Witness for ChatGPT

io.github.tfitzgerwitness/witness

Production proofs for breaking JSON Schema/MCP changes; UNKNOWN/NO_WITNESS_FOUND not compatible.

client:ChatGPT transport:streamable-http tools:1

Install Witness in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://witness-contractwitness-production.witness-test.workers.dev/mcp

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