diff --git a/src/config/types.hooks.ts b/src/config/types.hooks.ts
index 7ca74605a..d748cc453 100644
--- a/src/config/types.hooks.ts
+++ b/src/config/types.hooks.ts
@@ -36,6 +36,7 @@ export type HookMappingConfig = {
   thinking?: string;
   timeoutSeconds?: number;
   transform?: HookMappingTransform;
+    agentId?: string;
 };
 
 export type HooksGmailTailscaleMode = "off" | "serve" | "funnel";
diff --git a/src/gateway/hooks-mapping.ts b/src/gateway/hooks-mapping.ts
index 2ebf9b136..df9a37037 100644
--- a/src/gateway/hooks-mapping.ts
+++ b/src/gateway/hooks-mapping.ts
@@ -22,6 +22,7 @@ export type HookMappingResolved = {
   thinking?: string;
   timeoutSeconds?: number;
   transform?: HookMappingTransformResolved;
+    agentId?: string;
 };
 
 export type HookMappingTransformResolved = {
@@ -55,6 +56,7 @@ export type HookAction =
       model?: string;
       thinking?: string;
       timeoutSeconds?: number;
+        agentId?: string;
     };
 
 export type HookMappingResult =
diff --git a/src/gateway/hooks.ts b/src/gateway/hooks.ts
index 1fc6d52f4..00027ec33 100644
--- a/src/gateway/hooks.ts
+++ b/src/gateway/hooks.ts
@@ -137,6 +137,7 @@ export type HookAgentPayload = {
   model?: string;
   thinking?: string;
   timeoutSeconds?: number;
+    agentId?: string;
 };
 
 const listHookChannelValues = () => ["last", ...listChannelPlugins().map((plugin) => plugin.id)];
@@ -195,7 +196,9 @@ export function normalizeAgentPayload(
   const timeoutSeconds =
     typeof timeoutRaw === "number" && Number.isFinite(timeoutRaw) && timeoutRaw > 0
       ? Math.floor(timeoutRaw)
-      : undefined;
+      : un
+      const agentIdRaw = payload.agentId;
+  const agentId = typeof agentIdRaw === "string" && agentIdRaw.trim() ? agentIdRaw.trim() : undefined;defined;
   return {
     ok: true,
     value: {
@@ -209,6 +212,7 @@ export function normalizeAgentPayload(
       model,
       thinking,
       timeoutSeconds,
+                agentId,
     },
   };
 }
diff --git a/test/hooks.agentId.test.ts b/test/hooks.agentId.test.ts
new file mode 100644
index 000000000..7684a9b08
--- /dev/null
+++ b/test/hooks.agentId.test.ts
@@ -0,0 +1,68 @@
+import { describe, it, expect } from "vitest";
+import { normalizeAgentPayload } from "../src/gateway/hooks.js";
+
+describe("normalizeAgentPayload agentId support", () => {
+  it("should accept agentId as a string", () => {
+    const payload = {
+      message: "test message",
+      channel: "last",
+      agentId: "agent-123",
+    };
+    const result = normalizeAgentPayload(payload);
+    expect(result.ok).toBe(true);
+    if (result.ok) {
+      expect(result.value.agentId).toBe("agent-123");
+    }
+  });
+
+  it("should trim agentId whitespace", () => {
+    const payload = {
+      message: "test message",
+      channel: "last",
+      agentId: "  agent-456  ",
+    };
+    const result = normalizeAgentPayload(payload);
+    expect(result.ok).toBe(true);
+    if (result.ok) {
+      expect(result.value.agentId).toBe("agent-456");
+    }
+  });
+
+  it("should handle missing agentId as undefined", () => {
+    const payload = {
+      message: "test message",
+      channel: "last",
+    };
+    const result = normalizeAgentPayload(payload);
+    expect(result.ok).toBe(true);
+    if (result.ok) {
+      expect(result.value.agentId).toBeUndefined();
+    }
+  });
+
+  it("should ignore empty agentId strings", () => {
+    const payload = {
+      message: "test message",
+      channel: "last",
+      agentId: "  ",
+    };
+    const result = normalizeAgentPayload(payload);
+    expect(result.ok).toBe(true);
+    if (result.ok) {
+      expect(result.value.agentId).toBeUndefined();
+    }
+  });
+
+  it("should handle non-string agentId as undefined", () => {
+    const payload = {
+      message: "test message",
+      channel: "last",
+      agentId: 123,
+    } as any;
+    const result = normalizeAgentPayload(payload);
+    expect(result.ok).toBe(true);
+    if (result.ok) {
+      expect(result.value.agentId).toBeUndefined();
+    }
+  });
+});