullTime{},
+		LastError:   sql.NullString{},
+	})
+	require.NoError(t, err)
+	require.Equal(t, database.ChatStatusPending, chat.Status)
+	require.False(t, chat.LastError.Valid)
+
+	fromDB, err = db.GetChatByID(ctx, chat.ID)
+	require.NoError(t, err)
+	require.False(t, fromDB.LastError.Valid)
+}
+
 func newTestServer(
 	t *testing.T,
 	db database.Store,

coderd/chats.go

@@ -795,6 +795,7 @@ func (api *API) interruptChat(rw http.ResponseWriter, r *http.Request) {
 			WorkerID:    uuid.NullUUID{},
 			StartedAt:   sql.NullTime{},
 			HeartbeatAt: sql.NullTime{},
+			LastError:   sql.NullString{},
 		})
 		if updateErr != nil {
 			api.Logger.Error(ctx, "failed to mark chat as waiting",
@@ -2059,6 +2060,9 @@ func convertChat(c database.Chat, diffStatus *database.ChatDiffStatus) codersdk.
 		CreatedAt:         c.CreatedAt,
 		UpdatedAt:         c.UpdatedAt,
 	}
+	if c.LastError.Valid {
+		chat.LastError = &c.LastError.String
+	}
 	if c.ParentChatID.Valid {
 		parentChatID := c.ParentChatID.UUID
 		chat.ParentChatID = &parentChatID

coderd/database/dump.sql

@@ -1274,7 +1274,8 @@ CREATE TABLE chats (
     parent_chat_id uuid,
     root_chat_id uuid,
     last_model_config_id uuid NOT NULL,
-    archived boolean DEFAULT false NOT NULL
+    archived boolean DEFAULT false NOT NULL,
+    last_error text
 );
 
 CREATE TABLE connection_logs (

coderd/database/migrations/000424_chat_last_error.down.sql

@@ -0,0 +1 @@
+ALTER TABLE chats DROP COLUMN last_error;

coderd/database/migrations/000424_chat_last_error.up.sql

@@ -0,0 +1 @@
+ALTER TABLE chats ADD COLUMN last_error TEXT;

coderd/database/models.go

@@ -3886,21 +3886,22 @@ type BoundaryUsageStat struct {
 }
 
 type Chat struct {
-	ID                uuid.UUID     `db:"id" json:"id"`
-	OwnerID           uuid.UUID     `db:"owner_id" json:"owner_id"`
-	WorkspaceID       uuid.NullUUID `db:"workspace_id" json:"workspace_id"`
-	WorkspaceAgentID  uuid.NullUUID `db:"workspace_agent_id" json:"workspace_agent_id"`
-	Title             string        `db:"title" json:"title"`
-	Status            ChatStatus    `db:"status" json:"status"`
-	WorkerID          uuid.NullUUID `db:"worker_id" json:"worker_id"`
-	StartedAt         sql.NullTime  `db:"started_at" json:"started_at"`
-	HeartbeatAt       sql.NullTime  `db:"heartbeat_at" json:"heartbeat_at"`
-	CreatedAt         time.Time     `db:"created_at" json:"created_at"`
-	UpdatedAt         time.Time     `db:"updated_at" json:"updated_at"`
-	ParentChatID      uuid.NullUUID `db:"parent_chat_id" json:"parent_chat_id"`
-	RootChatID        uuid.NullUUID `db:"root_chat_id" json:"root_chat_id"`
-	LastModelConfigID uuid.UUID     `db:"last_model_config_id" json:"last_model_config_id"`
-	Archived          bool          `db:"archived" json:"archived"`
+	ID                uuid.UUID      `db:"id" json:"id"`
+	OwnerID           uuid.UUID      `db:"owner_id" json:"owner_id"`
+	WorkspaceID       uuid.NullUUID  `db:"workspace_id" json:"workspace_id"`
+	WorkspaceAgentID  uuid.NullUUID  `db:"workspace_agent_id" json:"workspace_agent_id"`
+	Title             string         `db:"title" json:"title"`
+	Status            ChatStatus     `db:"status" json:"status"`
+	WorkerID          uuid.NullUUID  `db:"worker_id" json:"worker_id"`
+	StartedAt         sql.NullTime   `db:"started_at" json:"started_at"`
+	HeartbeatAt       sql.NullTime   `db:"heartbeat_at" json:"heartbeat_at"`
+	CreatedAt         time.Time      `db:"created_at" json:"created_at"`
+	UpdatedAt         time.Time      `db:"updated_at" json:"updated_at"`
+	ParentChatID      uuid.NullUUID  `db:"parent_chat_id" json:"parent_chat_id"`
+	RootChatID        uuid.NullUUID  `db:"root_chat_id" json:"root_chat_id"`
+	LastModelConfigID uuid.UUID      `db:"last_model_config_id" json:"last_model_config_id"`
+	Archived          bool           `db:"archived" json:"archived"`
+	LastError         sql.NullString `db:"last_error" json:"last_error"`
 }
 
