12 pay-per-call micro-APIs for AI agents — settle USDC on Base mainnet with the x402 protocol. No signup, no API key: your agent just pays per request.
| Endpoint | Price | What it does |
|---|---|---|
POST /extract |
$0.002 | Turn any web page into clean, LLM-ready Markdown. Fetches the URL, isolates the main article with Mozilla Readability (stripping nav, ads and boilerplate), a… |
POST /metadata |
$0.001 | Extract structured metadata from any web page: title, description, author, published date, language, OpenGraph image, canonical URL, favicon and estimated re… |
POST /unfurl |
$0.001 | Generate a compact link-preview card (title, description, image, site name) from a URL using OpenGraph/Twitter tags — for chat unfurls, social previews and a… |
POST /rss-to-json |
$0.001 | Convert an RSS 2.0 or Atom feed URL into clean, normalized JSON (title, link, published date, summary per item). For agents monitoring news, blogs and conten… |
POST /pdf-to-markdown |
$0.003 | Fetch a PDF by URL and extract its text as Markdown, with page count and word count. Lets AI agents read PDF documents, reports and papers. (Text-based PDFs;… |
POST /qr |
$0.001 | Generate a QR code (PNG data-URI or SVG) for any text or URL. Simple, instant utility endpoint. |
POST /convert |
$0.001 | Convert between common text formats: Markdown↔HTML and CSV↔JSON. Handy data-plumbing utility for agents and pipelines. |
POST /token-price |
$0.002 | Real-time crypto spot price for any asset (BTC, ETH, SOL, …) in USD or another currency. Live market data feed for AI trading and finance agents. |
POST /wallet-balance |
$0.003 | On-chain native + ERC-20 token balances for any EVM address across Ethereum, Base, Arbitrum, Optimism and Polygon. For wallet-tracking and DeFi agents. |
POST /ens |
$0.002 | Resolve an ENS name to an address, or reverse-resolve an address to its ENS name (Ethereum mainnet). Identity lookups for crypto agents. |
POST /gas |
$0.001 | Current gas price (gwei) on Ethereum, Base, Arbitrum, Optimism or Polygon. Lets agents time and price on-chain transactions. |
POST /token-info |
$0.002 | ERC-20 token metadata (name, symbol, decimals, total supply) for any token contract across major EVM chains. On-chain reference data for agents. |
Every endpoint is free to probe (it answers 402 Payment Required with the x402 challenge). Pay the quoted USDC and retry — any x402 client does this for you automatically:
# 1) See the price (free) — returns HTTP 402 with the x402 challenge
curl -i -X POST http://x402.valkyry.fr/extract -H 'content-type: application/json' -d '{"url":"https://example.com"}'
# 2) Pay & call automatically with an x402 client (Node):
import { wrapFetchWithPayment } from "@x402/fetch";
const fetchWithPay = wrapFetchWithPayment(fetch, walletClient);
const res = await fetchWithPay("http://x402.valkyry.fr/extract", {
method: "POST",
headers: { "content-type": "application/json" },
body: JSON.stringify({ url: "https://example.com" }),
});
console.log(await res.json());
Built on the official x402 V2 protocol · facilitator settles on-chain · this service holds only a receiving address. See /openapi.json for full request/response schemas.