fix: make hosted MCP connector compatible with Claude and Grok

apps/web/__tests__/unit/mcp-auth.test.ts

@@ -97,9 +97,10 @@ describe("MCP OAuth authorization", () => {
 			true,
 		);
 		expect(isMcpRedirectUri("http://127.0.0.1:49152/callback")).toBe(true);
+		expect(isMcpRedirectUri("http://localhost:49152/callback")).toBe(true);
 		for (const uri of [
 			"http://chatgpt.com/connector/callback",
-			"http://localhost:49152/callback",
+			"http://localhost.evil.example:49152/callback",
 			"http://127.0.0.1/callback",
 			"https://chatgpt.com/connector/callback#fragment",
 			"https://user:password@chatgpt.com/callback",

apps/web/__tests__/unit/mcp-server.test.ts

@@ -83,30 +83,31 @@ describe("hosted MCP transport", () => {
 	});
 
 	it("preserves browser preflight and OAuth challenge headers", async () => {
-		const origin = "https://chatgpt.com";
-		const preflight = await OPTIONS(
-			new Request("https://cap.so/api/mcp", {
-				method: "OPTIONS",
-				headers: { Origin: origin },
-			}),
-		);
-		expect(preflight.status).toBe(204);
-		expect(preflight.headers.get("access-control-allow-origin")).toBe(origin);
-		expect(preflight.headers.get("cache-control")).toBe("no-store");
-		const unauthorized = await POST(
-			new Request("https://cap.so/api/mcp", {
-				method: "POST",
-				headers: { Origin: origin, "Content-Type": "application/json" },
-				body: "{}",
-			}),
-		);
-		expect(unauthorized.status).toBe(401);
-		expect(unauthorized.headers.get("access-control-allow-origin")).toBe(
-			origin,
-		);
-		expect(unauthorized.headers.get("www-authenticate")).toContain(
-			"resource_metadata",
-		);
+		for (const origin of ["https://chatgpt.com", "https://grok.com"]) {
+			const preflight = await OPTIONS(
+				new Request("https://cap.so/api/mcp", {
+					method: "OPTIONS",
+					headers: { Origin: origin },
+				}),
+			);
+			expect(preflight.status).toBe(204);
+			expect(preflight.headers.get("access-control-allow-origin")).toBe(origin);
+			expect(preflight.headers.get("cache-control")).toBe("no-store");
+			const unauthorized = await POST(
+				new Request("https://cap.so/api/mcp", {
+					method: "POST",
+					headers: { Origin: origin, "Content-Type": "application/json" },
+					body: "{}",
+				}),
+			);
+			expect(unauthorized.status).toBe(401);
+			expect(unauthorized.headers.get("access-control-allow-origin")).toBe(
+				origin,
+			);
+			expect(unauthorized.headers.get("www-authenticate")).toContain(
+				"resource_metadata",
+			);
+		}
 	});
 
 	it("keeps host, origin, media type, and body limits ahead of MCP dispatch", async () => {
@@ -150,6 +151,32 @@ describe("hosted MCP transport", () => {
 		expect(listBody).toContain("caps_list");
 		expect(listBody).toContain("caps_get");
 		expect(listBody).toContain("caps_context");
+		expect(listBody).toContain('"openWorldHint":false');
+		const data = listBody.split("\n").find((line) => line.startsWith("data: "));
+		expect(data).toBeDefined();
+		const tools = JSON.parse(data?.slice(6) ?? "").result.tools;
+		expect(tools).toEqual(
+			expect.arrayContaining([
+				expect.objectContaining({
+					name: "caps_list",
+					annotations: expect.objectContaining({
+						title: "List Cap recordings",
+					}),
+				}),
+				expect.objectContaining({
+					name: "caps_get",
+					annotations: expect.objectContaining({
+						title: "Get a Cap recording",
+					}),
+				}),
+				expect.objectContaining({
+					name: "caps_context",
+					annotations: expect.objectContaining({
+						title: "Read a Cap recording",
+					}),
+				}),
+			]),
+		);
 		expect(listBody).not.toContain("caps_delete");
 		const called = await POST(
 			request({

apps/web/app/api/mcp/route.ts

@@ -24,6 +24,7 @@ const allowedOrigins = () =>
 		"https://chatgpt.com",
 		"https://claude.ai",
 		"https://muse.ai",
+		"https://grok.com",
 	]);
 
 const corsHeaders = (request: Request) => {

apps/web/lib/mcp-auth.ts

@@ -37,7 +37,9 @@ export const isMcpRedirectUri = (value: string) => {
 		const url = new URL(value);
 		const loopback =
 			url.protocol === "http:" &&
-			(url.hostname === "127.0.0.1" || url.hostname === "[::1]") &&
+			(url.hostname === "localhost" ||
+				url.hostname === "127.0.0.1" ||
+				url.hostname === "[::1]") &&
 			url.port.length > 0;
 		return (
 			(url.protocol === "https:" || loopback) &&

apps/web/lib/mcp-server.ts

@@ -17,6 +17,7 @@ const readOnly = {
 	readOnlyHint: true,
 	destructiveHint: false,
 	idempotentHint: true,
+	openWorldHint: false,
 };
 
 const result = (value: Record<string, unknown>) => ({
@@ -54,7 +55,7 @@ export const createCapMcpServer = (userId: User.UserId) => {
 				},
 				additionalProperties: false,
 			}),
-			annotations: readOnly,
+			annotations: { ...readOnly, title: "List Cap recordings" },
 		},
 		async (input) => {
 			try {
@@ -77,7 +78,7 @@ export const createCapMcpServer = (userId: User.UserId) => {
 				required: ["id"],
 				additionalProperties: false,
 			}),
-			annotations: readOnly,
+			annotations: { ...readOnly, title: "Get a Cap recording" },
 		},
 		async ({ id }) => {
 			try {
@@ -105,7 +106,7 @@ export const createCapMcpServer = (userId: User.UserId) => {
 				required: ["id"],
 				additionalProperties: false,
 			}),
-			annotations: readOnly,
+			annotations: { ...readOnly, title: "Read a Cap recording" },
 			_meta: { ui: { resourceUri: cardUri }, "openai/outputTemplate": cardUri },
 		},
 		async ({ id, query }) => {