feat(indiekit): client metadata endpoint

packages/indiekit/lib/controllers/client.js

@@ -0,0 +1,13 @@
+export const get = async (request, response) => {
+  const { name: client_name, url: client_uri } = request.app.locals.application;
+  const { href: client_id } = new URL("id", client_uri);
+  const { href: logo_uri } = new URL("assets/app-icon-512-any.png", client_uri);
+
+  response.set("Cache-Control", "public, max-age=604800"); // 7 days
+  return response.type("application/json").json({
+    client_id,
+    client_name,
+    client_uri,
+    logo_uri,
+  });
+};

packages/indiekit/lib/indieauth.js

@@ -79,14 +79,16 @@ export const IndieAuth = class {
     return async (request, response) => {
       try {
         const { application } = request.app.locals;
-        this.clientId = getCanonicalUrl(application.url);
+        const applicationUrl = getCanonicalUrl(application.url);
+        const { href: clientId } = new URL("id", applicationUrl);
+        const { href: callbackUrl } = new URL("session/auth", applicationUrl);
 
-        const callbackUrl = `${application.url}/session/auth`;
         const { redirect } = request.query;
         this.redirectUri = redirect
           ? `${callbackUrl}?redirect=${redirect}`
           : `${callbackUrl}`;
 
+        this.clientId = clientId;
         const state = generateState(this.clientId, this.iv);
         const authUrl = await this.getAuthUrl(
           application.authorizationEndpoint,

packages/indiekit/lib/routes.js

@@ -3,6 +3,7 @@ import express from "express";
 import { assetsPath } from "@indiekit/frontend";
 import rateLimit from "express-rate-limit";
 import * as assetsController from "./controllers/assets.js";
+import * as clientController from "./controllers/client.js";
 import * as feedController from "./controllers/feed.js";
 import * as homepageController from "./controllers/homepage.js";
 import * as manifestController from "./controllers/manifest.js";
@@ -70,6 +71,9 @@ export const routes = (indiekitConfig) => {
   // Web App Manifest
   router.get("/app.webmanifest", manifestController.get);
 
+  // Client metadata
+  router.get("/id", clientController.get);
+
   // Session
   router.get("/session/login", limit, sessionController.login);
   router.post("/session/login", limit, indieauth.login());

packages/indiekit/test/integration/200-client.js

@@ -0,0 +1,24 @@
+import { strict as assert } from "node:assert";
+import { after, describe, it } from "node:test";
+import supertest from "supertest";
+import { testServer } from "@indiekit-test/server";
+
+const server = await testServer();
+const request = supertest.agent(server);
+
+describe("indiekit GET /id", () => {
+  it("Returns client metadata", async () => {
+    const result = await request.get("/id");
+
+    assert.equal(result.status, 200);
+    assert.equal(result.type, "application/json");
+    assert.equal(result.body.client_id.includes("/id"), true);
+    assert.equal(result.body.client_name, "Test configuration");
+    assert.ok(result.body.client_uri);
+    assert.equal(result.body.logo_uri.includes("app-icon-512-any.png"), true);
+  });
+
+  after(() => {
+    server.close(() => process.exit(0));
+  });
+});