Connect a remote AI with OAuth
Use this path when the AI runs in a browser or hosted service and asks for a remote MCP server URL.
https://krexel.com/api/mcp
That is the only value you copy. You do not need to create an API key, register an OAuth client, choose a callback URL, or handle a client secret.
What happens after you add the URL
- The AI client contacts Krexel's MCP endpoint.
- Krexel returns its protected-resource and OAuth discovery information.
- The client registers itself automatically and starts authorization with PKCE S256.
- Krexel opens in your browser. Sign in and approve access.
- The client exchanges the authorization code for a scoped access token.
- The client can call Krexel tools on your behalf and refresh its token when required.
The token is bound to the Krexel MCP resource and the krexel.mcp scope.
ChatGPT
- Open ChatGPT Settings.
- Under Security and login, enable Developer mode.
- Open Settings → Plugins, select the plus button, and add a custom MCP server.
- Enter
https://krexel.com/api/mcp. - Sign in to Krexel and approve access.
- Start a new chat, enable Krexel from the tools menu, and ask: “List my Krexel sites.”
Developer mode availability can depend on your ChatGPT plan and workspace policy.
Claude.ai and other remote MCP clients
Choose Add custom connector or the equivalent remote MCP option, then paste
https://krexel.com/api/mcp. If the client supports standard MCP OAuth, it
will discover registration and sign-in automatically.
Do not paste an /oauth/authorize URL. Do not paste a krx_... API key into
an OAuth client form.
Troubleshooting
- Sign-in never opens — remove the connection, add the exact MCP URL again, and refresh the client's connector metadata.
- The client reports
401 Unauthorized— reconnect so it can repeat OAuth. Do not replace the OAuth token with an API key. - The consent page loops back to sign-in — sign in to Krexel in the same browser window, then retry the connection.
- Tools do not appear after a deployment — refresh the connection metadata and start a new conversation.
- Your workspace has no Developer mode or custom connector option — that is a client-plan or administrator policy. Use the local MCP setup from a supported coding assistant.
Building your own OAuth client
Only use Advanced OAuth clients if you are building your own application rather than connecting a standard MCP host.
Your application must:
- use authorization code with PKCE S256;
- discover endpoints from
https://krexel.com/.well-known/oauth-authorization-server; - send the
resourcevalue returned by protected-resource metadata through both authorization and token exchange; - request the
krexel.mcpscope; - register exact HTTPS callback URLs;
- keep confidential client secrets out of browser and mobile code.
Standard MCP hosts should use dynamic client registration instead.