diff --git a/packages/sdk/src/client.ts b/packages/sdk/src/client.ts
index 5abdcc8be73..b4a012e30a4 100644
--- a/packages/sdk/src/client.ts
+++ b/packages/sdk/src/client.ts
@@ -695,7 +695,14 @@ export class Session {
   async send(input: string | Omit<SessionSendParams, "key">): Promise<Run> {
     const params: SessionSendParams =
       typeof input === "string" ? { key: this.key, message: input } : { ...input, key: this.key };
-    const raw = await this.client.request("sessions.send", params, { expectFinal: true });
+    const timeoutMs = normalizeTimeoutMs(params.timeoutMs);
+    if (timeoutMs !== undefined) {
+      params.timeoutMs = timeoutMs;
+    }
+    const raw = await this.client.request("sessions.send", params, {
+      expectFinal: true,
+      ...(timeoutMs !== undefined ? { timeoutMs: timeoutMs === 0 ? null : timeoutMs } : {}),
+    });
     const record = asRecord(raw);
     const runId = readOptionalString(record.runId);
     if (!runId) {
diff --git a/packages/sdk/src/index.test.ts b/packages/sdk/src/index.test.ts
index 876a1803c8e..d91a2420f15 100644
--- a/packages/sdk/src/index.test.ts
+++ b/packages/sdk/src/index.test.ts
@@ -1339,9 +1339,11 @@ describe("OpenClaw SDK", () => {
     const oc = new OpenClaw({ transport });
 
     const session = await oc.sessions.create({ key: "session-main" });
-    const run = await session.send({ message: "continue", thinking: "medium" });
+    const run = await session.send({ message: "continue", thinking: "medium", timeoutMs: 1_500 });
+    const noTimeoutRun = await session.send({ message: "continue without timeout", timeoutMs: 0 });
 
     expect(run.id).toBe("run_session");
+    expect(noTimeoutRun.id).toBe("run_session");
     expect(transport.calls).toEqual([
       {
         method: "sessions.create",
@@ -1350,8 +1352,13 @@ describe("OpenClaw SDK", () => {
       },
       {
         method: "sessions.send",
-        options: { expectFinal: true },
-        params: { key: "session-main", message: "continue", thinking: "medium" },
+        options: { expectFinal: true, timeoutMs: 1_500 },
+        params: { key: "session-main", message: "continue", thinking: "medium", timeoutMs: 1_500 },
+      },
+      {
+        method: "sessions.send",
+        options: { expectFinal: true, timeoutMs: null },
+        params: { key: "session-main", message: "continue without timeout", timeoutMs: 0 },
       },
     ]);
   });