Use Keycloak OAuth for a2amcp login

tests/config.test.ts

@@ -5,6 +5,7 @@ import path from "node:path";
 import { promises as fs } from "node:fs";
 
 import { addAgent, loadConfig, removeAgent } from "../src/config.js";
+import { loadCredentials, saveCredentials } from "../src/credentials.js";
 
 let originalHome: string | undefined;
 let tmpHome: string;
@@ -44,3 +45,31 @@ test("removeAgent reports hit/miss", async () => {
   const cfg = await loadConfig();
   assert.equal(cfg.agents.length, 0);
 });
+
+test("credentials preserve Keycloak token metadata", async () => {
+  await saveCredentials({
+    apiUrl: "https://api.example.test",
+    token: "access-token",
+    refreshToken: "refresh-token",
+    expiresAt: 12345,
+    email: "dev@example.test",
+    userId: 7,
+    bucket: "user-7-files",
+    issuer: "https://auth.example.test/realms/a2a",
+    clientId: "a2acloud-cli",
+    scope: "openid email mcp:invoke",
+  });
+
+  assert.deepEqual(await loadCredentials(), {
+    apiUrl: "https://api.example.test",
+    token: "access-token",
+    refreshToken: "refresh-token",
+    expiresAt: 12345,
+    email: "dev@example.test",
+    userId: 7,
+    bucket: "user-7-files",
+    issuer: "https://auth.example.test/realms/a2a",
+    clientId: "a2acloud-cli",
+    scope: "openid email mcp:invoke",
+  });
+});

tests/oauth.test.ts

@@ -0,0 +1,95 @@
+import { test, beforeEach, afterEach } from "node:test";
+import assert from "node:assert/strict";
+import os from "node:os";
+import path from "node:path";
+import { promises as fs } from "node:fs";
+
+import { loadCredentials, saveCredentials } from "../src/credentials.js";
+import {
+  buildAuthorizationUrl,
+  createPkcePair,
+  refreshCredentialsIfNeeded,
+} from "../src/oauth.js";
+
+let originalHome: string | undefined;
+let tmpHome: string;
+const originalFetch = globalThis.fetch;
+
+beforeEach(async () => {
+  originalHome = process.env.HOME;
+  tmpHome = await fs.mkdtemp(path.join(os.tmpdir(), "a2a-mcp-oauth-"));
+  process.env.HOME = tmpHome;
+  globalThis.fetch = originalFetch;
+});
+
+afterEach(async () => {
+  if (originalHome !== undefined) process.env.HOME = originalHome;
+  else delete process.env.HOME;
+  globalThis.fetch = originalFetch;
+  await fs.rm(tmpHome, { recursive: true, force: true });
+});
+
+test("PKCE authorization URL requests Keycloak code flow", () => {
+  const pkce = createPkcePair();
+  assert.ok(pkce.verifier.length > 40);
+  assert.ok(pkce.challenge.length > 40);
+
+  const url = new URL(
+    buildAuthorizationUrl({
+      authorizationEndpoint: "https://auth.example.test/auth",
+      clientId: "a2acloud-cli",
+      redirectUri: "http://127.0.0.1:41873/callback",
+      scope: "openid email mcp:invoke",
+      state: "state-123",
+      codeChallenge: pkce.challenge,
+    }),
+  );
+
+  assert.equal(url.searchParams.get("client_id"), "a2acloud-cli");
+  assert.equal(url.searchParams.get("response_type"), "code");
+  assert.equal(url.searchParams.get("code_challenge_method"), "S256");
+  assert.equal(url.searchParams.get("scope"), "openid email mcp:invoke");
+});
+
+test("refreshCredentialsIfNeeded refreshes expired Keycloak access token", async () => {
+  const calls: Array<{ url: string; body?: string }> = [];
+  globalThis.fetch = (async (input: RequestInfo | URL, init?: RequestInit) => {
+    const url = String(input);
+    calls.push({ url, body: init?.body?.toString() });
+    if (url.endsWith("/.well-known/openid-configuration")) {
+      return new Response(
+        JSON.stringify({
+          authorization_endpoint: "https://auth.example.test/auth",
+          token_endpoint: "https://auth.example.test/token",
+        }),
+        { status: 200, headers: { "content-type": "application/json" } },
+      );
+    }
+    return new Response(
+      JSON.stringify({
+        access_token: "fresh-token",
+        refresh_token: "fresh-refresh",
+        expires_in: 3600,
+        scope: "openid email mcp:invoke",
+      }),
+      { status: 200, headers: { "content-type": "application/json" } },
+    );
+  }) as typeof fetch;
+
+  await saveCredentials({
+    apiUrl: "https://api.example.test",
+    token: "old-token",
+    refreshToken: "refresh-token",
+    expiresAt: 1,
+    email: "dev@example.test",
+    issuer: "https://auth.example.test",
+    clientId: "a2acloud-cli",
+  });
+
+  const refreshed = await refreshCredentialsIfNeeded((await loadCredentials())!);
+
+  assert.equal(refreshed.token, "fresh-token");
+  assert.equal(refreshed.refreshToken, "fresh-refresh");
+  assert.equal((await loadCredentials())!.token, "fresh-token");
+  assert.ok(calls.some((call) => call.body?.includes("grant_type=refresh_token")));
+});