NormAPI for ChatGPT

com.normapi/mcp

Validate, generate and read German e-invoices (XRechnung, ZUGFeRD) against the official KoSIT rules.

client:ChatGPT transport:streamable-http runtime:npm tools:4

Install NormAPI in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://normapi.com/mcp

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