fix(web): derive MCP URLs for any Supabase URL, not only *.supabase.co

packages/web/src/lib/mcp-url.spec.ts

@@ -5,11 +5,15 @@ import { resolveMcpUrls } from './mcp-url';
 // restore it around every case so the tests don't leak env state into each
 // other (or into the rest of the suite).
 const KEY = 'NEXT_PUBLIC_SUPABASE_URL';
+const LOCAL_FLAG = 'NEXT_PUBLIC_USE_LOCAL_SUPABASE';
 const original = process.env[KEY];
+const originalFlag = process.env[LOCAL_FLAG];
 
 afterEach(() => {
   if (original === undefined) delete process.env[KEY];
   else process.env[KEY] = original;
+  if (originalFlag === undefined) delete process.env[LOCAL_FLAG];
+  else process.env[LOCAL_FLAG] = originalFlag;
 });
 
 // The hardcoded fallback ref baked into mcp-url.ts, used when the env var is
@@ -42,10 +46,45 @@ describe('resolveMcpUrls', () => {
     expect(resolveMcpUrls().mcpUrl).toBe(FALLBACK);
   });
 
-  it('strips both the https:// prefix and the .supabase.co suffix to isolate the ref', () => {
-    // A bare ref (no scheme, no suffix) leaves nothing to strip, so it is used
-    // verbatim as the project ref — proving the derivation is a plain replace.
-    process.env[KEY] = 'myref';
-    expect(resolveMcpUrls().mcpUrl).toBe('https://myref.supabase.co/functions/v1/mcp');
+  it('ignores a trailing slash on a *.supabase.co URL', () => {
+    process.env[KEY] = 'https://abcdefghijklmnop.supabase.co/';
+    expect(resolveMcpUrls().mcpUrl).toBe('https://abcdefghijklmnop.supabase.co/functions/v1/mcp');
+  });
+
+  it('derives the MCP URL from a self-hosted custom domain', () => {
+    process.env[KEY] = 'https://db.example.com';
+    const { mcpUrl, webhookUrl } = resolveMcpUrls();
+    expect(mcpUrl).toBe('https://db.example.com/functions/v1/mcp');
+    expect(webhookUrl).toBe('https://db.example.com/functions/v1/mcp/webhooks/github');
+  });
+
+  it('ignores a trailing slash on a custom domain', () => {
+    process.env[KEY] = 'https://db.example.com/';
+    expect(resolveMcpUrls().mcpUrl).toBe('https://db.example.com/functions/v1/mcp');
+  });
+
+  it('keeps the scheme and port of a local http Supabase', () => {
+    process.env[KEY] = 'http://127.0.0.1:54321';
+    expect(resolveMcpUrls().mcpUrl).toBe('http://127.0.0.1:54321/functions/v1/mcp');
+  });
+
+  it('keeps a reverse-proxy base path, minus its trailing slash', () => {
+    process.env[KEY] = 'https://example.com/supabase/';
+    expect(resolveMcpUrls().mcpUrl).toBe('https://example.com/supabase/functions/v1/mcp');
+  });
+
+  it.each([
+    ['a bare word that is not a URL', 'myref'],
+    ['whitespace only', '   '],
+    ['a non-http scheme', 'ftp://db.example.com'],
+  ])('falls back to the hosted URL for %s', (_label, value) => {
+    process.env[KEY] = value;
+    expect(resolveMcpUrls().mcpUrl).toBe(FALLBACK);
+  });
+
+  it('follows the local stack when NEXT_PUBLIC_USE_LOCAL_SUPABASE is set, like every other client', () => {
+    process.env[KEY] = 'https://abcdefghijklmnop.supabase.co';
+    process.env[LOCAL_FLAG] = 'true';
+    expect(resolveMcpUrls().mcpUrl).toBe('http://127.0.0.1:54321/functions/v1/mcp');
   });
 });

packages/web/src/lib/mcp-url.ts

@@ -1,13 +1,33 @@
+import { supabaseUrl } from './supabase/config';
+
+/** The hosted LoreKit MCP endpoint, used when no usable Supabase URL is configured. */
+const HOSTED_MCP_URL = 'https://pqokxlhvnosogizsjztg.supabase.co/functions/v1/mcp';
+
 /**
- * Resolve the user's MCP + webhook URLs from the Supabase project ref.
- * Shared by the dashboard onboarding and the settings pages so the derivation
- * lives in exactly one place.
+ * Normalise a Supabase base URL (`https://<ref>.supabase.co`, a self-hosted
+ * custom domain, or a local `http://127.0.0.1:54321`) to `origin + path` with
+ * no trailing slash. Returns `null` for anything that is not an absolute
+ * http(s) URL, so the caller can fall back instead of emitting a broken URL.
+ */
+function supabaseBaseUrl(raw: string): string | null {
+  let url: URL;
+  try {
+    url = new URL(raw.trim());
+  } catch {
+    return null;
+  }
+  if (url.protocol !== 'https:' && url.protocol !== 'http:') return null;
+  return `${url.origin}${url.pathname.replace(/\/+$/, '')}`;
+}
+
+/**
+ * Resolve the user's MCP + webhook URLs from the dashboard's Supabase URL
+ * (`supabaseUrl()`, so `NEXT_PUBLIC_USE_LOCAL_SUPABASE` is honoured) — any
+ * Supabase base URL, not only `*.supabase.co`. Shared by the dashboard
+ * onboarding and the settings pages so the derivation lives in exactly one place.
  */
 export function resolveMcpUrls(): { mcpUrl: string; webhookUrl: string } {
-  const supabaseUrl = process.env['NEXT_PUBLIC_SUPABASE_URL'] ?? '';
-  const projectRef = supabaseUrl.replace('https://', '').replace('.supabase.co', '');
-  const mcpUrl = projectRef
-    ? `https://${projectRef}.supabase.co/functions/v1/mcp`
-    : 'https://pqokxlhvnosogizsjztg.supabase.co/functions/v1/mcp';
+  const base = supabaseBaseUrl(supabaseUrl());
+  const mcpUrl = base ? `${base}/functions/v1/mcp` : HOSTED_MCP_URL;
   return { mcpUrl, webhookUrl: `${mcpUrl}/webhooks/github` };
 }