fix(mcp): authenticate lazily instead of polling idle accounts

modules/linear-mcp/README.md

@@ -69,12 +69,17 @@ the Coder linking page is retained; query parameters and raw subprocess errors
 are never printed. If the credential context is unavailable and Coder cannot
 supply a URL, the reply gives the CLI command to retrieve it.
 
-The adapter checks authentication every 30 seconds. After linking Linear in
-Coder, it sends `notifications/tools/list_changed` when tools become available.
-Clients that honor that notification update automatically; clients that cache
-tool lists may require a reconnect. Unlinking hides tools again. Rejected
-upstream credentials also hide tools while keeping the local MCP healthy.
-Network outages return a sanitized MCP error and can recover on later requests.
+Authentication is lazy: initialization and idle time do not retrieve credentials
+or contact the provider. Listing or calling tools retrieves a current Coder token
+for each upstream HTTP request, without a separate preflight check. There is no
+background authentication timer or credential cache.
+
+After linking in Coder, refresh the client's tool list or reconnect if it caches
+an empty list. Account changes are discovered on the next request, rather than
+while idle; unlinking or HTTP 401/403 hides tools and keeps the local MCP healthy.
+Tool-list-change notifications are sent when a request connects or disconnects
+the upstream client. Upstream outages return sanitized errors and recover on
+later requests.
 
 ## Installation and credentials
 

modules/linear-mcp/scripts/linear-mcp.mjs

@@ -56,7 +56,6 @@ export function createAdapter({ providerId = 'linear', accessMode = 'read-only',
   let connecting;
   let initialized = false;
   let closed = false;
-  let poll;
   let shutdownPromise;
   let reportedAuthUrl;
   const notify = () => {
@@ -86,9 +85,7 @@ export function createAdapter({ providerId = 'linear', accessMode = 'read-only',
   };
   const ensureClient = async () => {
     if (closed) throw new Error('Adapter closed');
-    // Check even when a session exists: account unlinking must hide tools.
-    await getToken();
-    if (closed) throw new Error('Adapter closed');
+    // Authentication is checked by authenticatedFetch for each upstream request.
     if (client) return client;
     if (!connecting) connecting = (async () => {
       const candidate = new Client({ name: 'coder-linear-mcp', version: '1.0.0' });
@@ -142,26 +139,18 @@ export function createAdapter({ providerId = 'linear', accessMode = 'read-only',
       };
     }
   });
-  // Clients can discover newly linked accounts without restarting. Also
-  // detect account removal while idle; revoked tokens are caught by fetch.
-  const checkAuth = async () => {
-    try { await ensureClient(); } catch (error) { reportAuth(error); await disconnect(); }
-  };
+  // Stay idle until the client lists or calls tools. Coder may validate tokens
+  // against the provider, so even an idle authentication poll can consume quota.
   server.oninitialized = () => {
     initialized = true;
-    poll = setInterval(() => { checkAuth(); }, 30000);
-    poll.unref();
-    // Defer until the initial stdio handshake has completed.
-    setImmediate(() => { checkAuth(); });
   };
   const close = () => shutdownPromise ??= (async () => {
     closed = true;
-    clearInterval(poll);
     await disconnect();
     await connecting?.catch(() => {});
     await server.close();
   })();
-  return { server, checkAuth, close };
+  return { server, close };
 }
 
 async function main() {

modules/linear-mcp/tests/adapter.test.mjs

@@ -46,6 +46,31 @@ async function connect(t, options) {
   return { adapter, client };
 }
 
