fix(core): preserve first-turn display content

packages/cli/src/nonInteractiveCli.test.ts

@@ -265,6 +265,9 @@ describe('runNonInteractive', () => {
       [{ text: 'Test input' }],
       expect.any(AbortSignal),
       'prompt-id-1',
+      undefined,
+      false,
+      'Test input',
     );
     expect(getWrittenOutput()).toBe('Hello World\n');
     // Note: Telemetry shutdown is now handled in runExitCleanup() in cleanup.ts
@@ -429,6 +432,9 @@ describe('runNonInteractive', () => {
       [{ text: 'Tool response' }],
       expect.any(AbortSignal),
       'prompt-id-2',
+      undefined,
+      false,
+      undefined,
     );
     expect(getWrittenOutput()).toBe('Final answer\n');
   });
@@ -586,6 +592,9 @@ describe('runNonInteractive', () => {
       ],
       expect.any(AbortSignal),
       'prompt-id-3',
+      undefined,
+      false,
+      undefined,
     );
     expect(getWrittenOutput()).toBe('Sorry, let me try again.\n');
   });
@@ -725,6 +734,9 @@ describe('runNonInteractive', () => {
       processedParts,
       expect.any(AbortSignal),
       'prompt-id-7',
+      undefined,
+      false,
+      rawInput,
     );
 
     // 6. Assert the final output is correct
@@ -758,6 +770,9 @@ describe('runNonInteractive', () => {
       [{ text: 'Test input' }],
       expect.any(AbortSignal),
       'prompt-id-1',
+      undefined,
+      false,
+      'Test input',
     );
     expect(processStdoutSpy).toHaveBeenCalledWith(
       JSON.stringify(
@@ -961,6 +976,9 @@ describe('runNonInteractive', () => {
       [{ text: 'Empty response test' }],
       expect.any(AbortSignal),
       'prompt-id-empty',
+      undefined,
+      false,
+      'Empty response test',
     );
 
     // This should output JSON with empty response but include stats
@@ -1095,6 +1113,9 @@ describe('runNonInteractive', () => {
       [{ text: 'Prompt from command' }],
       expect.any(AbortSignal),
       'prompt-id-slash',
+      undefined,
+      false,
+      '/testcommand',
     );
 
     expect(getWrittenOutput()).toBe('Response from command\n');
@@ -1138,6 +1159,9 @@ describe('runNonInteractive', () => {
       [{ text: 'Slash command output' }],
       expect.any(AbortSignal),
       'prompt-id-slash',
+      undefined,
+      false,
+      '/help',
     );
     expect(getWrittenOutput()).toBe('Response to slash command\n');
     handleSlashCommandSpy.mockRestore();
@@ -1268,17 +1292,16 @@ describe('runNonInteractive', () => {
       (process.stdin as any).setRawMode = vi.fn();
     }
 
-    const stdinOnSpy = vi.spyOn(process.stdin, 'on').mockImplementation(
-      (
-        event: string | symbol,
-        listener: (...args: unknown[]) => void,
-      ) => {
-        if (event === 'keypress') {
-          listener('\u0003', { ctrl: true, name: 'c' });
-        }
-        return process.stdin;
-      },
-    );
+    const stdinOnSpy = vi
+      .spyOn(process.stdin, 'on')
+      .mockImplementation(
+        (event: string | symbol, listener: (...args: unknown[]) => void) => {
+          if (event === 'keypress') {
+            listener('\u0003', { ctrl: true, name: 'c' });
+          }
+          return process.stdin;
+        },
+      );
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     vi.spyOn(process.stdin as any, 'setRawMode').mockImplementation(() => true);
     vi.spyOn(process.stdin, 'resume').mockImplementation(() => process.stdin);
@@ -1377,6 +1400,9 @@ describe('runNonInteractive', () => {
       [{ text: '/unknowncommand' }],
       expect.any(AbortSignal),
       'prompt-id-unknown',
+      undefined,
+      false,
+      '/unknowncommand',
     );
 
