feat(agent): add streamed reasoning summary callbacks to runAgent

test/test.ts

@@ -33,6 +33,25 @@ const createTextStreamResult = (text: string) => ({
   ] as any[]),
 });
 
+const createReasoningStreamResult = (reasoning: string, text: string) => ({
+  stream: convertArrayToReadableStream([
+    { type: 'stream-start', warnings: [] },
+    { type: 'response-metadata', id: 'response-1', timestamp: new Date(0), modelId: 'mock-model' },
+    { type: 'reasoning-start', id: 'reasoning-1' },
+    { type: 'reasoning-delta', id: 'reasoning-1', delta: reasoning.slice(0, 7) },
+    { type: 'reasoning-delta', id: 'reasoning-1', delta: reasoning.slice(7) },
+    { type: 'reasoning-end', id: 'reasoning-1' },
+    { type: 'text-start', id: 'text-1' },
+    { type: 'text-delta', id: 'text-1', delta: text },
+    { type: 'text-end', id: 'text-1' },
+    {
+      type: 'finish',
+      finishReason: { unified: 'stop', raw: 'stop' },
+      usage: createUsage(2, 2),
+    },
+  ] as any[]),
+});
+
 const createToolCallStreamResult = (toolName: string, input: unknown) => ({
   stream: convertArrayToReadableStream([
     { type: 'stream-start', warnings: [] },
@@ -131,6 +150,32 @@ tap.test('runAgent should add OpenAI cache defaults when sessionId is provided',
   expect(openaiOptions.reasoningEffort).toEqual('high');
 });
 
+tap.test('runAgent should stream reasoning summary callbacks', async () => {
+  const reasoningEvents: string[] = [];
+  const tokenDeltas: string[] = [];
+  const model = new MockLanguageModelV3({
+    doStream: async () => createReasoningStreamResult('thinking through it', 'done') as any,
+  });
+
+  const result = await smartagent.runAgent({
+    model,
+    prompt: 'hello',
+    onToken: (delta) => tokenDeltas.push(delta),
+    onReasoningStart: (id) => reasoningEvents.push('start:' + id),
+    onReasoningDelta: (id, delta) => reasoningEvents.push('delta:' + id + ':' + delta),
+    onReasoningEnd: (id, text) => reasoningEvents.push('end:' + id + ':' + text),
+  });
+
+  expect(result.text).toEqual('done');
+  expect(tokenDeltas.join('')).toEqual('done');
+  expect(reasoningEvents).toEqual([
+    'start:reasoning-1',
+    'delta:reasoning-1:thinkin',
+    'delta:reasoning-1:g through it',
+    'end:reasoning-1:thinking through it',
+  ]);
+});
+
 tap.test('runAgent should mark Anthropic prompt cache breakpoints by default', async () => {
   const model = new MockLanguageModelV3({
     provider: 'anthropic',