+test('initialization and idle time do not acquire credentials or contact the provider', async t => {
+  t.mock.timers.enable({ apis: ['setInterval'] });
+  let credentials = 0;
+  const remote = fakeLinear();
+  const { client } = await connect(t, {
+    getToken: async () => { credentials++; return 'fake-token'; },
+    fetchImpl: remote.fetchImpl,
+  });
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(credentials, 0);
+  assert.equal(remote.requests.length, 0);
+  t.mock.timers.tick(120000);
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(credentials, 0);
+  assert.equal(remote.requests.length, 0);
+
+  await client.listTools();
+  const used = credentials;
+  assert.ok(used > 0);
+  t.mock.timers.tick(120000);
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(credentials, used);
+  assert.equal(remote.requests.length, used);
+});
+
 test('unlinked accounts initialize successfully and expose zero tools without network calls', async t => {
   const { client } = await connect(t, {
     getToken: async () => { throw new AuthUnavailable(); },
@@ -61,19 +86,18 @@ test('unlinked accounts initialize successfully and expose zero tools without ne
 test('linking and unlinking update tools on the same MCP connection', async t => {
   let linked = false;
   const remote = fakeLinear();
-  const { adapter, client } = await connect(t, {
+  const { client } = await connect(t, {
     getToken: async () => { if (!linked) throw new AuthUnavailable(); return 'fake-token'; },
     fetchImpl: remote.fetchImpl,
   });
   assert.deepEqual((await client.listTools()).tools, []);
   let changes = 0;
   client.setNotificationHandler(ToolListChangedNotificationSchema, () => { changes++; });
   linked = true;
-  await adapter.checkAuth();
   assert.equal((await client.listTools()).tools[0].name, 'list_issues');
   assert.equal((await client.callTool({ name: 'list_issues', arguments: {} })).content[0].text, 'Example issue');
   linked = false;
-  await adapter.checkAuth();
+  assert.equal((await client.callTool({ name: 'list_issues', arguments: {} })).isError, true);
   assert.deepEqual((await client.listTools()).tools, []);
   await client.ping();
   assert.ok(changes >= 2);
@@ -90,6 +114,7 @@ test('each upstream request retrieves a fresh Coder token, including long sessio
   const tokens = remote.requests.map(request => request.token);
   assert.ok(tokens.length >= 3);
   assert.equal(new Set(tokens).size, tokens.length);
+  assert.equal(credentials, remote.requests.length, 'no redundant token preflight checks');
 });
 
 test('rejected OAuth credentials leave a healthy empty MCP without browser authentication', async t => {
@@ -158,7 +183,7 @@ test('invalid access modes cannot select an arbitrary endpoint', () => {
 test('unlinked tool replies include Coder linking URL and diagnostics are emitted once', async t => {
   const url = 'https://coder.example.test/external-auth/linear';
   const messages = [];
-  const { adapter, client } = await connect(t, {
+  const { client } = await connect(t, {
     getToken: async () => { throw new AuthUnavailable(url); },
     log: message => messages.push(message),
     fetchImpl: async () => assert.fail('must not contact Linear'),
@@ -167,7 +192,7 @@ test('unlinked tool replies include Coder linking URL and diagnostics are emitte
   const result = await client.callTool({ name: 'list_issues', arguments: {} });
   assert.equal(result.isError, true);
   assert.ok(result.content[0].text.includes(url));
-  await adapter.checkAuth();
+  await client.listTools();
   await client.ping();
   assert.deepEqual(messages, [`Linear MCP: link your account at ${url}`]);
 });

modules/notion-mcp/README.md

@@ -95,10 +95,17 @@ Coder supplies a linking URL, the adapter includes it in the reply and prints
 it once on stderr, stripping query parameters and raw subprocess diagnostics.
 Otherwise the reply gives the CLI command to obtain the link.
 
-The adapter checks authentication every 30 seconds and sends tool-list-change
-notifications after linking/unlinking. Clients that cache tools may need to
-reconnect. HTTP 401/403 hides tools without launching a separate browser OAuth
-flow; upstream outages produce sanitized errors and recover on later calls.
+Authentication is lazy: initialization and idle time do not retrieve credentials
+or contact the provider. Listing or calling tools retrieves a current Coder token
+for each upstream HTTP request, without a separate preflight check. There is no
+background authentication timer or credential cache.
+
+After linking in Coder, refresh the client's tool list or reconnect if it caches
+an empty list. Account changes are discovered on the next request, rather than
+while idle; unlinking or HTTP 401/403 hides tools and keeps the local MCP healthy.
+Tool-list-change notifications are sent when a request connects or disconnects
+the upstream client. Upstream outages return sanitized errors and recover on
+later requests.
 