     expect(getWrittenOutput()).toBe('Response to unknown\n');

packages/cli/src/nonInteractiveCli.ts

@@ -301,7 +301,10 @@ export async function runNonInteractive({
 
       // Start the agentic loop (runs in background)
       const { streamId } = await session.send({
-        message: geminiPartsToContentParts(query),
+        message: {
+          content: geminiPartsToContentParts(query),
+          displayContent: input,
+        },
       });
       if (streamId === null) {
         throw new Error(
@@ -465,18 +468,17 @@ export async function runNonInteractive({
               }
 
               if (event.data?.['errorType'] === ToolErrorType.NO_SPACE_LEFT) {
-                runTerminalExitHandler(() =>
-                  handleToolError(
-                    event.name,
-                    new Error(errorMsg),
-                    config,
-                    typeof event.data?.['errorType'] === 'string'
-                      ? event.data['errorType']
-                      : undefined,
-                    displayText,
-                  ),
+                terminalProcessExitHandled = true;
+                handleToolError(
+                  event.name,
+                  new Error(errorMsg),
+                  config,
+                  typeof event.data?.['errorType'] === 'string'
+                    ? event.data['errorType']
+                    : undefined,
+                  displayText,
                 );
-                break;
+                return;
               }
               handleToolError(
                 event.name,
@@ -528,7 +530,9 @@ export async function runNonInteractive({
                 typeof event.data?.['turnCount'] === 'number';
 
               if (isConfiguredTurnLimit) {
-                runTerminalExitHandler(() => handleMaxTurnsExceededError(config));
+                runTerminalExitHandler(() =>
+                  handleMaxTurnsExceededError(config),
+                );
               } else if (streamFormatter) {
                 streamFormatter.emitEvent({
                   type: JsonStreamEventType.ERROR,

packages/cli/src/utils/errors.ts

@@ -18,6 +18,7 @@ import {
   isFatalToolError,
   debugLogger,
   coreEvents,
+  getErrorType,
   getErrorMessage,
   getErrorType,
 } from '@google/gemini-cli-core';

packages/core/src/agent/agent-session.test.ts

@@ -7,7 +7,19 @@
 import { describe, expect, it } from 'vitest';
 import { AgentSession } from './agent-session.js';
 import { MockAgentProtocol } from './mock.js';
-import type { AgentEvent } from './types.js';
+import type { AgentEvent, AgentSend } from './types.js';
+
+function makeMessageSend(
+  text: string,
+  displayContent?: string,
+): Extract<AgentSend, { message: unknown }> {
+  return {
+    message: {
+      content: [{ type: 'text', text }],
+      ...(displayContent ? { displayContent } : {}),
+    },
+  };
+}
 
 describe('AgentSession', () => {
   it('should passthrough simple methods', async () => {
@@ -51,7 +63,7 @@ describe('AgentSession', () => {
 
     const events: AgentEvent[] = [];
     for await (const event of session.sendStream({
-      message: [{ type: 'text', text: 'hi' }],
+      ...makeMessageSend('hi'),
     })) {
       events.push(event);
     }
@@ -139,7 +151,7 @@ describe('AgentSession', () => {
 
     const events: AgentEvent[] = [];
     for await (const event of session.sendStream({
-      message: [{ type: 'text', text: 'hi' }],
+      ...makeMessageSend('hi'),
     })) {
       events.push(event);
     }
@@ -178,7 +190,7 @@ describe('AgentSession', () => {
 
       protocol.pushResponse([{ type: 'message' }]);
       const { streamId } = await session.send({
-        message: [{ type: 'text', text: 'request' }],
+        ...makeMessageSend('request'),
       });
       await new Promise((resolve) => setTimeout(resolve, 10));
 
