@latch-0xdivyanshh/sdk

Plug-and-play client for Latch — verifiable settlement for agent commerce on Avalanche. Let one agent pay another and release funds only when the work is verifiably correct, with a staked verifier set and slashing. This SDK is config-injected (no global env), so any agent — buyer or provider — can integrate in a few calls.

npm install @latch-0xdivyanshh/sdk viem

Quickstart

import { Latch } from "@latch-0xdivyanshh/sdk";

const FUJI = "https://api.avax-test.network/ext/bc/C/rpc";
const LATCH = "0xa5cA9c7920F22E1104215C430227756dEBBb2a09";
const USDC  = "0x5425890298aed601595a70AB815c96711a31Bc65";

Buyer — hire and pay for verified work

const buyer = new Latch({ rpcUrl: FUJI, account: BUYER_KEY, latch: LATCH, usdc: USDC });

// 1. create the job, committing the correctness policy hash up front
const { jobId } = await buyer.createJob({
  provider, amount: 5000n, bond: 1000n, policyCommitment, challengeWindow: 60,
});

// 2. sign the x402 / EIP-3009 USDC payment (no tx yet — this is the X-PAYMENT body)
const payment = await buyer.signPayment(jobId, 5000n);

// ...the provider does the work and a staked verifier scores it...

// 3. after the challenge window: pays the provider on PASS, refunds you + slashes on FAIL
await buyer.finalize(jobId);
await buyer.withdraw();          // pull any refund back to your wallet

Provider — sell work, bonded

const provider = new Latch({ rpcUrl: FUJI, account: PROVIDER_KEY, latch: LATCH, usdc: USDC });

await provider.acceptJob(jobId, 1000n);            // stake a bond (EIP-3009, approval-free)
const deliverable = await myAgent.run(task);       // your real agent logic
await provider.submitDeliverable(jobId, deliverable);

The bond is skin in the game: return well-formed garbage and the verifier scores it FAIL, refunding the buyer and slashing your bond. Do the work correctly and you're paid the amount minus a small protocol fee.

API

| Method | Role | What it does | |---|---|---| | createJob(p) | buyer | create the job + commit the policy hash; returns { jobId, tx } | | signPayment(jobId, amount) | buyer | sign the EIP-3009 payment (the x402 X-PAYMENT body) | | fundJob(jobId, payment) | facilitator | redeem a signed payment into escrow | | acceptJob(jobId, bond) | provider | stake a bond and take the job | | submitDeliverable(jobId, data) | provider | record the deliverable hash on-chain | | finalize(jobId) | anyone | settle after the challenge window | | withdraw() | buyer / provider | pull funds owed (refund or proceeds) | | withdrawable(addr?) / usdcBalance(addr?) | — | reads |

Funding is caller-bound and job-nonce-bound, so a payment can only land in the right escrow and can't be replayed. Verdicts are produced by a staked verifier committee (k-of-n quorum, slashed if overturned) — see the main project docs and the /security threat model.

Status

v0 on Avalanche Fuji. Built for the Avalanche agentic-payments work; mainnet awaits a third-party audit. The verifier policy types and the staked committee live in the main repo.