feat: history truncation + lazy message rehydrate (daemon + IPC)

assistant/src/__tests__/__snapshots__/ipc-snapshot.test.ts.snap

@@ -526,6 +526,14 @@ exports[`IPC message snapshots ClientMessage types conversation_search serialize
 }
 `;
 
+exports[`IPC message snapshots ClientMessage types message_content_request serializes to expected JSON 1`] = `
+{
+  "messageId": "msg-001",
+  "sessionId": "sess-001",
+  "type": "message_content_request",
+}
+`;
+
 exports[`IPC message snapshots ClientMessage types ipc_blob_probe serializes to expected JSON 1`] = `
 {
   "nonceSha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
@@ -1096,6 +1104,49 @@ exports[`IPC message snapshots ClientMessage types notification_intent_result se
 }
 `;
 
+exports[`IPC message snapshots ClientMessage types recording_status serializes to expected JSON 1`] = `
+{
+  "sessionId": "rec-001",
+  "status": "started",
+  "type": "recording_status",
+}
+`;
+
+exports[`IPC message snapshots ClientMessage types heartbeat_config serializes to expected JSON 1`] = `
+{
+  "action": "get",
+  "type": "heartbeat_config",
+}
+`;
+
+exports[`IPC message snapshots ClientMessage types heartbeat_runs_list serializes to expected JSON 1`] = `
+{
+  "type": "heartbeat_runs_list",
+}
+`;
+
+exports[`IPC message snapshots ClientMessage types heartbeat_run_now serializes to expected JSON 1`] = `
+{
+  "type": "heartbeat_run_now",
+}
+`;
+
+exports[`IPC message snapshots ClientMessage types heartbeat_checklist_read serializes to expected JSON 1`] = `
+{
+  "type": "heartbeat_checklist_read",
+}
+`;
+
+exports[`IPC message snapshots ClientMessage types heartbeat_checklist_write serializes to expected JSON 1`] = `
+{
+  "content": 
+"- [ ] Check email
+- [ ] Review PRs"
+,
+  "type": "heartbeat_checklist_write",
+}
+`;
+
 exports[`IPC message snapshots ServerMessage types auth_result serializes to expected JSON 1`] = `
 {
   "success": true,
@@ -1308,6 +1359,24 @@ exports[`IPC message snapshots ServerMessage types conversation_search_response
 }
 `;
 
+exports[`IPC message snapshots ServerMessage types message_content_response serializes to expected JSON 1`] = `
+{
+  "messageId": "msg-001",
+  "sessionId": "sess-001",
+  "text": "Full message content here",
+  "toolCalls": [
+    {
+      "input": {
+        "command": "ls",
+      },
+      "name": "bash",
+      "result": "output",
+    },
+  ],
+  "type": "message_content_response",
+}
+`;
+
 exports[`IPC message snapshots ServerMessage types error serializes to expected JSON 1`] = `
 {
   "message": "Something went wrong",
@@ -1360,6 +1429,7 @@ exports[`IPC message snapshots ServerMessage types model_info serializes to expe
 
 exports[`IPC message snapshots ServerMessage types history_response serializes to expected JSON 1`] = `
 {
+  "hasMore": false,
   "messages": [
     {
       "role": "user",
@@ -2934,3 +3004,68 @@ exports[`IPC message snapshots ServerMessage types approved_device_remove_respon
   "type": "approved_device_remove_response",
 }
 `;
+
+exports[`IPC message snapshots ServerMessage types recording_start serializes to expected JSON 1`] = `
+{
+  "recordingId": "rec-001",
+  "type": "recording_start",
+}
+`;
+
+exports[`IPC message snapshots ServerMessage types recording_stop serializes to expected JSON 1`] = `
+{
+  "recordingId": "rec-001",
+  "type": "recording_stop",
+}
+`;
+
+exports[`IPC message snapshots ServerMessage types heartbeat_config_response serializes to expected JSON 1`] = `
+{
+  "activeHoursEnd": 17,
+  "activeHoursStart": 9,
+  "enabled": true,
+  "intervalMs": 3600000,
+  "nextRunAt": 1700003600000,
+  "success": true,
+  "type": "heartbeat_config_response",
+}
+`;
+
+exports[`IPC message snapshots ServerMessage types heartbeat_runs_list_response serializes to expected JSON 1`] = `
+{
+  "runs": [
+    {
+      "createdAt": 1700000000000,
+      "id": "hb-run-001",
+      "result": "All systems nominal",
+      "title": "Morning heartbeat",
+    },
+  ],
+  "type": "heartbeat_runs_list_response",
+}
+`;
+
+exports[`IPC message snapshots ServerMessage types heartbeat_run_now_response serializes to expected JSON 1`] = `
+{
+  "success": true,
+  "type": "heartbeat_run_now_response",
+}
+`;
+
+exports[`IPC message snapshots ServerMessage types heartbeat_checklist_response serializes to expected JSON 1`] = `
+{
+  "content": 
+"- [ ] Check email
+- [ ] Review PRs"
+,
+  "isDefault": false,
+  "type": "heartbeat_checklist_response",
+}
+`;
+
+exports[`IPC message snapshots ServerMessage types heartbeat_checklist_write_response serializes to expected JSON 1`] = `
+{
+  "success": true,
+  "type": "heartbeat_checklist_write_response",
+}
+`;

