ChatGPT Apps Authentication: Auth0 OAuth Tutorial (2026)

Implement authentication for ChatGPT Apps SDK using the MCP OAuth standard and Auth0. In this tutorial, you’ll see the end-to-end OAuth flow in ChatGPT, then we’ll break down the MCP auth spec and walk through the exact code setup. In the previous video we covered state + _meta["openai/subject"]. In this one, we go from “anonymous identity” to real user authentication with OAuth. To learn about building MCP Servers Live, Join my free course on Maven with this link: https://maven.com/p/89571e/build-and-deploy-your-first-mcp-server-live?utm_medium=ll_share_link&utm_source=instructor CHAPTERS 0:00 Introduction 1:16 Demo: App Authentication Flow (ChatGPT → Auth0 → Back) 3:12 Understanding OAuth for MCP Servers (MCP Auth Standard) 6:45 Auth0 Setup (App + Callback URLs) 7:59 Code Walkthrough (Auth0BackedOAuthProvider + server config) 13:10 Wrap Up + Next Steps WHAT YOU’LL LEARN How ChatGPT connects to an authenticated MCP server (OAuth 2.1 + PKCE + DCR) How the MCP server publishes protected-resource metadata and OAuth discovery How we use Auth0 to handle login, then mint tokens for tool calls How to scope data per-user in your ChatGPT App backend RESOURCES GitHub Repo (Task Manager App): https://github.com/hollaugo/tutorials/tree/main/task-manager-app OpenAI Apps SDK Auth Guide: https://developers.openai.com/apps-sdk/build/auth MCP Authorization Spec: https://modelcontextprotocol.io/specification/2025-06-18/basic/authorization FAQ How do I add authentication to a ChatGPT App? Use OAuth on your MCP server + an identity provider like Auth0, as described in the Apps SDK auth guide. Do I need to build an authorization server myself? No—Auth0 handles the user login and token validation primitives, and you implement the MCP OAuth-required endpoints. Why does ChatGPT require PKCE + dynamic client registration? It’s part of the MCP OAuth expectations for secure, per-connector client identities. If you have questions about connector setup, callback URLs, or debugging the OAuth flow—drop them in the comments.