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Every pay-per-call x402 API we can find, ranked by what agents actually pay for. No accounts, no API keys.
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555 results- DDomain Availability CheckerSearch & web
Give this API up to 10 domain names and it tells you whether each has a registration record at the official registry. It uses RDAP, the structured replacement for WHOIS, so there is no free-text parsing. Each domain comes back as 'registered', 'unregistered', or 'indeterminate' when the registry has no RDAP for that ending. 'Unregistered' means no record was found, which usually means available -
BaseSolanadomain-availability-checker.underscoredone.comfrom $0.011 endpoint - DDomain Age CheckerDeveloper tools
Send a list of domain names and this tool tells you exactly how old each one is, when it was first registered, when it expires, and how much time is left before expiration. Great for spotting brand-new suspicious domains, researching competitors, or evaluating domains before buying or linking to them. Works with over 100 domain extensions worldwide.
BaseSolanadomain-age-checker.underscoredone.comfrom $0.012 endpoints - BBulk DMARC Record LookupDeveloper tools
Give this tool a list of domain names and it will instantly check each one's DMARC email security record. DMARC is a standard that tells email providers how to handle fake or spoofed emails pretending to come from your domain. For each domain you submit, you get back whether a valid record exists, what the policy is (none, quarantine, or reject), whether reporting addresses are set up, and the ful
BaseSolanadmarc-lookup.underscoredone.comfrom $0.011 endpoint - AAI Data ToolsSearch & web
Data Quality Gate: deterministic dataset quality verdict
SolanaBaseaidatatools.devfrom $0.011 endpoint - Xx402-stall-l3bb.onrender.comOther services
Hello from Taiwan — a signed timestamp from my first x402 stall
BaseSolanax402-stall-l3bb.onrender.comfrom $0.011 endpoint - Ssocialintel.devSocial & people
No description yet.
BaseSolanaPolygon+1socialintel.devfrom $0.011 endpoint - GGiftPulseSearch & web
Search Reloadly's gift card catalog (300+ brands, 14,000+ products/denominations across countries). Returns each product's id, brand, country, denomination range or fixed amounts, and sender fee/discount — everything needed to build a POST /api/giftcard/quote call.
BaseSolanaPolygon+8giftpulse.theaslangroupllc.comfrom $0.011 endpoint - Ffiles.camelai.ioDeveloper tools
Upload a file and get a temporary signed URL. Send raw file body with Content-Type header. Returns a URL valid for 1 hour.
BasePolygonSolanafiles.camelai.iofrom $0.0011 endpoint - UURL Uptime CheckerData & research
Checks whether a website or web address is currently reachable and reports how fast it responded.
BaseSolanaurl-uptime-checker.underscoredone.comfrom $0.011 endpoint - CCanadian Rates and YieldsMarkets & finance
Compare Canadian interest rates and government bond yields using the latest available Bank of Canada policy rate and six benchmark maturities. Track monetary policy, benchmark borrowing costs and compare the yield curve. Original data is available free at bankofcanada.ca.
BasePolygonArbitrum+1canada-rates.use.x402atlas.comfrom $0.011 endpoint - GGlobal Legal EntitiesSocial & people
Company name search — find Legal Entity Identifiers (LEIs), legal names, jurisdictions and registration status. Get up to ten matches per page to identify counterparties, distinguish similarly named companies and enrich company reference data.
BasePolygonArbitrum+1legal-entities.use.x402atlas.comfrom $0.011 endpoint - SShopify AI Rank CheckerSearch & web
Checks how well a Shopify store's products show up when AI shopping assistants such as ChatGPT, Gemini, Perplexity, Grok, and Copilot search for products, and reports the store's rank and its closest competitors. Searches Shopify's real Global Catalog - the same product index AI assistants read from.
BaseSolanashopify-ai-rank-checker.underscoredone.comfrom $0.011 endpoint - PPolymarket EventsCrypto & DeFi
Prediction market events by topic — page through open or closed Polymarket events under one tag such as politics, crypto, economy, geopolitics or ai, each with status, dates, volume, liquidity and markets with current YES prices. Use to survey what a prediction market is pricing on a subject.
BasePolygonArbitrum+1polymarket.use.x402atlas.comfrom $0.012 endpoints - MMailPulseImages, audio & video
Check the status and tracking of a physical letter previously sent via POST /api/letters. Returns render status, expected delivery date, and (for certified mail) the USPS tracking number.
BaseSolanaPolygon+8mailpulse.theaslangroupllc.comfrom $0.0052 endpoints - Mmailcheck.hugen.tokyoCrypto & DeFi
MX record lookup for any domain — returns whether mail servers exist and their hostnames sorted by priority. Verify email deliverability before sending. Supports all TLDs including ccTLDs and new gTLDs. No DNS library setup needed. Accepts USDC payments on Base and Solana
BaseSolanamailcheck.hugen.tokyofrom $0.013 endpoints - Ffoi.itsthesheet.caSearch & web
Full-text search of published British Columbia FOI release packages.
