diff --git a/packages/sdk/src/actions/index.ts b/packages/sdk/src/actions/index.ts
index e73947a4e..045254643 100644
--- a/packages/sdk/src/actions/index.ts
+++ b/packages/sdk/src/actions/index.ts
@@ -37,4 +37,5 @@ export {
   type StreamMessageEvent,
   type StreamToolEvent,
   extractTextFromEvent,
+  extractThinkingFromEvent,
 } from "./stream";
diff --git a/packages/sdk/src/actions/stream.ts b/packages/sdk/src/actions/stream.ts
index 513290400..032bb9628 100644
--- a/packages/sdk/src/actions/stream.ts
+++ b/packages/sdk/src/actions/stream.ts
@@ -12,7 +12,7 @@ export interface StreamMessageEvent {
   message: {
     id?: string;
     role: string;
-    content?: Array<{ type: string; text?: string }>;
+    content?: Array<{ type: string; text?: string; thinking?: string }>;
   };
   assistantMessageEvent?: unknown;
 }
@@ -47,3 +47,13 @@ export function extractTextFromEvent(event: StreamMessageEvent): string {
     .map((c) => c.text ?? "")
     .join("");
 }
+
+/** Extract thinking/reasoning content from an AgentMessage content array */
+export function extractThinkingFromEvent(event: StreamMessageEvent): string {
+  const content = event.message?.content;
+  if (!Array.isArray(content)) return "";
+  return content
+    .filter((c) => c.type === "thinking")
+    .map((c) => c.thinking ?? "")
+    .join("");
+}