ProofCheck for Gemini CLI

io.github.something-agent/proofcheck

Free x402 offer/receipt checker: verifies signatures and whether the signer fits the host.

client:Gemini CLI transport:streamable-http tools:5

Install ProofCheck in Gemini CLI

~/.gemini/settings.json · windows: %USERPROFILE%\.gemini\settings.json

{
  "mcpServers": {
    "proofcheck": {
      "httpUrl": "https://proofcheck.something-agent.workers.dev/mcp"
    }
  }
}

Gemini expands $VAR and ${VAR} inside env values, so a secret can live in your shell rather than this file. Gemini CLI docs