 type ChatDiffStatus struct {

coderd/database/queries.sql.go

@@ -2842,7 +2842,7 @@ WHERE
             1
     )
 RETURNING
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 `
 
 type AcquireChatParams struct {
@@ -2871,6 +2871,7 @@ func (q *sqlQuerier) AcquireChat(ctx context.Context, arg AcquireChatParams) (Ch
 		&i.RootChatID,
 		&i.LastModelConfigID,
 		&i.Archived,
+		&i.LastError,
 	)
 	return i, err
 }
@@ -2939,7 +2940,7 @@ func (q *sqlQuerier) DeleteChatQueuedMessage(ctx context.Context, arg DeleteChat
 
 const getChatByID = `-- name: GetChatByID :one
 SELECT
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 FROM
     chats
 WHERE
@@ -2965,12 +2966,13 @@ func (q *sqlQuerier) GetChatByID(ctx context.Context, id uuid.UUID) (Chat, error
 		&i.RootChatID,
 		&i.LastModelConfigID,
 		&i.Archived,
+		&i.LastError,
 	)
 	return i, err
 }
 
 const getChatByIDForUpdate = `-- name: GetChatByIDForUpdate :one
-SELECT id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived FROM chats WHERE id = $1::uuid FOR UPDATE
+SELECT id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error FROM chats WHERE id = $1::uuid FOR UPDATE
 `
 
 func (q *sqlQuerier) GetChatByIDForUpdate(ctx context.Context, id uuid.UUID) (Chat, error) {
@@ -2992,6 +2994,7 @@ func (q *sqlQuerier) GetChatByIDForUpdate(ctx context.Context, id uuid.UUID) (Ch
 		&i.RootChatID,
 		&i.LastModelConfigID,
 		&i.Archived,
+		&i.LastError,
 	)
 	return i, err
 }
@@ -3288,7 +3291,7 @@ func (q *sqlQuerier) GetChatQueuedMessages(ctx context.Context, chatID uuid.UUID
 
 const getChatsByOwnerID = `-- name: GetChatsByOwnerID :many
 SELECT
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 FROM
     chats
 WHERE
@@ -3323,6 +3326,7 @@ func (q *sqlQuerier) GetChatsByOwnerID(ctx context.Context, ownerID uuid.UUID) (
 			&i.RootChatID,
 			&i.LastModelConfigID,
 			&i.Archived,
+			&i.LastError,
 		); err != nil {
 			return nil, err
 		}
@@ -3339,7 +3343,7 @@ func (q *sqlQuerier) GetChatsByOwnerID(ctx context.Context, ownerID uuid.UUID) (
 
 const getStaleChats = `-- name: GetStaleChats :many
 SELECT
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 FROM
     chats
 WHERE
@@ -3374,6 +3378,7 @@ func (q *sqlQuerier) GetStaleChats(ctx context.Context, staleThreshold time.Time
 			&i.RootChatID,
 			&i.LastModelConfigID,
 			&i.Archived,
+			&i.LastError,
 		); err != nil {
 			return nil, err
 		}
@@ -3407,7 +3412,7 @@ INSERT INTO chats (
     $7::text
 )
 RETURNING
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 `
 
