From 060bf99e83154cafff2855d464fc0f422fa9fe3b Mon Sep 17 00:00:00 2001
From: Anthony Ettinger <anthony@profullstack.com>
Date: Wed, 11 Nov 2026 21:20:55 +0000
Subject: [PATCH] fix(mcp): never answer /api/mcp with the crawl gateway's 402
 (0.6.3)

Connector clients read a 402/403 with no WWW-Authenticate as 'needs
sign-in', find no OAuth metadata, and fail. claude.ai's custom-connector
submission hit 'Couldn't register with p0dcasters's sign-in service'.
/api/mcp is now an open path; its throttle budget is unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 package.json                |  2 +-
 src/lib/crawl-gateway.ts    |  9 ++++++++-
 test/crawl-gateway.test.mjs | 18 ++++++++++++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/package.json b/package.json
index bb55ef1..a6813a8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "p0dcasters",
-  "version": "0.6.2",
+  "version": "0.6.3",
   "private": true,
   "type": "module",
   "scripts": {
diff --git a/src/lib/crawl-gateway.ts b/src/lib/crawl-gateway.ts
index f4ffd8e..daf0ef7 100644
--- a/src/lib/crawl-gateway.ts
+++ b/src/lib/crawl-gateway.ts
@@ -73,7 +73,14 @@ export const gateway = createGateway({
   contact: "mailto:hello@p0dcasters.com",
   // A refused crawler may still read the map of the site, so the refusal is
   // legible to it rather than a wall. robots.txt and /crawl are always open.
-  openPaths: ["/llms.txt", "/skill.md"],
+  //
+  // /api/mcp is how an agent uses the directory, not how it copies it, so no
+  // user-agent list or spoofed-browser check ever answers it 402. Connector
+  // clients (claude.ai's custom-connector verifier among them) read any non-2xx
+  // without WWW-Authenticate as "needs sign-in", find no OAuth metadata and
+  // fail with "couldn't register with the sign-in service" (2026-11-11). The
+  // endpoint keeps its own per-caller budget in lib/throttle.ts.
+  openPaths: ["/llms.txt", "/skill.md", "/api/mcp"],
   training: TRAINING,
   retrieval: RETRIEVAL,
   denyCidrs: OVH_VPS_RANGES,
diff --git a/test/crawl-gateway.test.mjs b/test/crawl-gateway.test.mjs
index 58d435f..c5e995a 100644
--- a/test/crawl-gateway.test.mjs
+++ b/test/crawl-gateway.test.mjs
@@ -33,3 +33,21 @@ test('Lightpanda may still read robots.txt', async () => {
   const res = await gate(req('/robots.txt', { 'user-agent': 'Lightpanda/1.0' }));
   assert.notEqual(res?.status, 402);
 });
+
+test('the MCP endpoint is never sold, whatever the client calls itself', async () => {
+  for (const ua of ['anthropic-ai/1.0', 'ClaudeBot/1.0', CHROME, 'Lightpanda/1.0']) {
+    const res = await gate(
+      new Request('https://p0dcasters.com/api/mcp', {
+        method: 'POST',
+        headers: { 'x-forwarded-for': '37.231.157.22', 'user-agent': ua, 'content-type': 'application/json' },
+        body: '{}',
+      }),
+    );
+    assert.equal(res ?? undefined, undefined, ua);
+  }
+});
+
+test('OAuth discovery under /.well-known is never sold', async () => {
+  const res = await gate(req('/.well-known/oauth-protected-resource', { 'user-agent': 'anthropic-ai/1.0' }));
+  assert.notEqual(res?.status, 402);
+});