The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Penniless Data Utilities listing page.
Nine deterministic data and lookup tools for AI agents, paid per call in USDC. REST advertises both native MPP and x402; MCP uses x402 v2. No accounts, no API keys, no rate-limit tiers. Every tool is pure computation or a keyless public lookup — none of them call another AI model, so results are reproducible.
/health, /openapi.json, /llms.txt, /.well-known/x402$0.001 USDC per call. REST advertises native MPP plus x402 v2 (eip155:8453, scheme exact); MCP uses x402 v2.
Base x402 settlements are verified by the free-tier PayAI facilitator. Native MPP is negotiated by mppx. Recipient (payTo): 0x3D98800c64C345950E1eAaa076D88C12d1BF5F37.
Any MCP client that speaks streamable HTTP can connect directly:
The transport is stateless — no session id is issued or required, and every
request is independent. initialize and tools/list are free. An unpaid
tools/call returns an x402 payment-required payload in result.content[0].text
(and result.structuredContent); attach the signed payment as
params._meta["x402/payment"] and repeat the call.
If you use an x402-aware MCP client, @x402/mcp handles that exchange for you.
| MCP name | REST path | Arguments | Returns |
|---|---|---|---|
repair_json | POST /repair/json | {input} | repaired JSON + which fixes applied |
yaml_to_json | POST /yaml/tojson | {input} | parsed value + warnings |
cron_next_run | POST /cron/nextrun | {expr, after?} | next UTC fire time |
text_diff | POST /diff | {old, new, context?} | unified diff + counts |
text_extract | POST /text/extract | {input, numbers?, codeBlocks?} | text, title, headings, links, URLs, emails |
domain_whois | POST /domain/whois | {domain} | registrar, statuses, expiry, nameservers, DNSSEC |
dns_lookup | POST /dns/lookup | {domain, type?} | DoH answers for A/AAAA/CNAME/MX/TXT/NS/SOA/PTR/SRV/CAA |
github_repo_stats | POST /github/repo-stats | {repo} | stars, forks, open issues, language, license |
email_validate | POST /email/validate | {email} | syntax + live MX deliverability |
POST /diagnose is free: it classifies what is wrong with a malformed JSON
payload without returning the repaired output, so a caller can check whether
paying is worthwhile before paying.
Any x402 v2 client works. With the reference TypeScript client and a viem account:
wrapFetchWithPayment handles the 402 round-trip: it receives the requirement,
signs the USDC authorization, retries, and only returns a 200 once the
facilitator has settled.
Environment (set in wrangler.toml): X402_NETWORK, X402_FACILITATOR,
X402_PRICE, X402_PAY_TO. Production also has an encrypted Cloudflare secret
MPP_SECRET_KEY used only to authenticate MPP challenges. Wallet private keys are
never deployed to the Worker.
GitHub: @danielarif26