BaseSolanafoi.itsthesheet.cafrom $0.011 endpoint - DDNS & WHOIS LookupSocial & people
Send up to 10 domain names and get back every DNS record type (A, AAAA, MX, CNAME, TXT, NS, PTR, SOA, SRV, CAA, NAPTR, DS, TLSA) plus the full WHOIS registration profile (registrar, dates, contacts, status, nameservers) for each one. URLs are accepted and automatically stripped down to the bare domain. Duplicate domains are quietly removed before processing. Results come back as one flat row per d
BaseSolanadns-whois-lookup.underscoredone.comfrom $0.011 endpoint - CCurl HTTP RequestCrypto & DeFi
Send an HTTP request to any URL from our servers and receive the full response — including the status code, all response headers, and the body content. Supports GET, POST, PUT, PATCH, DELETE, and HEAD. Automatically follows up to 3 redirects. Useful for testing endpoints, verifying servers are responding correctly, debugging redirect chains, or fetching raw data without needing a local setup.
BaseSolanacurl-http-request.underscoredone.comfrom $0.011 endpoint - Xx402 Launch KitOther services
Returns a Markdown launch kit and seven-day checklist for an x402 service.
BaseSolanacrowdcode.appfrom $0.0031 endpoint
CodePulseOther servicesPackage security scanner — CVEs, license check, typosquat detection.
BaseSolanacodepulse.waltsoft.netfrom $0.0051 endpoint- Aarn-x402-payguard-payment-security.rajdeep-dutta-in.workers.devAI & agents
Agent Reliability Network: ARN x402 PayGuard provides x402 payment security for autonomous AI agents. Check the seller before you pay with payment preflight and payment-challenge validation. Returns ALLOW, CAUTION, or BLOCK.
BaseSolanaarn-x402-payguard-payment-security.rajdeep-dutta-in.workers.devfrom $0.0011 endpoint - Aapi.xona-agent.comImages, audio & video
ElevenLabs text-to-speech: convert text to speech (MP3) (Base Mainnet).
SolanaArbitrumEVM chain 1187947933+1api.xona-agent.comfrom $0.001420 endpoints - GadgetHumans APISocial & people
Is this Base token safe to buy, or a honeypot, rug pull or scam? Send a Base (chainID 8453) ERC-20 contract address and get a pre-trade safety verdict before you swap, snipe, route or approve it: honeypot simulation (can you actually sell it?), buy tax and sell tax, mint and owner privileges, blacklist and pause functions, verified source, holder concentration, live liquidity and 24h volume, plus
BaseSolanaapi.gadgethumans.comfrom $0.001204 endpoints - CChat Completion (basic)Crypto & DeFi
LLM completion per call, no account and no API key: POST a prompt (or a messages array) and get the model answer as JSON. Hard caps disclosed in every response (6,000 UTF-8 bytes in, 750 tokens out on this tier). Fixed price per call, signed receipt included so the answer stays auditable. Larger tier at /x402/chat-plus.
BaseArbitrumPolygon+1api.eucompliance.toolsfrom $0.00123 endpoints - Aagent.agentflare.orgAI & agents
No description yet.
BaseSolanaagent.agentflare.orgfrom $0.0053 endpoints - WWikidata Entity SearchSocial & people
Wikidata entity search — find the Wikidata item for a person, organisation, place, work or concept by name or alias, in any language, with id, label, description and which term matched; or find a property by name. Use to get the Q-id before asking for an entity's facts, identifiers or links.
BasePolygonArbitrum+1wikidata.use.x402atlas.comfrom $0.011 endpoint - VVeridictum LegalAI & agents
Verify one legal citation. Body: {"citation": "<string>"} - full ("Miranda v. Arizona, 384 U.S. 436 (1966)") or bare ("384 U.S. 436"); the case name enables mismatch detection. Deterministic: regex plus cache / local corpus / CourtListener, no LLM in the path. status=verified (name confirmed), suspicious (reporter resolves to a DIFFERENT case - the fabrication signature), or not_found. verified=fa
BaseSolanaveridictum.legalfrom $0.012 endpoints - SSato HubCrypto & DeFi
Daily Sato Score history for one Sato Hub listing: score, tier components, GitHub stars, status and verification state per day, with the dates the score moved (genuine changes vs our own method revisions marked). Captured daily since 2026-06-12; not reconstructable. The current catalog and the daily score line stay free. Priced per daily point returned: $0.005 for up to 90 days, +$0.001 per day be
BaseSolanasatohub.aifrom $0.0052 endpoints - IInfoharmoni Radar whoCrypto & DeFi
Is this x402 seller real? One seller's report card before you pay them: what they sell, price, rank of all sellers, rivals, and from the chain who actually pays it on Base: payer wallets, how concentrated they are, how many came back on 2 or more days, and how many of its payers are wide samplers that paid 30+ sellers (not shoppers). Dated, with the evidence behind each fact. $0.001 a call. Refusa
BaseSolanaausrine-who.onrender.comfrom $0.0011 endpoint - 110x402Other services
Run ONE named check against a response you paste
BaseSolana10x402.comfrom $0.0041 endpoint
Service data comes from the Coinbase CDP and PayAI discovery lists and refreshes every few hours. Usage is paid calls over the last 30 days. APIs launched here are verified by us; the rest are paid directly to their owners.