Restore hosted Subrouter CLI configuration

web/app/api/cli/config/route.ts

@@ -1,3 +1,8 @@
+import {
+  defaultHostedSubrouterURL,
+  hostedSubrouterBaseURL,
+} from "@/services/subrouter/constants";
+
 export const runtime = "nodejs";
 export const dynamic = "force-dynamic";
 
@@ -10,6 +15,15 @@ export function GET(request: Request): Response {
   if (!projectId || !publishableClientKey) {
     return unavailableResponse();
   }
+  let subrouterUrl: string;
+  try {
+    subrouterUrl = hostedSubrouterBaseURL(
+      process.env.SUBROUTER_HOSTED_URL?.trim() ||
+        defaultHostedSubrouterURL(),
+    );
+  } catch {
+    return unavailableResponse();
+  }
 
   return Response.json(
     {
@@ -29,6 +43,15 @@ export function GET(request: Request): Response {
         accountsUrl: new URL("/api/coderouter/accounts", request.url).toString(),
         openaiBaseUrl: new URL("/v1", request.url).toString(),
       },
+      // Keep the hosted Subrouter fields for released sr clients while cmux
+      // migrates its CodeRouter data plane to Vercel.
+      subrouter: {
+        url: subrouterUrl,
+        exchangeUrl: new URL(
+          "/api/subrouter/tenant-exchange",
+          request.url,
+        ).toString(),
+      },
     },
     {
       headers: {

web/tests/cli-config-route.test.ts

@@ -5,12 +5,14 @@ type CliConfigEnvKey =
   | "NEXT_PUBLIC_STACK_API_URL"
   | "NEXT_PUBLIC_STACK_PROJECT_ID"
   | "NEXT_PUBLIC_STACK_PUBLISHABLE_CLIENT_KEY"
+  | "SUBROUTER_HOSTED_URL"
   | "VERCEL_ENV";
 
 const testEnvironment = {
   NEXT_PUBLIC_STACK_API_URL: "https://stack.example.test/api/v1",
   NEXT_PUBLIC_STACK_PROJECT_ID: "test-stack-project-id",
   NEXT_PUBLIC_STACK_PUBLISHABLE_CLIENT_KEY: "test-stack-publishable-key",
+  SUBROUTER_HOSTED_URL: "https://subrouter.example.test",
   VERCEL_ENV: "preview",
 } satisfies Record<CliConfigEnvKey, string>;
 
@@ -46,7 +48,7 @@ async function withCliConfigEnvironment(
 }
 
 describe("CLI config route", () => {
-  test("publishes native Stack Auth and the Vercel CodeRouter data plane", async () => {
+  test("publishes CodeRouter and the hosted Subrouter POST contract", async () => {
     await withCliConfigEnvironment(testEnvironment, async () => {
       const response = GET(new Request("https://cmux.com/api/cli/config"));
       expect(response.status).toBe(200);
@@ -65,6 +67,10 @@ describe("CLI config route", () => {
           accountsUrl: "https://cmux.com/api/coderouter/accounts",
           openaiBaseUrl: "https://cmux.com/v1",
         },
+        subrouter: {
+          url: testEnvironment.SUBROUTER_HOSTED_URL,
+          exchangeUrl: "https://cmux.com/api/subrouter/tenant-exchange",
+        },
       });
     });
   });