Peek API

Turn any URL into clean link-preview metadata or LLM-ready markdown. No signup. No API key. Free for 50 calls a day, then pay per call in USDC — your agent pays automatically over x402.

50/day free $0.001 / preview $0.002 / markdown USDC on Base Zero-config for AI agents

Try preview → Try markdown →

Endpoints

Endpoint	Returns	Price
`GET /v1/preview?url=`	title, description, image, favicon, site name, canonical	$0.001
`GET /v1/markdown?url=`	full page as clean markdown	$0.002
`GET /v1/pricing`	machine-readable pricing	free
`GET /v1/health`	liveness	free

Quick start

It is a plain GET. Nothing to install, nothing to register.

curl "https://smeltworks.com/peek/v1/preview?url=https://news.ycombinator.com"

{
  "url": "https://news.ycombinator.com",
  "title": "Hacker News",
  "description": "...",
  "image": "https://news.ycombinator.com/y18.svg",
  "siteName": "Hacker News",
  "favicon": "https://news.ycombinator.com/favicon.ico"
}

Paying (for agents)

The short version

Past the free tier the API answers HTTP 402 with a standard x402 challenge. Any x402-capable client pays it and retries automatically — there is no account to create and no invoice to reconcile.

import { withPaymentInterceptor } from "x402-axios";
import axios from "axios";

const api = withPaymentInterceptor(
  axios.create({ baseURL: "https://smeltworks.com/peek" }),
  account,                    // your viem account, funded with USDC on Base
);

const { data } = await api.get("/v1/markdown?url=https://example.com");

Settlement is USDC on Base mainnet, straight to the seller address in the challenge. Discovery document: /.well-known/x402.

Paying (for humans)

Peek API Pro — $9 one-time

25,000 calls. No expiry, no subscription, no dashboard. If you'd rather not touch crypto, buy a prepaid key with a card. Use it as an X-API-Key header (or ?key=) on any endpoint and the free-tier limit no longer applies.

Buy a Pro key — $9

Checkout is Stripe. After paying, email the receipt to [email protected] and your key comes back by reply — keys are issued against the paid receipt. Verify a key any time at GET /v1/key/check.

curl -H "X-API-Key: pk_your_key_here" \
  "https://smeltworks.com/peek/v1/markdown?url=https://example.com"

Why this one

Cheapest in its class. Comparable URL→markdown endpoints run $0.003–$0.015 per call. This is $0.002, and metadata-only is $0.001 — you should not pay markdown prices when all you need is a title and an image.

No onboarding tax. No dashboard, no key rotation, no minimum spend. An agent that has never seen this service can discover it, call it, pay it, and move on.

For machines

/.well-known/x402 · /llms.txt · /openapi.json · /v1/pricing

Limits

Free tier is 50 requests/day per IP. Markdown responses are capped at 200,000 characters. Requests to private/internal network addresses are refused. Redirects are followed to a final canonical URL.