# Backfill Fetch — web pages as markdown, paid per fetch

Backfill Fetch turns a web page into clean markdown for agents and scripts.
POST a URL; the service fetches it (a plain fetch first, with escalation to
a rendered fetch when the plain one returns a bot wall or a JavaScript
shell) and returns the readable content as markdown. Fetched pages are
cached for seven days.

Endpoints:
- POST /v1/fetch — JSON body { "url": "...", "mode": "auto"|"plain"|"render",
  "include_html": false }. Response JSON: { url, status ("ok"|"blocked"|"error"),
  markdown, cached, fetched_at, charged }.
- POST /v1/extract — Backfill Extract: JSON body { "url": "...",
  "schema": { ... a JSON Schema object ... }, "mode": "auto"|"plain"|"render" }.
  The page is fetched the same way and its data is returned as JSON matching
  the schema. Response JSON: { url, status, data, cached, fetched_at, charged }.

Pricing (x402 protocol v2, USDC on Base, no account or API key):
- Plain fetches are free within a per-source daily allowance (50 per day).
- A cached page costs $0.005 (the first 10 cache hits per source per day are free).
- A fresh rendered fetch costs $0.05.
- A fresh structured extraction costs $0.15. A repeated extraction of the
  same page with the same schema (a cached result) costs $0.05. Extraction
  has no free allowance.
- Payment is verified before the fetch and settled only after content has
  been extracted and is ready to serve. A failed fetch is never charged.

Payment flow: send the request without a payment header and read the 402
response — it carries the payment requirements (also in the PAYMENT-REQUIRED
header). Pay with an x402 client and resend with the PAYMENT-SIGNATURE
header; the payment is verified, the page is fetched, and the payment is
settled only when the content is delivered, with a PAYMENT-RESPONSE header.

Machine-readable API description: /openapi.json
x402 discovery document: /.well-known/x402
MCP endpoint: POST /mcp (JSON-RPC 2.0) exposes two tools: fetch_page
(the fetch endpoint, same pricing) and extract_data (the extract
endpoint). A call that would require payment returns an error directing
the caller to the HTTP endpoint — payment is never attempted over MCP.
Human page: https://backfill.top/