SingleFax for ChatGPT

com.singlefax/mcp

Send a fax from Claude, ChatGPT, or Cursor. Upload a PDF, pay, get delivery status.

client:ChatGPT transport:streamable-http

Install SingleFax in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://singlefax.com/mcp

Custom connectors are a paid-plan feature and take a remote URL only. ChatGPT cannot run a packaged server locally. ChatGPT docs