assistant/src/__tests__/ipc-snapshot.test.ts

@@ -340,6 +340,11 @@ const clientMessages: Record<ClientMessageType, ClientMessage> = {
     limit: 20,
     maxMessagesPerConversation: 3,
   },
+  message_content_request: {
+    type: 'message_content_request',
+    sessionId: 'sess-001',
+    messageId: 'msg-001',
+  },
   ipc_blob_probe: {
     type: 'ipc_blob_probe',
     probeId: 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee',
@@ -842,6 +847,13 @@ const serverMessages: Record<ServerMessageType, ServerMessage> = {
       },
     ],
   },
+  message_content_response: {
+    type: 'message_content_response',
+    sessionId: 'sess-001',
+    messageId: 'msg-001',
+    text: 'Full message content here',
+    toolCalls: [{ name: 'bash', result: 'output', input: { command: 'ls' } }],
+  },
   error: {
     type: 'error',
     message: 'Something went wrong',

assistant/src/daemon/handlers/sessions.ts

@@ -21,6 +21,7 @@ import type {
   ConversationSearchRequest,
   DeleteQueuedMessage,
   HistoryRequest,
+  MessageContentRequest,
   RegenerateRequest,
   SandboxSetRequest,
   SecretResponse,
@@ -737,17 +738,37 @@ export function handleHistoryRequest(
         })))
       : m.surfaces;
 
+    // Apply text truncation when maxTextChars is set
+    let wasTruncated = false;
+    let text = m.text;
+    if (msg.maxTextChars !== undefined && text.length > msg.maxTextChars) {
+      text = text.slice(0, msg.maxTextChars) + ' \u2026 [truncated]';
+      wasTruncated = true;
+    }
+
+    // Apply tool result truncation when maxToolResultChars is set
+    const truncatedToolCalls = msg.maxToolResultChars !== undefined && filteredToolCalls.length > 0
+      ? filteredToolCalls.map((tc) => {
+        if (tc.result !== undefined && tc.result.length > msg.maxToolResultChars!) {
+          wasTruncated = true;
+          return { ...tc, result: tc.result.slice(0, msg.maxToolResultChars!) + ' \u2026 [truncated]' };
+        }
+        return tc;
+      })
+      : filteredToolCalls;
+
     return {
       ...(m.id ? { id: m.id } : {}),
       role: m.role,
-      text: m.text,
+      text,
       timestamp: m.timestamp,
-      ...(filteredToolCalls.length > 0 ? { toolCalls: filteredToolCalls, toolCallsBeforeText: m.toolCallsBeforeText } : {}),
+      ...(truncatedToolCalls.length > 0 ? { toolCalls: truncatedToolCalls, toolCallsBeforeText: m.toolCallsBeforeText } : {}),
       ...(attachments ? { attachments } : {}),
       ...(m.textSegments.length > 0 ? { textSegments: m.textSegments } : {}),
       ...(m.contentOrder.length > 0 ? { contentOrder: m.contentOrder } : {}),
       ...(filteredSurfaces.length > 0 ? { surfaces: filteredSurfaces } : {}),
       ...(m.subagentNotification ? { subagentNotification: m.subagentNotification } : {}),
+      ...(wasTruncated ? { wasTruncated: true } : {}),
     };
   });
 
