ProofFetch: cited web evidence for agents
Free check with a text preview (about the first 1,000 characters; short pages come back whole). Full text costs 1¢ a page either way: 500 pages for $5 by card, or $0.50 for 50 if your agent pays automatically through Stripe (the page it asked for, plus a key for 49 more).
Try the preflight · Current offer · OpenAPI · Support
For agents: llms.txt · A2A agent card · connection guide · MCP registry name io.github.equinoxaifinance-rgb/proof-fetch
Before paying: terms · privacy · refunds
This repository contains documentation and small client examples only. It does not contain the extraction engine, a payment credential, or a way to obtain the paid paragraphs free.
Start here
- Inspect a URL before giving it to an agent.
- Handle a payment challenge without accidental retries.
- With Node 22 or later, run
node examples/preflight.mjs https://example.comfrom this repository. The example makes no payment. - In n8n, inspect free metadata and stop before payment using the bounded client workflow.
This repository's documentation, discovery metadata and examples, including the n8n wrapper and guide in guides/n8n, are MIT licensed under the root LICENSE. The MIT licence does not cover the ProofFetch extraction engine or the hosted service at prooffetch.tryneverclosed.com: their source is not in this repository and is not licensed or distributed here. Paid paragraphs, upstream material, credentials and account or payment rights keep their own terms.
Agent skill
skills/cited-web-evidence/SKILL.md teaches an agent when and how to use ProofFetch: preflight first, pay only with the user's approval, and cite paragraph IDs. Install it into Claude Code, Cursor, Codex or another skills-aware agent with npx skills add equinoxaifinance-rgb/proof-fetch-docs --skill cited-web-evidence.
Connect an MCP client
Use Streamable HTTP at https://prooffetch.tryneverclosed.com/mcp (the original https://proof-fetch-agent-api.neoaethel.workers.dev/mcp keeps working). In Claude Code: claude mcp add --transport http proof-fetch https://prooffetch.tryneverclosed.com/mcp. Its free tools are proof_fetch_preflight and proof_fetch_offer. It also lists proof_fetch_evidence, which returns the paid text and needs a ProofFetch card-pack key sent as Authorization: Bearer <key>. MCP Registry manifest: server.json (io.github.equinoxaifinance-rgb/proof-fetch). The free tools never return the paid page text. Clients paying through Stripe MPP use POST /v1/evidence; each $0.50 payment returns the page plus callBundle.apiKey for 49 more.
What you receive
Free preflight: fetch metadata, document statistics, content/raw hashes and deterministic prompt-injection indicators. Paid fulfillment adds paragraph IDs, text and a payment receipt. A hash identifies bytes; it does not certify that a source is true. An unflagged page is not a safety guarantee.
Supported: public HTML, XHTML, text and JSON, at most 1 MiB and five redirects. No login, cookies, caller headers, browser rendering or private-network destinations. Inspect the live offer for current limits before integration.
Design-partner invitation
Building a research agent and struggling to preserve citations or recover paid requests? Open a support case.
Documentation prepared with AI assistance and checked against the public API. ProofFetch is operated by Neverclosed (https://tryneverclosed.com). Support: [email protected] or https://prooffetch.tryneverclosed.com/policies/support