Connect to ChatGPT

ChatGPT supports MCP servers via its remote connector system. Use the same endpoint as Claude.

:::info Requirements

• ChatGPT Business or Enterprise plan (MCP remote servers require paid plans)
• An Ascend Gateway bearer token (get one) :::

Setup

1. Open ChatGPT → Settings → Connected Apps (or MCP Servers)
2. Click Add MCP Server
3. Enter the gateway URL:

   https://ascend-gateway-v5.ascendgtm.workers.dev/mcp

4. ChatGPT auto-discovers the OAuth server via /.well-known/oauth-authorization-server
5. Complete the OAuth flow — paste your bearer token on the consent page
6. 18 tools become available in your ChatGPT session

Test It

Ask ChatGPT:

List my connected APIs using the discover_apis tool

Authentication

On first connection, ChatGPT performs:

1. Dynamic Client Registration (RFC 7591) — registers itself with the gateway
2. PKCE Authorization (S256) — redirects you to the consent page
3. Token Exchange — receives a 90-day access token

Subsequent sessions reuse the stored token until it expires.

Differences from Claude

• Same 18 tools available (not 19 — count was corrected)
• Same response format and error codes
• ChatGPT may present tool results differently in the UI
• Response trimming (fields, format) works identically
• ChatGPT uses the same OAuth flow as Claude Web

Troubleshooting

Issue	Fix
"MCP not available"	Requires Business/Enterprise plan
"Authorization failed"	Verify bearer token with curl -H "Authorization: Bearer TOKEN" .../health
"Token expired"	Remove and re-add the MCP server to trigger new OAuth flow
Tool calls fail	Use discover_apis to check which providers are connected