@trustline-agents/agent-sdk

Credit for AI agents, in a few lines. An agent uses this SDK to get an uncollateralized, revenue-underwritten credit line and draw/repay USDC on Stellar — autonomously, no human in the loop.

Borrowing power comes from the agent's proven revenue (on-chain x402 earnings + zkTLS-attested off-chain income), underwritten by the Fianza engine. Settles in USDC. Every agent's line is an isolated vault.

Install

npm install @trustline-agents/agent-sdk

New to Fianza? Read the onboarding kit first — it walks through getting a testnet Stellar account funded (XLM + USDC) before any of this will work, then runs this exact quickstart end to end with real command output. There's also a runnable copy of it at examples/quickstart.mjs.

Quickstart

import { FianzaAgent } from "@trustline-agents/agent-sdk";

// The agent holds its own Stellar key.
const tl = new FianzaAgent(process.env.AGENT_SECRET!, {
  apiBaseUrl: "https://trustline-rpxt.onrender.com", // the underwriting engine
  // contracts: { registry, creditLine, vault }  // optional; else read from /config
});

// 1. Register + get underwritten from your real revenue.
await tl.onboard();

// 2. See your line.
const { limitUsdc, aprBps } = await tl.creditLine();
console.log(`limit ${limitUsdc} USDC @ ${aprBps / 100}% APR`);

// 3. Borrow working capital, do the work, repay as revenue lands.
if (await tl.availableCreditUsdc() >= 5) {
  await tl.borrow(5);
  // ...spend on compute / APIs / data, deliver, get paid over x402...
  await tl.repay(5);
}

API

| Method | What it does | |---|---| | register() | Register the agent on-chain (one-time). | | underwrite({ skipProof?, fromLedger? }) | Run the full scoring pass (revenue → zkTLS proof → score → publish on-chain). | | onboard() | register() then underwrite(). | | creditLine() | { tier, limitUsdc, aprBps } derived live from the on-chain score. | | availableCreditUsdc() | Remaining drawable credit. | | vaultState() | Full isolated-vault accounting for this agent. | | borrow(usdc) / repay(usdc) | Draw / repay against the line. | | deposit(agent, usdc) | LP action — supply liquidity to an agent's isolated vault. | | usdcBalanceUsdc() | The agent's spendable USDC balance. | | payWithCredit(url, priceUsdc) | Draw-on-402 — pay for an x402 resource, auto-drawing any shortfall from the credit line first. Credit becomes invisible. | | revenue(fromLedger?) | Live x402 revenue index. |

On-chain writes are signed by the agent's own key; reads are simulate-only; scoring is delegated to the Fianza underwriting engine (the trusted underwriter in v1 — see the decentralization roadmap).

Draw-on-402 — credit that draws itself

// The agent just transacts. If it can't cover the paywall, the line covers it.
const res = await tl.payWithCredit("https://api.example.com/premium", 3, {
  maxDraw: 5, // optional cap per call
});
// → checks USDC balance, borrows only the shortfall, pays over x402, returns the Response.

Testnet today. Not financial advice; you are responsible for your agent's borrowing.