 Every upstream request fetches a current token with
 `coder external-auth access-token <external_auth_id>`. Tokens remain in memory,

modules/notion-mcp/scripts/notion-mcp.mjs

@@ -87,7 +87,6 @@ export function createAdapter({ providerId = 'notion', accessMode = 'read-only',
   let connecting;
   let initialized = false;
   let closed = false;
-  let poll;
   let shutdownPromise;
   let reportedAuthUrl;
   const notify = () => {
@@ -117,9 +116,7 @@ export function createAdapter({ providerId = 'notion', accessMode = 'read-only',
   };
   const ensureClient = async () => {
     if (closed) throw new Error('Adapter closed');
-    // Check even when a session exists: account unlinking must hide tools.
-    await getToken();
-    if (closed) throw new Error('Adapter closed');
+    // Authentication is checked by authenticatedFetch for each upstream request.
     if (client) return client;
     if (!connecting) connecting = (async () => {
       const candidate = new Client({ name: 'coder-notion-mcp', version: '1.0.0' });
@@ -195,26 +192,18 @@ export function createAdapter({ providerId = 'notion', accessMode = 'read-only',
       };
     }
   });
-  // Clients can discover newly linked accounts without restarting. Also
-  // detect account removal while idle; revoked tokens are caught by fetch.
-  const checkAuth = async () => {
-    try { await ensureClient(); } catch (error) { reportAuth(error); await disconnect(); }
-  };
+  // Stay idle until the client lists or calls tools. Coder may validate tokens
+  // against the provider, so even an idle authentication poll can consume quota.
   server.oninitialized = () => {
     initialized = true;
-    poll = setInterval(() => { checkAuth(); }, 30000);
-    poll.unref();
-    // Defer until the initial stdio handshake has completed.
-    setImmediate(() => { checkAuth(); });
   };
   const close = () => shutdownPromise ??= (async () => {
     closed = true;
-    clearInterval(poll);
     await disconnect();
     await connecting?.catch(() => {});
     await server.close();
   })();
-  return { server, checkAuth, close };
+  return { server, close };
 }
 
 async function main() {

modules/notion-mcp/tests/adapter.test.mjs

@@ -49,6 +49,31 @@ async function connect(t, options) {
   return { adapter, client };
 }
 
+test('initialization and idle time do not acquire credentials or contact the provider', async t => {
+  t.mock.timers.enable({ apis: ['setInterval'] });
+  let credentials = 0;
+  const remote = fakeNotion();
+  const { client } = await connect(t, {
+    getToken: async () => { credentials++; return 'fake-token'; },
+    fetchImpl: remote.fetchImpl,
+  });
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(credentials, 0);
+  assert.equal(remote.requests.length, 0);
+  t.mock.timers.tick(120000);
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(credentials, 0);
+  assert.equal(remote.requests.length, 0);
+
+  await client.listTools();
+  const used = credentials;
+  assert.ok(used > 0);
+  t.mock.timers.tick(120000);
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(credentials, used);
+  assert.equal(remote.requests.length, used);
+});
+
 test('unlinked accounts initialize successfully and expose zero tools without network calls', async t => {
   const { client } = await connect(t, {
     getToken: async () => { throw new AuthUnavailable(); },
@@ -64,19 +89,18 @@ test('unlinked accounts initialize successfully and expose zero tools without ne
 test('linking and unlinking update tools on the same MCP connection', async t => {
   let linked = false;
   const remote = fakeNotion();
-  const { adapter, client } = await connect(t, {
+  const { client } = await connect(t, {
     getToken: async () => { if (!linked) throw new AuthUnavailable(); return 'fake-token'; },
     fetchImpl: remote.fetchImpl,
   });
   assert.deepEqual((await client.listTools()).tools, []);
   let changes = 0;
   client.setNotificationHandler(ToolListChangedNotificationSchema, () => { changes++; });
   linked = true;
-  await adapter.checkAuth();
   assert.equal((await client.listTools()).tools[0].name, 'notion-fetch');
   assert.equal((await client.callTool({ name: 'notion-fetch', arguments: {} })).content[0].text, 'Example page');
   linked = false;
-  await adapter.checkAuth();
+  assert.equal((await client.callTool({ name: 'notion-search', arguments: {} })).isError, true);
   assert.deepEqual((await client.listTools()).tools, []);
   await client.ping();
   assert.ok(changes >= 2);
@@ -93,6 +117,7 @@ test('each upstream request retrieves a fresh Coder token, including long sessio
   const tokens = remote.requests.map(request => request.token);
   assert.ok(tokens.length >= 3);
   assert.equal(new Set(tokens).size, tokens.length);
+  assert.equal(credentials, remote.requests.length, 'no redundant token preflight checks');
 });
 
