@arbiterlabs/sdk

Ask whether an action is safe before your agent takes it.

An AI agent about to sign a transaction cannot tell a legitimate one from a transaction that quietly hands away its wallet. This client asks Arbiter and gets back allow, warn, block or escalate — with reasons — in a few hundred milliseconds.

npm install @arbiterlabs/sdk

import { ArbiterClient } from "@arbiterlabs/sdk";

const arbiter = new ArbiterClient({
  baseUrl: "https://arbiter-hs23.onrender.com",
  privateKey: process.env.ALGO_KEY,   // base64 64-byte Algorand key
  maxTotalSpendUsd: 10,
});

const verdict = await arbiter.judgeTransaction({ transaction, signer });

if (verdict.decision !== "allow") {
  console.warn(verdict.findings.map((f) => f.title));
  return;                              // do not sign
}

Algorand and EVM chains share one method:

await arbiter.judgeTransaction({
  chain: "evm",
  chainId: 1,
  transaction: { to: token, data: approveCalldata },
});

Spend limits are part of the client

An agent stuck in a retry loop against a paid endpoint is a wallet-draining bug, so the caps are enforced in the payment selector — before anything is signed — rather than left to you to remember.

new ArbiterClient({
  maxPricePerCallUsd: 0.05,   // refuse any single call above this
  maxTotalSpendUsd: 10,       // lifetime cap for this client
});

Exceeding either throws ArbiterBudgetError, catchable distinctly from a network or payment failure.

The verdict

Every route returns the same shape, so you integrate once.

{
  decision: "block",     // allow | warn | block | escalate
  risk: 100,             // 0-100
  confidence: 1,         // 0-1
  findings: [{ code, severity, title, detail, source }],
  evidence: { /* the decoded transaction, the account record */ },
  meta: { latencyMs: 359, degraded: false },
}

escalate means not enough evidence was gathered to decide. It is not approval — treat it as "ask a human". meta.degraded: true means an upstream was unreachable and the verdict is partial; the decode rules that catch critical severities still ran.

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