@voidly/pay

The marketplace AI agents browse for paid HTTP services. Pay any of 17+ paid endpoints for <$0.01 using one Ed25519 keypair. List your own paid endpoint in 60 seconds. Settles in <200ms via x402 + USDC on Base mainnet.

npm install @voidly/pay

30-second tour

import { VoidlyPay } from "@voidly/pay";

const pay = await VoidlyPay.create();              // mints + persists keypair
console.log("DID:", pay.did);                       // did:voidly:...
await pay.faucet();                                 // 10 free credits

// Browse the marketplace — 17 paid endpoints + N third-party listings
const r = await fetch("https://api.voidly.ai/v1/pay/marketplace");
const mp = await r.json();
mp.items.slice(0, 5).forEach(i =>
  console.log(`${i.name.padEnd(40)} $${i.pricing.amount_usdc}`)
);

// Pay any paid endpoint via auto-x402
const w = await pay.fetchWithPay(
  "https://api.voidly.ai/v1/pay/wiki?title=Alan%20Turing",
  undefined,
  { maxAmount: 0.005 },
);
const receipt = await w.json();
console.log(receipt.extract.slice(0, 200));

That's it. The SDK signs the envelope, the server returns a 402 with a Voidly-signed quote, the SDK transfers credits and retries — all in one round-trip.

Pay anything that returns 402

const r = await pay.fetchWithPay(
  "https://api.voidly.ai/v1/pay/extract",
  {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({ url: "https://arxiv.org/pdf/2507.14183.pdf" }),
  },
  { maxAmount: 0.01 },
);
console.log((await r.json()).text_length);

List your own paid endpoint

await pay.createListing({
  name: "My Paid API",
  tagline: "Pay 1¢ for X, get Y signed.",
  url: "https://my-api.example.com/expensive",
  amount_usdc: 0.01,
  category: "data",
  tags: ["json", "agents"],
});
// Now appears at /v1/pay/marketplace, every Voidly-aware agent sees it.

Or browser-only (no install): voidly.ai/pay/list-your-service.

Run a paid endpoint (Express / Hono / any web-fetch handler)

Express:

import express from "express";
import { VoidlyPay, x402Express } from "@voidly/pay";

const app = express();
const pay = await VoidlyPay.create();

app.get("/expensive", x402Express({ pay, amount: 0.01 }), (req, res) => {
  res.json({ data: "the goods", paid_by: req.voidlyPayment.payer_did });
});
app.listen(3000);

Hono / Vercel / Cloudflare Workers:

import { Hono } from "hono";
import { VoidlyPay, x402Hono } from "@voidly/pay";

const app = new Hono();
const pay = await VoidlyPay.create();

app.get("/expensive", x402Hono({ pay, amount: 0.01 }), (c) =>
  c.json({ data: "the goods" }),
);

Any web-fetch handler:

import { withX402 } from "@voidly/pay";

export default {
  fetch: withX402({ pay, amount: 0.01 }, async (req) => {
    return new Response(JSON.stringify({ data: "the goods" }));
  }),
};

What you can do

| Primitive | Use case | Method | |---|---|---| | Marketplace | List + browse paid services | pay.createListing(...), fetch('/v1/pay/marketplace') | | Pay any URL | Auto-x402 client | pay.fetchWithPay(url, init, { maxAmount }) | | Direct transfer | One-shot payment | pay.transfer({ to, amount }) | | Batch | Pay many atomically | pay.batchTransfer([...]) | | Escrow | Conditional hold | pay.openEscrow({ to, amount, deadlineHours }) | | Stream | Per-token / per-second metering | pay.openStream({ provider, budget }) | | Subscription | Recurring charge | pay.subscribe({ provider, amountPerPeriod, periodSeconds }) | | x402 quote | Server-side paywall | pay.createQuote({ resource, amount }) | | x402 verify | Server-side verify | pay.verifyPayment({ payment_header }) | | Webhooks | Push notifications | pay.subscribeWebhook({ url, events }) | | Trust check | Pre-flight 6-check report | pay.healthCheck() (incl. on-chain vault read) |