 test('rejected OAuth credentials leave a healthy empty MCP without browser authentication', async t => {
@@ -161,7 +186,7 @@ test('invalid access modes cannot select an arbitrary endpoint', () => {
 test('unlinked tool replies include Coder linking URL and diagnostics are emitted once', async t => {
   const url = 'https://coder.example.test/external-auth/notion';
   const messages = [];
-  const { adapter, client } = await connect(t, {
+  const { client } = await connect(t, {
     getToken: async () => { throw new AuthUnavailable(url); },
     log: message => messages.push(message),
     fetchImpl: async () => assert.fail('must not contact Notion'),
@@ -170,7 +195,7 @@ test('unlinked tool replies include Coder linking URL and diagnostics are emitte
   const result = await client.callTool({ name: 'notion-fetch', arguments: {} });
   assert.equal(result.isError, true);
   assert.ok(result.content[0].text.includes(url));
-  await adapter.checkAuth();
+  await client.listTools();
   await client.ping();
   assert.deepEqual(messages, [`Notion MCP: link your account at ${url}`]);
 });

modules/slack-mcp/README.md

@@ -79,10 +79,17 @@ read-tool error replies and printed once to stderr. Only the linking-page URL
 is retained; query parameters and raw subprocess diagnostics are not relayed.
 If no URL is available, the reply gives the CLI command to obtain one.
 
-The adapter polls authentication every 30 seconds and notifies clients when
-linking/unlinking changes tool availability. Clients that cache tools may need
-a reconnect. Rejected credentials hide tools while keeping MCP healthy;
-upstream outages produce sanitized MCP errors and can recover on later calls.
+Authentication is lazy: initialization and idle time do not retrieve credentials
+or contact the provider. Listing or calling tools retrieves a current Coder token
+for each upstream HTTP request, without a separate preflight check. There is no
+background authentication timer or credential cache.
+
+After linking in Coder, refresh the client's tool list or reconnect if it caches
+an empty list. Account changes are discovered on the next request, rather than
+while idle; unlinking or HTTP 401/403 hides tools and keeps the local MCP healthy.
+Tool-list-change notifications are sent when a request connects or disconnects
+the upstream client. Upstream outages return sanitized errors and recover on
+later requests.
 
 Each upstream request obtains a current token using
 `coder external-auth access-token <external_auth_id>`. Coder manages refresh.

modules/slack-mcp/scripts/slack-mcp.mjs

@@ -67,7 +67,6 @@ export function createAdapter({ providerId = 'slack', accessMode = 'read-only',
   let connecting;
   let initialized = false;
   let closed = false;
-  let poll;
   let shutdownPromise;
   let reportedAuthUrl;
   const notify = () => {
@@ -97,9 +96,7 @@ export function createAdapter({ providerId = 'slack', accessMode = 'read-only',
   };
   const ensureClient = async () => {
     if (closed) throw new Error('Adapter closed');
-    // Check even when a session exists: account unlinking must hide tools.
-    await getToken();
-    if (closed) throw new Error('Adapter closed');
+    // Authentication is checked by authenticatedFetch for each upstream request.
     if (client) return client;
     if (!connecting) connecting = (async () => {
       const candidate = new Client({ name: 'coder-slack-mcp', version: '1.0.0' });
@@ -172,26 +169,18 @@ export function createAdapter({ providerId = 'slack', accessMode = 'read-only',
       };
     }
   });
-  // Clients can discover newly linked accounts without restarting. Also
-  // detect account removal while idle; revoked tokens are caught by fetch.
-  const checkAuth = async () => {
-    try { await ensureClient(); } catch (error) { reportAuth(error); await disconnect(); }
-  };
+  // Stay idle until the client lists or calls tools. Coder may validate tokens
+  // against the provider, so even an idle authentication poll can consume quota.
   server.oninitialized = () => {
     initialized = true;
-    poll = setInterval(() => { checkAuth(); }, 30000);
-    poll.unref();
-    // Defer until the initial stdio handshake has completed.
-    setImmediate(() => { checkAuth(); });
   };
   const close = () => shutdownPromise ??= (async () => {
     closed = true;
-    clearInterval(poll);
     await disconnect();
     await connecting?.catch(() => {});
     await server.close();
   })();
-  return { server, checkAuth, close };
+  return { server, close };
 }
 
 async function main() {