fix: migrate default conversation API usage to SDK 1.7.11 pattern (#1256)

Co-authored-by: Letta Code <noreply@letta.com>

src/tests/cli/stream-resume-fallback.test.ts

@@ -85,7 +85,7 @@ describe("discoverFallbackRunIdForResume", () => {
       makeRunsListClient(runsList),
       {
         conversationId: "default",
-        resolvedConversationId: "agent-test",
+        resolvedConversationId: "default",
         agentId: "agent-test",
         requestStartedAtMs: Date.parse("2026-02-27T11:00:00.000Z"),
       },
@@ -93,7 +93,7 @@ describe("discoverFallbackRunIdForResume", () => {
 
     expect(candidate).toBe("run-agent-fallback");
     expect(calls).toEqual([
-      { conversation_id: "agent-test", agent_id: undefined },
+      { conversation_id: "default", agent_id: undefined },
       { conversation_id: undefined, agent_id: "agent-test" },
     ]);
   });

src/tests/headless/bootstrap-handler.test.ts

@@ -7,7 +7,7 @@
  * 3. Pagination fields (next_before, has_more)
  * 4. Timing fields presence
  * 5. Error path — client throws → error envelope returned
- * 6. Default conversation passes agent ID to conversations.messages.list
+ * 6. Default conversation passes conversation_id="default" with agent_id query
  * 7. Explicit conversation uses conversations.messages.list
  *
  * No network. No CLI subprocess. No process.stdout.
@@ -56,7 +56,7 @@ const BASE_CTX: BootstrapHandlerSessionContext = {
 // ─────────────────────────────────────────────────────────────────────────────
 
 describe("bootstrap_session_state routing", () => {
-  test("default conversation passes agent ID to conversations.messages.list", async () => {
+  test("default conversation passes default + agent_id to conversations.messages.list", async () => {
     const { client, convListSpy } = makeClient([
       { id: "msg-1", type: "user_message" },
     ]);
@@ -70,9 +70,11 @@ describe("bootstrap_session_state routing", () => {
 
     expect(convListSpy).toHaveBeenCalledTimes(1);
 
-    // Verify agent ID is passed as the conversation_id
-    const callArgs = (convListSpy.mock.calls[0] as unknown[])[0];
-    expect(callArgs).toBe("agent-test-123");
+    const callArgs = convListSpy.mock.calls[0] as unknown[];
+    expect(callArgs[0]).toBe("default");
+    expect((callArgs[1] as { agent_id?: string }).agent_id).toBe(
+      "agent-test-123",
+    );
   });
 
   test("named conversation uses conversations.messages.list", async () => {

src/tests/headless/list-messages-handler.test.ts

@@ -105,7 +105,7 @@ describe("handleListMessages — routing (which API is called)", () => {
     }
   });
 
-  test("omitted conversation_id + session on default → calls conversations.messages.list with agent ID", async () => {
+  test("omitted conversation_id + session on default → calls conversations.messages.list with default + agent_id", async () => {
     const { client, convListSpy } = makeClient([{ id: "msg-default-1" }]);
 
     const resp = await handleListMessages({
@@ -117,11 +117,13 @@ describe("handleListMessages — routing (which API is called)", () => {
     });
 
     expect(convListSpy).toHaveBeenCalledTimes(1);
-    expect(convListSpy.mock.calls[0]?.[0]).toBe("agent-def");
+    expect(convListSpy.mock.calls[0]?.[0]).toBe("default");
+    const opts = convListSpy.mock.calls[0]?.[1] as { agent_id?: string };
+    expect(opts.agent_id).toBe("agent-def");
     expect(resp.response.subtype).toBe("success");
   });
 
-  test("explicit agent_id + session default → conversations path uses request agent_id", async () => {
+  test("explicit agent_id + session default → conversations path uses request agent_id query", async () => {
     const { client, convListSpy } = makeClient([]);
 
     await handleListMessages({
@@ -132,7 +134,9 @@ describe("handleListMessages — routing (which API is called)", () => {
       client,
     });
 
-    expect(convListSpy.mock.calls[0]?.[0]).toBe("agent-override");
+    expect(convListSpy.mock.calls[0]?.[0]).toBe("default");
+    const opts = convListSpy.mock.calls[0]?.[1] as { agent_id?: string };
+    expect(opts.agent_id).toBe("agent-override");
   });
 });
 
@@ -176,12 +180,13 @@ describe("handleListMessages — API call arguments", () => {
       client,
     });
 
-    // Default conversation resolves to agent ID
-    expect(convListSpy.mock.calls[0]?.[0]).toBe("agent-1");
+    expect(convListSpy.mock.calls[0]?.[0]).toBe("default");
     const opts = convListSpy.mock.calls[0]?.[1] as {
+      agent_id?: string;
       limit: number;
       order: string;
     };
+    expect(opts.agent_id).toBe("agent-1");
     expect(opts.limit).toBe(50);
     expect(opts.order).toBe("desc");
   });
@@ -216,8 +221,12 @@ describe("handleListMessages — API call arguments", () => {
       client,
     });
 
-    expect(convListSpy.mock.calls[0]?.[0]).toBe("agent-1");
-    const opts = convListSpy.mock.calls[0]?.[1] as { before?: string };
+    expect(convListSpy.mock.calls[0]?.[0]).toBe("default");
+    const opts = convListSpy.mock.calls[0]?.[1] as {
+      agent_id?: string;
+      before?: string;
+    };
+    expect(opts.agent_id).toBe("agent-1");
     expect(opts.before).toBe("msg-cursor-agents");
   });
 

src/tests/headless/list-messages-protocol.test.ts

@@ -192,28 +192,29 @@ describe("list_messages routing — resolveListMessagesRoute", () => {
 
   /**
    * Case C: no conversation_id in request, session is on the default conversation.
-   * Resolves to conversations API with agent ID as the conversation_id
-   * (server accepts agent-* IDs for agent-direct messaging).
+   * Keeps conversation_id="default" and passes agent_id separately.
    */
-  test("C — omitted conversation_id + session default → conversations API with session agentId", () => {
+  test("C — omitted conversation_id + session default → conversations API with default + session agentId", () => {
     const route = resolveListMessagesRoute(
       {}, // no conversation_id
       "default", // session is on default conversation
       SESSION_AGENT,
     );
     expect(route.kind).toBe("conversations");
-    expect(route.conversationId).toBe(SESSION_AGENT);
+    expect(route.conversationId).toBe("default");
+    expect(route.agentId).toBe(SESSION_AGENT);
   });
 
-  test("C — explicit agent_id in request + session default → uses request agentId", () => {
+  test("C — explicit agent_id in request + session default → uses request agentId query", () => {
     const route = resolveListMessagesRoute(
       { agent_id: "agent-override-id" },
       "default",
       SESSION_AGENT,
     );
     expect(route.kind).toBe("conversations");
+    expect(route.conversationId).toBe("default");
     // Request's agent_id takes priority over session agent when on default conv
-    expect(route.conversationId).toBe("agent-override-id");
+    expect(route.agentId).toBe("agent-override-id");
   });
 
   test("C — no conversation_id, no agent_id, session default → falls back to session agentId", () => {
@@ -223,7 +224,8 @@ describe("list_messages routing — resolveListMessagesRoute", () => {
       "agent-session-fallback",
     );
     expect(route.kind).toBe("conversations");
-    expect(route.conversationId).toBe("agent-session-fallback");
+    expect(route.conversationId).toBe("default");
+    expect(route.agentId).toBe("agent-session-fallback");
   });
 
   /**