@fretumai/express

Drop-in Fretum paymentMiddleware for x402-express. Same signature as x402-express — adds compliance, 0xSplits syndication, and dual listing on the Fretum marketplace + Agentic.Market.

Installed as @fretumai/express — imports are from '@fretumai/express'.

Install

npm install @fretumai/express @fretumai/facilitator

Quick Start

import express from "express";
import { paymentMiddleware } from "@fretumai/express";
import { facilitator } from "@fretumai/facilitator";

const app = express();

app.use(paymentMiddleware(
  "0xYourMerchantPayoutAddress", // raw EOA is fine — auto-wrapped in 0xSplits
  {
    "POST /lead-research": {
      price: "$1.00",
      network: "base",
      config: {
        name: "Lead Research",
        description: "Dallas-area B2B prospect enrichment",
        discoverable: true,
        inputSchema: { /* JSON Schema */ },
        outputSchema: { /* JSON Schema */ },
      },
    },
  },
  { facilitator }
));

app.post("/lead-research", (req, res) => {
  // ...do the work...
  res.json({ leads: [] });
});

app.listen(3000);

What Fretum adds over plain x402-express

1. 0xSplits auto-wrap — Pass a raw merchant EOA; we deploy (or resolve) an immutable 0xSplits contract that pays 98% to the merchant and 2% to the Fretum treasury, then hand that split address to x402 as payTo. No custody, no money-transmitter risk.
2. Dual listing — Every discoverable: true route is mirrored to fretum.ai/marketplace and optionally syndicated to Coinbase's Agentic.Market. Devs get distribution without extra work.
3. Graceful degradation — If the Fretum API is unreachable, the middleware falls through to raw x402-express behavior so your server never hard-fails on our outages.

Configuration

Environment variables:

FRETUM_API_BASE   default: https://api.fretum.ai
FRETUM_API_KEY    optional — required for listings/compliance

Or pass options directly:

paymentMiddleware(payTo, routes, {
  facilitator,
  fretumApiBase: "https://api.fretum.ai",
  fretumApiKey:  process.env.FRETUM_API_KEY,
  autoWrapSplit: true,   // default true
  syncListings:  true,   // default true
  merchantMetadata: { merchantId: "mcf-agentic" },
});

Advanced

import { fretumClient } from "@fretumai/express";

const client = fretumClient();
const split = await client.resolveSplit("0xMerchant", "base");

License

MIT — Cameron Fagan / MCF Agentic