 type InsertChatParams struct {
@@ -3447,6 +3452,7 @@ func (q *sqlQuerier) InsertChat(ctx context.Context, arg InsertChatParams) (Chat
 		&i.RootChatID,
 		&i.LastModelConfigID,
 		&i.Archived,
+		&i.LastError,
 	)
 	return i, err
 }
@@ -3572,7 +3578,7 @@ func (q *sqlQuerier) InsertChatQueuedMessage(ctx context.Context, arg InsertChat
 
 const listChatsByRootID = `-- name: ListChatsByRootID :many
 SELECT
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 FROM
     chats
 WHERE
@@ -3606,6 +3612,7 @@ func (q *sqlQuerier) ListChatsByRootID(ctx context.Context, rootChatID uuid.UUID
 			&i.RootChatID,
 			&i.LastModelConfigID,
 			&i.Archived,
+			&i.LastError,
 		); err != nil {
 			return nil, err
 		}
@@ -3622,7 +3629,7 @@ func (q *sqlQuerier) ListChatsByRootID(ctx context.Context, rootChatID uuid.UUID
 
 const listChildChatsByParentID = `-- name: ListChildChatsByParentID :many
 SELECT
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 FROM
     chats
 WHERE
@@ -3656,6 +3663,7 @@ func (q *sqlQuerier) ListChildChatsByParentID(ctx context.Context, parentChatID
 			&i.RootChatID,
 			&i.LastModelConfigID,
 			&i.Archived,
+			&i.LastError,
 		); err != nil {
 			return nil, err
 		}
@@ -3711,7 +3719,7 @@ SET
 WHERE
     id = $2::uuid
 RETURNING
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 `
 
 type UpdateChatByIDParams struct {
@@ -3738,6 +3746,7 @@ func (q *sqlQuerier) UpdateChatByID(ctx context.Context, arg UpdateChatByIDParam
 		&i.RootChatID,
 		&i.LastModelConfigID,
 		&i.Archived,
+		&i.LastError,
 	)
 	return i, err
 }
@@ -3817,19 +3826,21 @@ SET
     worker_id = $2::uuid,
     started_at = $3::timestamptz,
     heartbeat_at = $4::timestamptz,
+    last_error = $5::text,
     updated_at = NOW()
 WHERE
-    id = $5::uuid
+    id = $6::uuid
 RETURNING
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 `
 
 type UpdateChatStatusParams struct {
-	Status      ChatStatus    `db:"status" json:"status"`
-	WorkerID    uuid.NullUUID `db:"worker_id" json:"worker_id"`
-	StartedAt   sql.NullTime  `db:"started_at" json:"started_at"`
-	HeartbeatAt sql.NullTime  `db:"heartbeat_at" json:"heartbeat_at"`
-	ID          uuid.UUID     `db:"id" json:"id"`
+	Status      ChatStatus     `db:"status" json:"status"`
+	WorkerID    uuid.NullUUID  `db:"worker_id" json:"worker_id"`
+	StartedAt   sql.NullTime   `db:"started_at" json:"started_at"`
+	HeartbeatAt sql.NullTime   `db:"heartbeat_at" json:"heartbeat_at"`
+	LastError   sql.NullString `db:"last_error" json:"last_error"`
+	ID          uuid.UUID      `db:"id" json:"id"`
 }
 
 func (q *sqlQuerier) UpdateChatStatus(ctx context.Context, arg UpdateChatStatusParams) (Chat, error) {
@@ -3838,6 +3849,7 @@ func (q *sqlQuerier) UpdateChatStatus(ctx context.Context, arg UpdateChatStatusP
 		arg.WorkerID,
 		arg.StartedAt,
 		arg.HeartbeatAt,
+		arg.LastError,
 		arg.ID,
 	)
 	var i Chat
@@ -3857,6 +3869,7 @@ func (q *sqlQuerier) UpdateChatStatus(ctx context.Context, arg UpdateChatStatusP
 		&i.RootChatID,
 		&i.LastModelConfigID,
 		&i.Archived,
+		&i.LastError,
 	)
 	return i, err
 }
@@ -3871,7 +3884,7 @@ SET
 WHERE
     id = $3::uuid
 RETURNING
-    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived
+    id, owner_id, workspace_id, workspace_agent_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error
 `
 
