Postmark for ChatGPT

io.github.pipeworx-io/postmark

Postmark MCP.

client:ChatGPT transport:streamable-http

Install Postmark in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://gateway.pipeworx.io/postmark/mcp

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