35 pay-per-call tools for AI agents, paid with x402 (USDC on Solana and Base): web page to markdown, HTML tables, prompt-injection detector, agent-readiness audit, agent mailboxes, DNS/RDAP/email checks, dependency vulnerabilities, Polymarket, SEC EDGAR, Federal Register, papers, clinical trials and official Mexican data. No API keys.
Scored across 37 tools
Most tools target a distinct data source and verb (deps_check vs deps_audit differ by single vs bulk; polymarket_market by id vs polymarket_markets by query; empresas vs empresas_buscar vs empresas_cerca), and the descriptions make those boundaries explicit. The main soft spots are the meta/onboarding trio catalog, health and x402_find, which an agent could plausibly confuse, and the singular/plural polymarket pair, which relies on descriptions rather than names to disambiguate.
All names are snake_case, which is a real plus, but the convention is mixed: English noun_verb (agents_readiness, email_validate, web_read, deps_audit), Spanish noun_verb (curp_validar, rfc_validar, empresas_buscar) and bare nouns (dns, domain, cp, iva, uma, banxico, empresas, health, catalog). Verb placement also flips (curp_validar vs sat_cfdi_verificar) and the language of the vocabulary changes by domain, so names are readable but not predictable from a pattern.
37 tools is well beyond a well-scoped surface, even though each one is a genuinely distinct paid endpoint rather than a duplicate; there is little redundancy to prune. The problem is selection cost: an agent must scan three Mexican business tools, two dependency tools, two SEC tools, three messaging tools and three meta tools before picking, and per-call pricing adds a decision on top of the choice.
The domain is a pay-per-call data marketplace, and coverage is broad: identity/validation, Mexican geo and tax, DNS/domain/email intel, web extraction, academic and government search, SEC filings, prediction markets and token checks. Remaining gaps are modest — no generic geocoding or address-to-coordinate lookup, messaging has create/send/read but no mailbox listing or delete, and no balance/usage or payment-receipt tool — all workable around via catalog and the existing endpoints.
Agent-readiness audit of a website: score 0-100 and grade A-F from 18 checks fetched in parallel. Covers robots.txt rules for GPTBot, ClaudeBot, PerplexityBot, Google-Extended, CCBot and Bytespider; llms.txt; sitemap.xml; openapi.json, ai-plugin.json, MCP and x402 discovery files; and the page itself: JSON-LD types, Open Graph, title, meta description, lang, headings, text-to-HTML ratio, content visible without JavaScript, HTTPS and response time. Includes concrete recommendations. Price: $0.01 USDC per call (x402).
Inputs: url (required).
Latest value of an official Banco de México series: fix (USD/MXN FIX rate), udis, tiie28, tasa-objetivo, or any raw SIE series ID. Returns the date and value as published. Price: $0.003 USDC per call (x402).
Inputs: serie (required).
Free. Lists every tool with its price in USD, the accepted networks and how x402 payment works over MCP.
Inputs: no named parameters.
Clinical trial search on ClinicalTrials.gov (500K+ registered studies worldwide) by condition, intervention, recruitment status, country and phase. Each study includes NCT ID, title, status, phase, conditions, interventions with type, lead sponsor, enrollment, start and completion dates, number of sites, countries, registry URL and a brief summary (up to 600 chars). Returns the total match count and up to 50 studies per call. Price: $0.005 USDC per call (x402).
Inputs: limit, phase, status, country, +2 more.
Mexican postal code lookup from the national catalog of Correos de México: state, municipality, city and every neighborhood (colonia) with its settlement type. Price: $0.003 USDC per call (x402).
Inputs: cp (required).
Validates a Mexican CURP: 18-character structure, check digit, and decodes sex, birth date and state of birth. Offline. Price: $0.002 USDC per call (x402).
Inputs: curp (required).
Vulnerability audit of up to 200 pinned dependencies in one call against the OSV database (npm, PyPI, Go, Maven, Cargo, NuGet). Accepts a package list or a package.json (dependencies and devDependencies, range prefixes stripped). Returns, per package, every known advisory with CVE aliases, CVSS score and level, fixed versions and URL, plus a severity summary (critical, high, medium, low, unknown), the count of vulnerable packages and any specs that could not be pinned. Price: $0.02 USDC per call (x402).
Inputs: packages, ecosystem, package_json.
Security and freshness check for one package version across npm, PyPI, Go, Maven, Cargo and NuGet: known vulnerabilities from OSV with CVE aliases, CVSS score and level, fixed versions and advisory URL; latest version, versions behind, publish date, licenses, deprecation flag and repository links from deps.dev; and a one-word verdict (ok, outdated or vulnerable). Version defaults to the latest release. Price: $0.005 USDC per call (x402).
Inputs: name (required), version, ecosystem.