@@ -888,6 +909,45 @@ export function handleConversationSearch(
   });
 }
 
+export function handleMessageContentRequest(
+  msg: MessageContentRequest,
+  socket: net.Socket,
+  ctx: HandlerContext,
+): void {
+  const dbMessage = conversationStore.getMessageById(msg.messageId, msg.sessionId);
+  if (!dbMessage) {
+    ctx.send(socket, { type: 'error', message: `Message ${msg.messageId} not found in session ${msg.sessionId}` });
+    return;
+  }
+
+  let text: string | undefined;
+  let toolCalls: Array<{ name: string; result?: string; input?: Record<string, unknown> }> | undefined;
+
+  try {
+    const content = JSON.parse(dbMessage.content);
+    const rendered = renderHistoryContent(content);
+    text = rendered.text || undefined;
+    if (rendered.toolCalls.length > 0) {
+      toolCalls = rendered.toolCalls.map((tc) => ({
+        name: tc.name,
+        input: tc.input,
+        ...(tc.result !== undefined ? { result: tc.result } : {}),
+      }));
+    }
+  } catch {
+    // Raw text content (not JSON)
+    text = dbMessage.content || undefined;
+  }
+
+  ctx.send(socket, {
+    type: 'message_content_response',
+    sessionId: msg.sessionId,
+    messageId: msg.messageId,
+    ...(text !== undefined ? { text } : {}),
+    ...(toolCalls ? { toolCalls } : {}),
+  });
+}
+
 export const sessionHandlers = defineHandlers({
   user_message: handleUserMessage,
   confirmation_response: handleConfirmationResponse,
@@ -900,6 +960,7 @@ export const sessionHandlers = defineHandlers({
   cancel: handleCancel,
   delete_queued_message: handleDeleteQueuedMessage,
   history_request: handleHistoryRequest,
+  message_content_request: handleMessageContentRequest,
   undo: handleUndo,
   regenerate: handleRegenerate,
   usage_request: handleUsageRequest,

assistant/src/daemon/ipc-contract-inventory.json

@@ -101,6 +101,7 @@
     "integration_list",
     "ipc_blob_probe",
     "link_open_request",
+    "message_content_request",
     "model_get",
     "model_set",
     "notification_intent_result",
@@ -250,6 +251,7 @@
     "memory_recalled",
     "memory_status",
     "message_complete",
+    "message_content_response",
     "message_dequeued",
     "message_queued",
     "message_queued_deleted",

assistant/src/daemon/ipc-contract/sessions.ts

@@ -102,6 +102,24 @@ export interface HistoryRequest {
   includeSurfaceData?: boolean;
   /** Shorthand: 'light' = all include flags false (default), 'full' = all include flags true. */
   mode?: 'light' | 'full';
+  /** Truncate message text fields beyond this character limit. When omitted, full text is returned. */
+  maxTextChars?: number;
+  /** Truncate tool result strings beyond this character limit. When omitted, full results are returned. */
+  maxToolResultChars?: number;
+}
+
+export interface MessageContentRequest {
+  type: 'message_content_request';
+  sessionId: string;
+  messageId: string;
+}
+
+export interface MessageContentResponse {
+  type: 'message_content_response';
+  sessionId: string;
+  messageId: string;
+  text?: string;
+  toolCalls?: Array<{ name: string; result?: string; input?: Record<string, unknown> }>;
 }
 
 export interface UndoRequest {
@@ -276,6 +294,8 @@ export interface HistoryResponse {
       error?: string;
       conversationId?: string;
     };
+    /** True when text or tool result content was truncated due to maxTextChars/maxToolResultChars. */
+    wasTruncated?: boolean;
   }>;
   /** Whether older messages exist beyond the returned page. */
   hasMore: boolean;
@@ -362,7 +382,8 @@ export type _SessionsClientMessages =
   | SessionSwitchRequest
   | SessionRenameRequest
   | SessionsClearRequest
-  | ConversationSearchRequest;
+  | ConversationSearchRequest
+  | MessageContentRequest;
 
 export type _SessionsServerMessages =
   | AuthResult
@@ -381,4 +402,5 @@ export type _SessionsServerMessages =
   | SessionTitleUpdated
   | SessionListResponse
   | SessionsClearResponse
-  | ConversationSearchResponse;
+  | ConversationSearchResponse
+  | MessageContentResponse;

assistant/src/memory/conversation-store.ts

@@ -323,6 +323,21 @@ export function getMessages(conversationId: string): MessageRow[] {
     .map(parseMessage);
 }
 
+/** Fetch a single message by ID, optionally scoped to a specific conversation. */
+export function getMessageById(messageId: string, conversationId?: string): MessageRow | null {
+  const db = getDb();
+  const conditions = [eq(messages.id, messageId)];
+  if (conversationId) {
+    conditions.push(eq(messages.conversationId, conversationId));
+  }
+  const row = db
+    .select()
+    .from(messages)
+    .where(and(...conditions))
+    .get();
+  return row ? parseMessage(row) : null;
+}
+
 export interface PaginatedMessagesResult {
   messages: MessageRow[];
   /** Whether older messages exist beyond the returned page. */