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

ts/smartagent.classes.agent.ts

@@ -156,6 +156,7 @@ export async function runAgent(options: IAgentRunOptions): Promise<IAgentRunResu
   let validationRetries = 0;
   const toolCalls: IAgentToolCallRecord[] = [];
   const toolCallIndexes = new Map<string, number>();
+  const reasoningTextById = new Map<string, string>();
 
   const tools = options.tools ?? {};
   const cache = options.cache ?? 'auto';
@@ -227,8 +228,33 @@ export async function runAgent(options: IAgentRunOptions): Promise<IAgentRunResu
         },
 
         onChunk: ({ chunk }) => {
-          if (chunk.type === 'text-delta' && options.onToken) {
-            options.onToken((chunk as any).textDelta ?? (chunk as any).text ?? '');
+          const chunkType = String((chunk as any).type || '');
+          if (chunkType === 'text-delta' && options.onToken) {
+            options.onToken((chunk as any).delta ?? (chunk as any).textDelta ?? (chunk as any).text ?? '');
+            return;
+          }
+          if (chunkType === 'reasoning-start') {
+            const id = (chunk as any).id || 'reasoning';
+            reasoningTextById.set(id, '');
+            options.onReasoningStart?.(id, (chunk as any).providerMetadata);
+            return;
+          }
+          if (chunkType === 'reasoning-delta') {
+            const id = (chunk as any).id || 'reasoning';
+            const delta = (chunk as any).delta ?? (chunk as any).textDelta ?? (chunk as any).text ?? '';
+            if (!reasoningTextById.has(id)) {
+              reasoningTextById.set(id, '');
+              options.onReasoningStart?.(id, (chunk as any).providerMetadata);
+            }
+            reasoningTextById.set(id, (reasoningTextById.get(id) ?? '') + delta);
+            options.onReasoningDelta?.(id, delta, (chunk as any).providerMetadata);
+            return;
+          }
+          if (chunkType === 'reasoning-end') {
+            const id = (chunk as any).id || 'reasoning';
+            const text = reasoningTextById.get(id) ?? '';
+            reasoningTextById.delete(id);
+            options.onReasoningEnd?.(id, text, (chunk as any).providerMetadata);
           }
         },
 
@@ -286,6 +312,10 @@ export async function runAgent(options: IAgentRunOptions): Promise<IAgentRunResu
       const finishReason = await result.finishReason;
       const responseData = await result.response;
       const responseMessages = responseData.messages as plugins.ModelMessage[];
+      for (const [id, reasoningText] of reasoningTextById) {
+        options.onReasoningEnd?.(id, reasoningText);
+        reasoningTextById.delete(id);
+      }
 
       attempt = 0; // reset on success
 

ts/smartagent.interfaces.ts

@@ -45,6 +45,12 @@ export interface IAgentRunOptions {
   messages?: ModelMessage[];
   /** Called for each streamed text delta */
   onToken?: (delta: string) => void;
+  /** Called when the model starts a streamed reasoning summary */
+  onReasoningStart?: (id: string, providerMetadata?: unknown) => void;
+  /** Called for each streamed reasoning summary delta */
+  onReasoningDelta?: (id: string, delta: string, providerMetadata?: unknown) => void;
+  /** Called when a streamed reasoning summary completes */
+  onReasoningEnd?: (id: string, text: string, providerMetadata?: unknown) => void;
   /** Called when a tool call starts */
   onToolCall?: (toolName: string, input: unknown) => void;
   /** Called when a tool call completes */