Mexican banking business days per the CNBV calendar: whether a date is a business day, the next and previous business day, and a date plus N business days. Price: $0.002 USDC per call (x402).
Inputs: dias, fecha.
Full DNS profile of a domain in one call: A, AAAA, CNAME, MX, NS, TXT, SOA and CAA records, SPF and DMARC parsed (policy, all-mechanism, reporting address), DNSSEC validation flag, and inferred providers for DNS hosting, email and web hosting. Resolved over DNS-over-HTTPS with a public resolver; accepts bare hostnames or full URLs. Price: $0.003 USDC per call (x402).
Inputs: domain (required).
Domain registration record from the authoritative registry via RDAP (the successor to WHOIS): whether the domain is registered, registrar name and IANA ID, abuse contact, creation, last-change and expiration dates, days until expiry, EPP status codes, registry nameservers and DNSSEC delegation. Covers gTLDs and the ccTLDs that publish RDAP. Price: $0.005 USDC per call (x402).
Inputs: domain (required).
Email address check without sending mail: RFC-style syntax validation, domain deliverability from MX (or A/AAAA fallback) over DNS-over-HTTPS, mail exchangers, disposable-domain and free-provider detection, role-based local parts (info, support, noreply), typo suggestion for common providers, plus-tag and canonical form (Gmail dots and tags removed), with a 0-100 score and a valid/risky/invalid verdict. Price: $0.002 USDC per call (x402).
Inputs: email (required).
Full record of one Mexican business from INEGI's DENUE by establishment ID: identification, activity, address, contact, size, type and coordinates. Price: $0.02 USDC per call (x402).
Inputs: id (required).
Searches Mexican businesses in INEGI's DENUE directory (5M+ establishments) by name or keyword, optionally filtered by state. Returns name, legal name, activity, address, postal code, phone, email, website, size and coordinates. Price: $0.05 USDC per call (x402).
Inputs: q (required), fin, estado, inicio.
Finds Mexican businesses near a coordinate using INEGI's DENUE: keyword plus latitude, longitude and radius up to 5,000 m. Same fields as the name search. Price: $0.05 USDC per call (x402).
Inputs: q (required), lat (required), lng (required), metros.
US Federal Register documents (final rules, proposed rules, notices, presidential documents) matching a full-text query, newest first, with optional filters by agency, document type and publication date. Each document includes number, title, type, abstract, agencies, publication date, effective date, comment deadline, HTML and PDF URLs and the FR citation, plus the total number of matches. Source: Federal Register API. Price: $0.003 USDC per call (x402).
Inputs: q, type, limit, since, +1 more.
Prompt-injection detector for text an agent is about to feed to a model: tool results, scraped pages or user input. Rules and heuristics only, no LLM, fast and deterministic. Returns risk 0-1, a clean/suspicious/malicious verdict, the categories found (instruction override, role hijack, prompt or data exfiltration, tool abuse, hidden Unicode, encoded payloads, fake chat delimiters, ES/PT/FR/DE/IT variants) with evidence snippets, and a sanitized copy. POST with JSON {text, context} also works. Price: $0.002 USDC per call (x402).
Inputs: text (required), context.
Free. Payment network, facilitator and configured data sources.
Inputs: no named parameters.
Mexican VAT (IVA) and retention rates: general 16%, northern/southern border 8%, 0% and exempt categories, plus ISR and IVA retention rates for professional services and leases. Price: $0.001 USDC per call (x402).
Inputs: no named parameters.
Creates a private mailbox for agent-to-agent messaging and returns its 22-character id plus a secret read key. Any agent that knows the id can deliver messages to it; only the read key can read them. The mailbox lives 30 days; messages are kept 7 days, newest first, up to 500. Optional label for bookkeeping. Price: $0.005 USDC per call (x402).
Inputs: label.
Reads the newest messages of an agent mailbox; requires the mailbox id and its read key (401 otherwise). Returns up to limit messages (default 20, max 100) with id, from, body, reply_to and sent_at. Reads are non-destructive unless ack=true, which removes the returned messages so the next read continues where this one left off. A public demo mailbox (demo000000000000000000, key demo) is available for testing. Price: $0.001 USDC per call (x402).
Inputs: box (required), key (required), ack, limit.
Delivers a message to an agent mailbox by id: body up to 16 KB plus optional sender name and reply_to address (for example the sender's own mailbox id). Returns the message id and delivery confirmation; 404 if the mailbox does not exist or has expired. A public demo mailbox (demo000000000000000000) is available for testing. Price: $0.001 USDC per call (x402).
Inputs: to (required), body (required), from, reply_to.
Formatted citation for any DOI registered with Crossref or DataCite (journal articles, books, arXiv preprints, datasets): BibTeX entry plus a formatted reference in APA, MLA, Chicago author-date, IEEE, Harvard, Nature or AMA style. Resolves through DOI content negotiation with Crossref metadata as fallback. Price: $0.002 USDC per call (x402).