@@ -242,7 +254,7 @@ describe('AgentSession', () => {
         },
       ]);
       await session.send({
-        message: [{ type: 'text', text: 'request' }],
+        ...makeMessageSend('request'),
       });
       await new Promise((resolve) => setTimeout(resolve, 10));
 
@@ -303,7 +315,7 @@ describe('AgentSession', () => {
         },
       ]);
       const { streamId: streamId1 } = await session.send({
-        message: [{ type: 'text', text: 'first request' }],
+        ...makeMessageSend('first request'),
       });
       await new Promise((resolve) => setTimeout(resolve, 10));
 
@@ -315,7 +327,7 @@ describe('AgentSession', () => {
         },
       ]);
       await session.send({
-        message: [{ type: 'text', text: 'second request' }],
+        ...makeMessageSend('second request'),
       });
       await new Promise((resolve) => setTimeout(resolve, 10));
 

packages/core/src/agent/event-translator.test.ts

@@ -679,6 +679,7 @@ describe('mapError', () => {
     expect(result.status).toBe('RESOURCE_EXHAUSTED');
     expect(result.message).toBe('Rate limit');
     expect(result.fatal).toBe(true);
+    expect(result._meta?.['status']).toBe(429);
     expect(result._meta?.['rawError']).toEqual({
       message: 'Rate limit',
       status: 429,

packages/core/src/agent/event-translator.ts

@@ -403,7 +403,7 @@ export function mapError(
   }
 
   if (isStructuredError(error)) {
-    const structuredMeta = { ...meta, rawError: error };
+    const structuredMeta = { ...meta, rawError: error, status: error.status };
     return {
       status: mapHttpToGrpcStatus(error.status),
       message: error.message,

packages/core/src/agent/legacy-agent-session.test.ts

@@ -10,7 +10,7 @@ import { LegacyAgentSession } from './legacy-agent-session.js';
 import type { LegacyAgentSessionDeps } from './legacy-agent-session.js';
 import { GeminiEventType } from '../core/turn.js';
 import type { ServerGeminiStreamEvent } from '../core/turn.js';
-import type { AgentEvent } from './types.js';
+import type { AgentEvent, AgentSend } from './types.js';
 import { ToolErrorType } from '../tools/tool-error.js';
 import type {
   CompletedToolCall,
@@ -72,6 +72,18 @@ function makeToolRequest(callId: string, name: string): ToolCallRequestInfo {
   };
 }
 
+function makeMessageSend(
+  text: string,
+  displayContent?: string,
+): Extract<AgentSend, { message: unknown }> {
+  return {
+    message: {
+      content: [{ type: 'text', text }],
+      ...(displayContent ? { displayContent } : {}),
+    },
+  };
+}
+
 function makeCompletedToolCall(
   callId: string,
   name: string,
@@ -140,9 +152,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      const result = await session.send({
-        message: [{ type: 'text', text: 'hi' }],
-      });
+      const result = await session.send(makeMessageSend('hi'));
 
       expect(result.streamId).toBe('test-stream');
     });
@@ -162,7 +172,10 @@ describe('LegacyAgentSession', () => {
 
       const session = new LegacyAgentSession(deps);
       const { streamId } = await session.send({
-        message: [{ type: 'text', text: 'hi' }],
+        message: {
+          content: [{ type: 'text', text: 'hi' }],
+          displayContent: 'raw input',
+        },
         _meta: { source: 'user-test' },
       });
 
@@ -170,12 +183,57 @@ describe('LegacyAgentSession', () => {
         (e): e is AgentEvent<'message'> =>
           e.type === 'message' && e.role === 'user' && e.streamId === streamId,
       );
-      expect(userMessage?.content).toEqual([{ type: 'text', text: 'hi' }]);
+      expect(userMessage?.content).toEqual([
+        { type: 'text', text: 'raw input' },
+      ]);
       expect(userMessage?._meta).toEqual({ source: 'user-test' });
+      await vi.advanceTimersByTimeAsync(0);
+      expect(sendMock).toHaveBeenCalledWith(
+        [{ text: 'hi' }],
+        expect.any(AbortSignal),
+        'test-prompt',
+        undefined,
+        false,
+        'raw input',
+      );
 
       await collectEvents(session, { streamId: streamId ?? undefined });
     });
 
