refactor(routing): centralize inbound last-route policy

src/routing/resolve-route.test.ts

@@ -2,7 +2,11 @@ import { describe, expect, test, vi } from "vitest";
 import type { ChatType } from "../channels/chat-type.js";
 import type { OpenClawConfig } from "../config/config.js";
 import * as routingBindings from "./bindings.js";
-import { resolveAgentRoute } from "./resolve-route.js";
+import {
+  deriveLastRoutePolicy,
+  resolveAgentRoute,
+  resolveInboundLastRouteSessionKey,
+} from "./resolve-route.js";
 
 describe("resolveAgentRoute", () => {
   const resolveDiscordGuildRoute = (cfg: OpenClawConfig) =>
@@ -25,6 +29,7 @@ describe("resolveAgentRoute", () => {
     expect(route.agentId).toBe("main");
     expect(route.accountId).toBe("default");
     expect(route.sessionKey).toBe("agent:main:main");
+    expect(route.lastRoutePolicy).toBe("main");
     expect(route.matchedBy).toBe("default");
   });
 
@@ -47,9 +52,47 @@ describe("resolveAgentRoute", () => {
         peer: { kind: "direct", id: "+15551234567" },
       });
       expect(route.sessionKey).toBe(testCase.expected);
+      expect(route.lastRoutePolicy).toBe("session");
     }
   });
 
+  test("resolveInboundLastRouteSessionKey follows route policy", () => {
+    expect(
+      resolveInboundLastRouteSessionKey({
+        route: {
+          mainSessionKey: "agent:main:main",
+          lastRoutePolicy: "main",
+        },
+        sessionKey: "agent:main:discord:direct:user-1",
+      }),
+    ).toBe("agent:main:main");
+
+    expect(
+      resolveInboundLastRouteSessionKey({
+        route: {
+          mainSessionKey: "agent:main:main",
+          lastRoutePolicy: "session",
+        },
+        sessionKey: "agent:main:telegram:atlas:direct:123",
+      }),
+    ).toBe("agent:main:telegram:atlas:direct:123");
+  });
+
+  test("deriveLastRoutePolicy collapses only main-session routes", () => {
+    expect(
+      deriveLastRoutePolicy({
+        sessionKey: "agent:main:main",
+        mainSessionKey: "agent:main:main",
+      }),
+    ).toBe("main");
+    expect(
+      deriveLastRoutePolicy({
+        sessionKey: "agent:main:telegram:direct:123",
+        mainSessionKey: "agent:main:main",
+      }),
+    ).toBe("session");
+  });
+
   test("identityLinks applies to direct-message scopes", () => {
     const cases = [
       {

src/routing/resolve-route.ts

@@ -44,6 +44,8 @@ export type ResolvedAgentRoute = {
   sessionKey: string;
   /** Convenience alias for direct-chat collapse. */
   mainSessionKey: string;
+  /** Which session should receive inbound last-route updates. */
+  lastRoutePolicy: "main" | "session";
   /** Match description for debugging/logging. */
   matchedBy:
     | "binding.peer"
@@ -58,6 +60,20 @@ export type ResolvedAgentRoute = {
 
 export { DEFAULT_ACCOUNT_ID, DEFAULT_AGENT_ID } from "./session-key.js";
 
+export function deriveLastRoutePolicy(params: {
+  sessionKey: string;
+  mainSessionKey: string;
+}): ResolvedAgentRoute["lastRoutePolicy"] {
+  return params.sessionKey === params.mainSessionKey ? "main" : "session";
+}
+
+export function resolveInboundLastRouteSessionKey(params: {
+  route: Pick<ResolvedAgentRoute, "lastRoutePolicy" | "mainSessionKey">;
+  sessionKey: string;
+}): string {
+  return params.route.lastRoutePolicy === "main" ? params.route.mainSessionKey : params.sessionKey;
+}
+
 function normalizeToken(value: string | undefined | null): string {
   return (value ?? "").trim().toLowerCase();
 }
@@ -662,6 +678,7 @@ export function resolveAgentRoute(input: ResolveAgentRouteInput): ResolvedAgentR
       accountId,
       sessionKey,
       mainSessionKey,
+      lastRoutePolicy: deriveLastRoutePolicy({ sessionKey, mainSessionKey }),
       matchedBy,
     };
     if (routeCache && routeCacheKey) {