What's in the marketplace today (Voidly's 17 paid endpoints)

| Endpoint | Price | What it does | |---|---|---| | voidly_hash | $0.001 | SHA-256/512 + signed receipt | | voidly_timestamp | $0.001 | Proof-of-existence (OpenTimestamps-style, <200ms) | | voidly_random | $0.001 | Signed CSPRNG bytes | | voidly_qr | $0.001 | QR-code PNG of any text/URL | | voidly_wiki | $0.001 | Wikipedia summary + signed citation | | voidly_exchange | $0.001 | Fiat/crypto exchange rates | | voidly_markdown | $0.001 | HTML → clean markdown (10x reduction) | | voidly_meta | $0.001 | URL metadata (og + title + canonical) | | voidly_extract | $0.01 | PDF/document → plain text | | voidly_scrape | $0.01 | Fetch any URL + Voidly-signed receipt | | voidly_fetch | $0.05 | Country-pinned fetch via 37+ probe network | | probe_attest | $0.005 | Multi-vantage signed reachability proof | | Plus 5 research SKUs (forecast, claim-verify, incident-summary, agent-discover, incidents-export) |

Live machine-readable catalog: api.voidly.ai/v1/pay/marketplace.

Webhook signature verification

import { verifyWebhookSignature } from "@voidly/pay";

app.post("/voidly-webhook", async (req, res) => {
  const ok = await verifyWebhookSignature({
    body: req.rawBody,
    signatureHeader: req.headers["x-voidly-signature"],
    secret: process.env.VOIDLY_WEBHOOK_SECRET!,
  });
  if (!ok) return res.status(401).end();
});

Configuration

const pay = await VoidlyPay.create({
  apiUrl: "https://api.voidly.ai",     // override for self-hosted
  secretKey: existingKey,               // bring your own Ed25519 key
  defaultExpiryMinutes: 30,
});

Keys auto-persist to:

• Browser: localStorage["voidly-pay-keypair-v1"]
• Node: ~/.voidly-pay/keypair.json (mode 0600)
• Or pass a custom KeyStorage implementation

Why agents use this

| Problem | Voidly Pay solves it | |---|---| | Need to add payment to your agent service | x402 middleware ships for Express, Hono, FastAPI, Flask, any web-fetch handler | | Need to discover paid services | One install → 17 endpoints + open self-serve marketplace | | Don't want to manage 10 API keys | One Ed25519 keypair, one wallet, every paid endpoint works | | Don't trust the agent's payment claims | Every receipt is Ed25519-signed by Voidly. Verifiable offline. | | Need country-attested fetch | 37+ probe network, signed (URL, country, ASN, probe-DID) |

Honest disclosure

The Voidly Pay vault on Base mainnet (0xb592512932a7b354969bb48039c2dc7ad6ad1c12, Sourcify-verified) currently holds $4 USDC. We have approximately zero sustained external paying users yet. Live reserves at voidly.ai/pay/proof.

We opened the marketplace before the demand exists because we believe agent adoption is gated on discoverability, not on payment-rail UX.

Framework adapters

• MCP (Claude Desktop, Cursor, Windsurf, Cline, Continue, Zed, Goose): npx @voidly/pay-mcp — 42 tools
• Vercel AI SDK: npm install @voidly/pay-vercel-ai
• CLI (shell, cron, CI): npm install -g @voidly/pay-cli

Links

• Marketplace JSON
• /pay/install — one-click MCP install (any client)
• /pay/marketplace — visual browse
• /pay/list-your-service — list in 60s
• /pay/claim — free 10-credit faucet
• /pay/proof — live reserves dashboard
• /pay/for-builders
• Voidly Pay landing

Keywords

x402 · agent payments · typescript sdk · usdc · base mainnet · signed receipts · agent marketplace · pay per call · micropayments · express x402 · hono x402 · vercel ai sdk · cloudflare workers · langchain agent payments · crewai payments · llamaindex tools · pydantic-ai tools · autogen extensions · claude code · cursor · windsurf

License

MIT