+    it('accepts legacy message-array sends without displayContent', async () => {
+      const sendMock = deps.client.sendMessageStream as ReturnType<
+        typeof vi.fn
+      >;
+      sendMock.mockReturnValue(
+        makeStream([
+          {
+            type: GeminiEventType.Finished,
+            value: { reason: FinishReason.STOP, usageMetadata: undefined },
+          },
+        ]),
+      );
+
+      const session = new LegacyAgentSession(deps);
+      const { streamId } = await session.send({
+        message: [{ type: 'text', text: 'hi' }],
+      });
+
+      const userMessage = session.events.find(
+        (e): e is AgentEvent<'message'> =>
+          e.type === 'message' && e.role === 'user' && e.streamId === streamId,
+      );
+      expect(userMessage?.content).toEqual([{ type: 'text', text: 'hi' }]);
+      await vi.advanceTimersByTimeAsync(0);
+      expect(sendMock).toHaveBeenCalledWith(
+        [{ text: 'hi' }],
+        expect.any(AbortSignal),
+        'test-prompt',
+        undefined,
+        false,
+        undefined,
+      );
+    });
+
     it('returns streamId before emitting agent_start', async () => {
       const sendMock = deps.client.sendMessageStream as ReturnType<
         typeof vi.fn
@@ -195,9 +253,7 @@ describe('LegacyAgentSession', () => {
         liveEvents.push(event);
       });
 
-      const { streamId } = await session.send({
-        message: [{ type: 'text', text: 'hi' }],
-      });
+      const { streamId } = await session.send(makeMessageSend('hi'));
 
       expect(streamId).toBe('test-stream');
       expect(liveEvents.some((event) => event.type === 'agent_start')).toBe(
@@ -235,14 +291,12 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      const { streamId } = await session.send({
-        message: [{ type: 'text', text: 'first' }],
-      });
+      const { streamId } = await session.send(makeMessageSend('first'));
       await vi.advanceTimersByTimeAsync(0);
 
-      await expect(
-        session.send({ message: [{ type: 'text', text: 'second' }] }),
-      ).rejects.toThrow('cannot be called while a stream is active');
+      await expect(session.send(makeMessageSend('second'))).rejects.toThrow(
+        'cannot be called while a stream is active',
+      );
 
       resolveHang?.();
       await collectEvents(session, { streamId: streamId ?? undefined });
@@ -273,16 +327,12 @@ describe('LegacyAgentSession', () => {
         );
 
       const session = new LegacyAgentSession(deps);
-      const first = await session.send({
-        message: [{ type: 'text', text: 'first' }],
-      });
+      const first = await session.send(makeMessageSend('first'));
       const firstEvents = await collectEvents(session, {
         streamId: first.streamId ?? undefined,
       });
 
-      const second = await session.send({
-        message: [{ type: 'text', text: 'second' }],
-      });
+      const second = await session.send(makeMessageSend('second'));
       const secondEvents = await collectEvents(session, {
         streamId: second.streamId ?? undefined,
       });
@@ -330,7 +380,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const types = events.map((e) => e.type);
@@ -387,7 +437,7 @@ describe('LegacyAgentSession', () => {
       ]);
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'read a file' }] });
+      await session.send(makeMessageSend('read a file'));
       const events = await collectEvents(session);
 
       const types = events.map((e) => e.type);
@@ -455,9 +505,7 @@ describe('LegacyAgentSession', () => {
       scheduleMock.mockResolvedValueOnce([errorToolCall]);
 
       const session = new LegacyAgentSession(deps);
-      await session.send({
-        message: [{ type: 'text', text: 'write file' }],
-      });
+      await session.send(makeMessageSend('write file'));
       const events = await collectEvents(session);
 
