ExpressNumber for ChatGPT

com.expressnumber/mcp

Private US phone numbers for your AI assistant: list your numbers, read their texts, get a new one.

client:ChatGPT transport:streamable-http

Install ExpressNumber in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://www.expressnumber.com/api/mcp

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