Receipt — sign an agent's work, verify it offline for ChatGPT

io.github.ecstatica/ggbank-receipt

Ed25519 receipts over work artifacts: issue and verify offline, no account, no chain, no network.

client:ChatGPT transport:streamable-http runtime:mcpb tools:2

Install Receipt — sign an agent's work, verify it offline in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://receipt.whirlwindcorp.com/mcp

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