       const toolResp = events.find(
@@ -506,9 +554,7 @@ describe('LegacyAgentSession', () => {
       scheduleMock.mockResolvedValueOnce([stopToolCall]);
 
       const session = new LegacyAgentSession(deps);
-      await session.send({
-        message: [{ type: 'text', text: 'do something' }],
-      });
+      await session.send(makeMessageSend('do something'));
       const events = await collectEvents(session);
 
       const streamEnd = events.find(
@@ -552,9 +598,7 @@ describe('LegacyAgentSession', () => {
       scheduleMock.mockResolvedValueOnce([fatalToolCall]);
 
       const session = new LegacyAgentSession(deps);
-      await session.send({
-        message: [{ type: 'text', text: 'write file' }],
-      });
+      await session.send(makeMessageSend('write file'));
       const events = await collectEvents(session);
 
       const toolResp = events.find(
@@ -592,7 +636,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const streamEnd = events.find(
@@ -621,7 +665,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const blocked = events.find(
@@ -663,7 +707,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const err = events.find(
@@ -690,7 +734,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const warning = events.find(
@@ -738,7 +782,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const streamEnd = events.find(
@@ -762,7 +806,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const errorEvents = events.filter(
@@ -799,9 +843,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      const { streamId } = await session.send({
-        message: [{ type: 'text', text: 'hi' }],
-      });
+      const { streamId } = await session.send(makeMessageSend('hi'));
       await vi.advanceTimersByTimeAsync(0);
 
       await session.abort();
@@ -847,7 +889,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
 
       // Give the loop time to start processing
       await new Promise((r) => setTimeout(r, 50));
@@ -891,9 +933,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      const { streamId } = await session.send({
-        message: [{ type: 'text', text: 'hi' }],
-      });
+      const { streamId } = await session.send(makeMessageSend('hi'));
 
       await new Promise((resolve) => setTimeout(resolve, 25));
       await session.abort();
@@ -935,7 +975,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       await collectEvents(session);
 
       expect(session.events.length).toBeGreaterThan(0);
@@ -964,9 +1004,7 @@ describe('LegacyAgentSession', () => {
         liveEvents.push(event);
       });
 
-      const { streamId } = await session.send({
-        message: [{ type: 'text', text: 'hi' }],
-      });
+      const { streamId } = await session.send(makeMessageSend('hi'));
       await collectEvents(session, { streamId: streamId ?? undefined });
       unsubscribe();
 
@@ -1002,9 +1040,7 @@ describe('LegacyAgentSession', () => {
         );
 
       const session = new LegacyAgentSession(deps);
-      const first = await session.send({
-        message: [{ type: 'text', text: 'first request' }],
-      });
+      const first = await session.send(makeMessageSend('first request'));
       await collectEvents(session, { streamId: first.streamId ?? undefined });
 
       const liveEvents: AgentEvent[] = [];
@@ -1012,9 +1048,7 @@ describe('LegacyAgentSession', () => {
         liveEvents.push(event);
       });
 
-      const second = await session.send({
-        message: [{ type: 'text', text: 'second request' }],
-      });
+      const second = await session.send(makeMessageSend('second request'));
       await collectEvents(session, { streamId: second.streamId ?? undefined });
       unsubscribe();
 
@@ -1058,14 +1092,10 @@ describe('LegacyAgentSession', () => {
         );
 
       const session = new LegacyAgentSession(deps);
-      const first = await session.send({
-        message: [{ type: 'text', text: 'first request' }],
-      });
+      const first = await session.send(makeMessageSend('first request'));
       await collectEvents(session, { streamId: first.streamId ?? undefined });
 