Inputs: doi (required), style.
Full-text search across 250M+ scholarly works in OpenAlex: title, authors, year, venue, type, citation count, open-access status with PDF link, reconstructed abstract (up to 1500 chars) and topics. Filters by publication date range and open access; sorted by relevance or citations. Returns the total match count and up to 25 papers per call with their OpenAlex IDs and DOIs. Price: $0.005 USDC per call (x402).
Inputs: q (required), sort, limit, since, +2 more.
One Polymarket market by numeric id or slug: question, resolution description, outcomes with current prices, Yes probability, last trade, best bid and ask, 24h price change, total and 24h volume, liquidity, end date, status, parent event, tags and the Polymarket URL. Source: Polymarket Gamma API. Price: $0.003 USDC per call (x402).
Inputs: id (required).
Polymarket prediction markets matching a text query, or the top markets by 24-hour volume when no query is given. Each market includes the question, every outcome with its current price (implied probability), the Yes probability, total and 24h volume, liquidity, end date, status and the Polymarket URL. Source: Polymarket Gamma API. Price: $0.005 USDC per call (x402).
Inputs: q, limit, active.
Validates a Mexican RFC (tax ID): structure, person type (física/moral), embedded date and SAT check digit. Offline, no SAT call. Price: $0.002 USDC per call (x402).
Inputs: rfc (required).
Mexican minimum wage set by CONASAMI: general daily rate and the Northern Border Free Zone rate for a given year, with monthly equivalents. Price: $0.001 USDC per call (x402).
Inputs: anio.
Checks an RFC against the SAT 69-B list of taxpayers with presumed non-existent operations (EFOS). Returns status (presunto, desvirtuado, definitivo, sentencia favorable), notice numbers and publication dates. Price: $0.02 USDC per call (x402).
Inputs: rfc (required).
Verifies a CFDI 3.3/4.0 invoice against the SAT web service: whether it exists, is vigente or cancelado, its cancellation status and EFOS flag. Needs UUID, issuer RFC, receiver RFC, total and the last 8 characters of the seal. Price: $0.03 USDC per call (x402).
Inputs: fe (required), id (required), re (required), rr (required), +1 more.
Reported financial values of a US-listed company from SEC XBRL company facts: the most recent annual (10-K) and quarterly (10-Q) figures for one concept such as revenue, net income, diluted EPS, total assets, cash or shares outstanding, with fiscal year, period dates, unit, form and filing date. Accepts friendly aliases or any us-gaap/dei concept name. Source: SEC EDGAR. Price: $0.005 USDC per call (x402).
Inputs: cik, limit, ticker, concept.
SEC EDGAR filings for a US-listed company by ticker or CIK, newest first, optionally filtered by form type (10-K, 10-Q, 8-K, 4, S-1...). Returns company name, CIK, SIC code and industry, state and fiscal year end, and for each filing the form, filing date, period, accession number, primary document and its EDGAR URL. Source: SEC submissions feed. Price: $0.005 USDC per call (x402).
Inputs: cik, form, limit, ticker.
Token verdict for a Base contract or Solana mint: DEX market data (price, liquidity, 24h volume, buys/sells, pair age), security checks (honeypot, taxes, mint/owner powers, holder concentration via GoPlus; RugCheck risks and LP lock on Solana), red and green flags, a one-word verdict and a plain-language take. Entertainment, not trading advice. Price: $0.02 USDC per call (x402).
Inputs: address (required), chain.
Current and historical UMA (Unidad de Medida y Actualización) values published by INEGI: daily, monthly and annual amounts with their effective dates. Price: $0.001 USDC per call (x402).
Inputs: anio.
Read any public web page as clean, LLM-ready markdown: title, meta description, language and main content with navigation, ads and scripts removed. Follows redirects. Cheapest way to read a URL before deciding whether to pay for a full render. Price: $0.001 USDC per call (x402).
Inputs: url (required), max_chars.
Every HTML table on a public web page as structured JSON: title (caption or nearest heading), headers, rows as arrays and as records keyed by header, numeric columns detected and parsed to numbers, colspan and rowspan expanded, footnote markers removed. Selecting one table by index also returns it as CSV. Row count capped by max_rows. Price: $0.003 USDC per call (x402).
Inputs: url (required), index, max_rows.
Which x402 API should I call for this task? Searches the Coinbase Bazaar catalog and ranks candidates by evidence of real use: distinct payers, repeat calls per payer, recency of payments and price. Returns up to 10 endpoints with URL, price, networks, example input and the reasons for the ranking. Price: $0.01 USDC per call (x402).
Inputs: need (required), limit, network, max_price.
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