Lettera for ChatGPT

dev.lettera/relay

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client:ChatGPT transport:streamable-http tools:7

Install Lettera in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://api.lettera.dev/mcp

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