-      const second = await session.send({
-        message: [{ type: 'text', text: 'second request' }],
-      });
+      const second = await session.send(makeMessageSend('second request'));
       await collectEvents(session, { streamId: second.streamId ?? undefined });
 
       const firstStreamEvents = await collectEvents(session, {
@@ -1120,14 +1150,10 @@ describe('LegacyAgentSession', () => {
         );
 
       const session = new LegacyAgentSession(deps);
-      const first = await session.send({
-        message: [{ type: 'text', text: 'first request' }],
-      });
+      const first = await session.send(makeMessageSend('first request'));
       await collectEvents(session, { streamId: first.streamId ?? undefined });
 
-      await session.send({
-        message: [{ type: 'text', text: 'second request' }],
-      });
+      await session.send(makeMessageSend('second request'));
       await collectEvents(session);
 
       const firstAgentMessage = session.events.find(
@@ -1175,7 +1201,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       expect(events.length).toBeGreaterThan(0);
@@ -1196,7 +1222,7 @@ describe('LegacyAgentSession', () => {
       );
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       expect(events[events.length - 1]?.type).toBe('agent_end');
@@ -1244,7 +1270,7 @@ describe('LegacyAgentSession', () => {
       ]);
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'do it' }] });
+      await session.send(makeMessageSend('do it'));
       const events = await collectEvents(session);
 
       // Only one agent_end at the very end
@@ -1291,7 +1317,7 @@ describe('LegacyAgentSession', () => {
       ]);
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'go' }] });
+      await session.send(makeMessageSend('go'));
       const events = await collectEvents(session);
 
       // Should have at least one usage event from the intermediate Finished
@@ -1314,7 +1340,7 @@ describe('LegacyAgentSession', () => {
       });
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const err = events.find(
@@ -1342,7 +1368,7 @@ describe('LegacyAgentSession', () => {
       });
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const err = events.find(
@@ -1365,7 +1391,7 @@ describe('LegacyAgentSession', () => {
       });
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const err = events.find(
@@ -1385,7 +1411,7 @@ describe('LegacyAgentSession', () => {
       });
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const err = events.find(
@@ -1405,7 +1431,7 @@ describe('LegacyAgentSession', () => {
       });
 
       const session = new LegacyAgentSession(deps);
-      await session.send({ message: [{ type: 'text', text: 'hi' }] });
+      await session.send(makeMessageSend('hi'));
       const events = await collectEvents(session);
 
       const err = events.find(

packages/core/src/agent/legacy-agent-session.ts

@@ -93,6 +93,9 @@ class LegacyAgentProtocol implements AgentProtocol {
         'LegacyAgentSession.send() only supports message sends for the moment.',
       );
     }
+    const normalizedMessage = Array.isArray(message)
+      ? { content: message, displayContent: undefined }
+      : message;
 
     if (this._activeStreamId) {
       // TODO: Interactive may eventually allow selected in-stream sends such as
@@ -105,12 +108,16 @@ class LegacyAgentProtocol implements AgentProtocol {
 
     this._beginNewStream();
     const streamId = this._translationState.streamId;
-    const parts = contentPartsToGeminiParts(message);
-    const userMessage = this._makeUserMessageEvent(message, payload._meta);
+    const parts = contentPartsToGeminiParts(normalizedMessage.content);
+    const userMessage = this._makeUserMessageEvent(
+      normalizedMessage.content,
+      normalizedMessage.displayContent,
+      payload._meta,
+    );
 
     this._emit([userMessage]);
 
-    this._scheduleRunLoop(parts);
+    this._scheduleRunLoop(parts, normalizedMessage.displayContent);
 
     return { streamId };
   }
@@ -119,18 +126,24 @@ class LegacyAgentProtocol implements AgentProtocol {
     this._abortController.abort();
   }
 
-  private _scheduleRunLoop(initialParts: Part[]): void {
+  private _scheduleRunLoop(
+    initialParts: Part[],
+    displayContent?: string,
+  ): void {
     // Use a macrotask so send() resolves with the streamId before agent_start
     // is emitted and consumers can attach to the stream without racing startup.
     setTimeout(() => {
-      void this._runLoopInBackground(initialParts);
+      void this._runLoopInBackground(initialParts, displayContent);
     }, 0);
   }
 
