@nickthelegend/fund402

Drop-in Axios interceptor for autonomous AI agents on Stellar. Automatically handles HTTP 402 Payment Required via Just-In-Time USDC loans.

Install

npm install @nickthelegend/fund402

Usage

import { withPaymentInterceptor, testnetConfig } from "@nickthelegend/fund402";

const agent = withPaymentInterceptor({
  ...testnetConfig(),
  agentSecretKey: process.env.AGENT_SECRET_KEY!,
  agentPublicKey: process.env.AGENT_PUBLIC_KEY!,
  vaultContractId: "CDXTW6IMQTPTWWBV7T5FYZZHXQFLWFXAQZHI32SHQS3YHKL6YLM7APD5",
  onEvent: (event) => console.log(event.type, event.data),
});

// One line — handles 402, borrows USDC, pays, retries, returns data
const { data } = await agent.get("https://your-fund402-vault-url/prices/XLM-USDC/spot");

Events

| Event | Description | |-------|-------------| | intercepted_402 | HTTP 402 received, starting JIT loan flow | | simulating_borrow | Calling simulate_borrow on Soroban (read-only) | | signing_transaction | Building and signing borrow_and_pay tx | | payment_sent | Transaction submitted to Stellar Horizon | | request_retried | Original request retried with payment-signature | | payment_confirmed | On-chain confirmation received |

Config

| Field | Description | |-------|-------------| | agentSecretKey | Agent's Stellar secret key (SXXX...) | | agentPublicKey | Agent's Stellar public key (GXXX...) | | vaultContractId | fund402 vault Soroban contract ID | | networkPassphrase | Stellar network passphrase | | horizonUrl | Stellar Horizon URL | | sorobanRpcUrl | Soroban RPC URL | | onEvent | Optional event callback |

Networks

import { testnetConfig, mainnetConfig } from "@nickthelegend/fund402";

// Testnet
const agent = withPaymentInterceptor({ ...testnetConfig(), ... });

// Mainnet
const agent = withPaymentInterceptor({ ...mainnetConfig(), ... });

Built for the Stellar Agents Hackathon 2026.