@arbiterlabs/proxy

A local sidecar that pays for Arbiter calls, so agents in any language can use it.

ARBITER_URL=https://arbiter-hs23.onrender.com \
ARBITER_PRIVATE_KEY=base64-64-byte-algorand-key \
ARBITER_MAX_SPEND_USD=10 \
npx @arbiterlabs/proxy

Then call it over loopback, unpriced:

curl -X POST http://127.0.0.1:4030/judge/counterparty \
  -H 'content-type: application/json' \
  -d '{"address":"...","expectedAsset":"31566704"}'

Why this exists

Paying x402 on Algorand needs an AVM scheme client, and that exists only in TypeScript today. The published Python packages do not provide one — x402 ships no AVM client, and x402-avm ships none either despite the name. A Python agent therefore cannot construct an Algorand x402 payment at all.

It is also the better arrangement where a native client does exist: one process holds the funded key and enforces one budget, instead of every agent process carrying a copy of both.

Endpoints

POST /judge/transaction · POST /judge/counterparty · POST /judge/human · GET /budget · GET /health

Security

Binds to 127.0.0.1 only — it is a paying oracle and must not be reachable from the network. Set ARBITER_PROXY_TOKEN if other local processes should not be able to spend. A budget error returns 429, so callers back off rather than retry into the cap.

Paying

Calls are settled per request in USDC on Algorand over x402. There is no API key and no account — payment is the authentication.

Your payer account needs USDC and must be opted in to the USDC asset. On Algorand a transfer to an account that has not opted in is rejected outright, so an un-opted-in payer cannot pay at all. Fees are sponsored by the facilitator, so the payer does not need ALGO.

| Route | Price | |---|---| | Transaction verdict | $0.002 | | Counterparty verdict | $0.01 | | Human judgment | $0.25 |

Full documentation: https://arbiter-hs23.onrender.com/docs

Licence

MIT