-  private async _runLoopInBackground(initialParts: Part[]): Promise<void> {
+  private async _runLoopInBackground(
+    initialParts: Part[],
+    displayContent?: string,
+  ): Promise<void> {
     this._ensureAgentStart();
     try {
-      await this._runLoop(initialParts);
+      await this._runLoop(initialParts, displayContent);
     } catch (err: unknown) {
       if (this._abortController.signal.aborted || isAbortLikeError(err)) {
         this._ensureAgentEnd('aborted');
@@ -141,8 +154,12 @@ class LegacyAgentProtocol implements AgentProtocol {
     }
   }
 
-  private async _runLoop(initialParts: Part[]): Promise<void> {
+  private async _runLoop(
+    initialParts: Part[],
+    initialDisplayContent?: string,
+  ): Promise<void> {
     let currentParts: Part[] = initialParts;
+    let currentDisplayContent = initialDisplayContent;
     let turnCount = 0;
     const maxTurns = this._config.getMaxSessionTurns();
 
@@ -162,7 +179,11 @@ class LegacyAgentProtocol implements AgentProtocol {
         currentParts,
         this._abortController.signal,
         this._promptId,
+        undefined,
+        false,
+        currentDisplayContent,
       );
+      currentDisplayContent = undefined;
 
       for await (const event of responseStream) {
         if (this._abortController.signal.aborted) {
@@ -383,13 +404,17 @@ class LegacyAgentProtocol implements AgentProtocol {
 
   private _makeUserMessageEvent(
     content: ContentPart[],
+    displayContent?: string,
     meta?: Record<string, unknown>,
   ): AgentEvent<'message'> {
+    const eventContent: ContentPart[] = displayContent
+      ? [{ type: 'text', text: displayContent }]
+      : content;
     const event = {
       ...this._nextEventFields(),
       type: 'message',
       role: 'user',
-      content,
+      content: eventContent,
       ...(meta ? { _meta: meta } : {}),
     } satisfies AgentEvent<'message'>;
     return event;

packages/core/src/agent/mock.test.ts

@@ -34,7 +34,7 @@ describe('MockAgentProtocol', () => {
     const streamPromise = waitForStreamEnd(session);
 
     const { streamId } = await session.send({
-      message: [{ type: 'text', text: 'hi' }],
+      message: { content: [{ type: 'text', text: 'hi' }] },
     });
     expect(streamId).toBeDefined();
 

packages/core/src/agent/mock.ts

@@ -10,6 +10,7 @@ import type {
   AgentEventData,
   AgentProtocol,
   AgentSend,
+  ContentPart,
   Unsubscribe,
 } from './types.js';
 
@@ -133,11 +134,17 @@ export class MockAgentProtocol implements AgentProtocol {
 
     // 1. User/Update event (BEFORE agent_start)
     if ('message' in payload && payload.message) {
+      const message = Array.isArray(payload.message)
+        ? { content: payload.message, displayContent: undefined }
+        : payload.message;
+      const userContent: ContentPart[] = message.displayContent
+        ? [{ type: 'text', text: message.displayContent }]
+        : message.content;
       eventsToEmit.push(
         normalize({
           type: 'message',
           role: 'user',
-          content: payload.message,
+          content: userContent,
           _meta: payload._meta,
         }),
       );

packages/core/src/agent/types.ts

@@ -46,7 +46,12 @@ type RequireExactlyOne<T> = {
 }[keyof T];
 
 interface AgentSendPayloads {
-  message: ContentPart[];
+  message:
+    | ContentPart[]
+    | {
+        content: ContentPart[];
+        displayContent?: string;
+      };
   elicitations: ElicitationResponse[];
   update: { title?: string; model?: string; config?: Record<string, unknown> };
   action: { type: string; data: unknown };