 type UpdateChatWorkspaceParams struct {
@@ -3899,6 +3912,7 @@ func (q *sqlQuerier) UpdateChatWorkspace(ctx context.Context, arg UpdateChatWork
 		&i.RootChatID,
 		&i.LastModelConfigID,
 		&i.Archived,
+		&i.LastError,
 	)
 	return i, err
 }

coderd/database/queries/chats.sql

@@ -266,6 +266,7 @@ SET
     worker_id = sqlc.narg('worker_id')::uuid,
     started_at = sqlc.narg('started_at')::timestamptz,
     heartbeat_at = sqlc.narg('heartbeat_at')::timestamptz,
+    last_error = sqlc.narg('last_error')::text,
     updated_at = NOW()
 WHERE
     id = @id::uuid

codersdk/chats.go

@@ -38,6 +38,7 @@ type Chat struct {
 	LastModelConfigID uuid.UUID       `json:"last_model_config_id" format:"uuid"`
 	Title             string          `json:"title"`
 	Status            ChatStatus      `json:"status"`
+	LastError         *string         `json:"last_error"`
 	DiffStatus        *ChatDiffStatus `json:"diff_status,omitempty"`
 	CreatedAt         time.Time       `json:"created_at" format:"date-time"`
 	UpdatedAt         time.Time       `json:"updated_at" format:"date-time"`

site/src/api/typesGenerated.ts

@@ -1060,6 +1060,7 @@ export interface Chat {
 	readonly last_model_config_id: string;
 	readonly title: string;
 	readonly status: ChatStatus;
+	readonly last_error: string | null;
 	readonly diff_status?: ChatDiffStatus;
 	readonly created_at: string;
 	readonly updated_at: string;

site/src/pages/AgentsPage/AgentDetail.stories.tsx

@@ -122,6 +122,7 @@ const baseChatFields = {
 	created_at: "2026-02-18T00:00:00.000Z",
 	updated_at: "2026-02-18T00:00:00.000Z",
 	archived: false,
+	last_error: null,
 } as const;
 
 // ---------------------------------------------------------------------------

site/src/pages/AgentsPage/AgentDetail.tsx

@@ -974,7 +974,9 @@ const AgentDetail: FC = () => {
 					<AgentDetailConversation
 						store={store}
 						chatID={agentId}
-						persistedErrorReason={chatErrorReasons[agentId]}
+						persistedErrorReason={
+							chatErrorReasons[agentId] || chatRecord?.last_error || undefined
+						}
 						compressionThreshold={compressionThreshold}
 						onDeleteQueuedMessage={handleDeleteQueuedMessage}
 						onPromoteQueuedMessage={handlePromoteQueuedMessage}

site/src/pages/AgentsPage/AgentDetail/ChatContext.test.tsx

@@ -113,6 +113,7 @@ const makeChat = (chatID: string): TypesGen.Chat => ({
 	created_at: "2025-01-01T00:00:00.000Z",
 	updated_at: "2025-01-01T00:00:00.000Z",
 	archived: false,
+	last_error: null,
 });
 
 const makeMessage = (

site/src/pages/AgentsPage/AgentsSidebar.stories.tsx

@@ -39,6 +39,7 @@ const buildChat = (overrides: Partial<Chat> = {}): Chat => ({
 	created_at: "2026-02-18T00:00:00.000Z",
 	updated_at: "2026-02-18T00:00:00.000Z",
 	archived: false,
+	last_error: null,
 	...overrides,
 });
 

site/src/pages/AgentsPage/AgentsSidebar.tsx

@@ -312,7 +312,9 @@ const ChatTreeNode = memo<ChatTreeNodeProps>(({ chat, isChildNode }) => {
 		modelOptions,
 	);
 	const errorReason =
-		chat.status === "error" ? chatErrorReasons[chat.id] : undefined;
+		chat.status === "error"
+			? chatErrorReasons[chat.id] || chat.last_error || undefined
+			: undefined;
 	const subtitle = errorReason || modelName;
 	const diffStatus = getChatDiffStatus(chat);
 	const hasLinkedDiffStatus = Boolean(diffStatus?.url);