x402 paid APIs: MCP servers, A2A agents and x402 APIs

• phone.openverbs.com Live x402

  Parse, validate and format a phone number — E.164/national/international/RFC 3966, region and line type (syntactic validation, no carrier lookup).

  x402 paid API · 1 endpoint

• physics.openverbs.com Live x402

  List every physical constant in the dataset, or only those in a given category (universal, adopted, electromagnetic, atomic, physico-chemical). Returns the constants, the total count and the set of available categories.…

  x402 paid API · 3 endpoints

• pixels.gateway.clawca.sh Live x402

  Inspect a public HTTPS URL for redirects, metadata, content type, word count, and content hash.

  x402 paid API · 1 endpoint

• places.openverbs.com Live x402

  Search Google's local business directory within a radius of a coordinate, filtered by category and/or a name query. Returns ranked businesses with name, category, star rating and review count, address, phone, website do…

  x402 paid API · 2 endpoints

• places.use.x402atlas.com Live x402

  Google Maps local business search — find places by query and map location (coordinates viewport), returning ratings, reviews, address, phone, website, hours & service options as clean JSON. (6 paid endpoints on places.u…

  x402 paid API · 6 endpoints

• poketpoker.com Live x402

  Deal one hand of Texas Hold'em against PoketPoker's bots and find out how your play compares. Five difficulty tiers; the top tier plays range-aware expected-value poker and beats every tier below it. Returns the table a…

  x402 paid API · 5 endpoints

• polymarket-signal-api.pwnker-polymarket-signals.workers.dev Live x402

  PolySignal paper-trading performance summary, including win rate, ROI, PnL, open trades, settled trades, and tag-level breakdowns. (2 paid endpoints on polymarket-signal-api.pwnker-polymarket-signals.workers.dev.)

  x402 paid API · 2 endpoints

• polymarketeer.vercel.app Live x402

  Get detailed information for a specific Kalshi event by ticker symbol

  x402 paid API · 1 endpoint

• polynews.news Live x402

  Real-time trade stream with market summaries (2hr rolling window, $500+ trades) (3 paid endpoints on polynews.news.)

  x402 paid API · 3 endpoints

• poolproof.ru Live x402

  Yield pool safety: peg of every underlying asset, yield sustainability, emission dependence, exit depth (9 paid endpoints on poolproof.ru.)

  x402 paid API · 9 endpoints

• port-scanner.underscoredone.com Live x402

  Give this API a hostname or IP address and it tries connecting to each port in your requested range. For every port that answers it reports whether it is open or blocked, which service is likely running there (a web ser…

  x402 paid API · 1 endpoint

• postal.openverbs.com Live x402

  List every ISO 3166-1 alpha-2 country code for which a postal-code pattern is available. (4 paid endpoints on postal.openverbs.com.)

  x402 paid API · 4 endpoints

• postcode-api-production.up.railway.app Live x402

  Look up a UK postcode: coordinates, country, region, council, ward, parish, parliamentary constituency, and ONS/NHS area codes. (5 paid endpoints on postcode-api-production.up.railway.app.)

  x402 paid API · 5 endpoints

• posttosource.com Live x402

  Convert a Twitter/X, LinkedIn, Medium, Substack, Beehiiv, or public Notion page URL into clean markdown.

  x402 paid API · 1 endpoint

• ppu43fkyhimq5fiqpmo42eh5ri0yypid.lambda-url.us-east-1.on.aws Live x402

  Email validation API. Checks whether a string is a syntactically valid email address using the same production-grade validation library trusted across the Node.js ecosystem, catching edge cases a quick regex misses. Ret…

  x402 paid API · 12 endpoints

• predictionmarketdata.io Live x402

  Recent news relevant to prediction markets within a publish-date window. (8 paid endpoints on api.predictionmarketdata.io.)

  x402 paid API · 8 endpoints

• preflight.openverbs.com Live x402

  Fetch any URL and, without paying, decode its x402 402 Payment Required challenge: price (atomic and formatted for known stablecoins), asset, network, payTo, resource, description, timeout and any input schema. Flags MP…

  x402 paid API · 1 endpoint

• premiumpin.com Live x402

  PremiumPin closed-catalog property search (3 paid endpoints on api.premiumpin.com.)

  x402 paid API · 3 endpoints

• preppers-paradise.com Live x402

  Paid book chapter (x402): Automate the Boring Stuff with Python: What Is Programming. Unit of a larger practical-skills library; free catalog at /library/discovery.json. Book slug: automatetheboringstuffwithpythonnew. R…

  x402 paid API · 1 endpoint

• prereason.com Live x402

  What changed since your last read: one page of PreReason's change events after a cursor. A briefing's state label, a tracked release, and, for the companies you name (?companies=, at most 200), newer figures, a situatio…

  x402 paid API · 12 endpoints

• problocks.io Live x402

  Verify payment connectivity with USDC on Base. Returns a JSON pong and UTC timestamp after settlement.

  x402 paid API · 1 endpoint

• products.openverbs.com Live x402

  Amazon product search API - search Amazon products / find products on Amazon by keyword (US). Live Amazon product data: ranked listings with ASIN, title, product URL, image, price range, currency, star rating, review co…

  x402 paid API · 4 endpoints

• professorsausages.com Live x402

  Newest headlines from a deduped, tiered 972-feed direct portfolio (primary sources + wires/majors + trade press + Hacker News + gated GDELT), newest first, up to 100 per call — filter by category, source, and language;…

  x402 paid API · 12 endpoints

• proof.platoskallipolis.com Live x402

  Before an AI agent trusts or pays a public API, inspect its public machine-readable evidence and x402 readiness. Submit a public HTTPS domain to check its agent card, OpenAPI, robots policy, and settlement-aware x402 si…

  x402 paid API · 1 endpoint

• property-risk-passport-api.lifebite-app.workers.dev Live x402

  Evaluate a US property address for parcel match, FEMA flood zone, flood proximity, taxing entities, school district, permit history, zoning/land-use context, insurance red flags, due-diligence risk score, quality score,…

  x402 paid API · 1 endpoint

• property.payapi.market Live x402

  UK street-level crime statistics by postcode (Police UK). (8 paid endpoints on property.payapi.market.)

  x402 paid API · 8 endpoints

• proxy.0000402.xyz Live x402

  Pay $0.01 USDC to make an outbound HTTP request through the proxy. Supports all standard HTTP methods, custom headers (including auth), and JSON or raw bodies. Responses are returned as text or base64-encoded binary. Ma…

  x402 paid API · 1 endpoint

• pulse.chainverdict.xyz Live x402

  API uptime and reliability monitoring for any x402 endpoint: a live quality verdict covering availability, uptime, latency percentiles, 402-offer conformance, price-drift and payTo-stability flags. Deterministic and re-…

  x402 paid API · 5 endpoints

• puptra-pdf-snapshot.saastemly.com Live x402

  The page's rendered content as Markdown. (5 paid endpoints on puptra-pdf-snapshot.saastemly.com.)

  x402 paid API · 5 endpoints

• q402.quackai.ai Live x402

  Paid API that reads a full DAO proposal and returns a structured voting recommendation with reasons.

  x402 paid API · 1 endpoint

• qist.info Live x402

  Convert Gregorian dates to Hijri (Umm al-Qura calendar) and back. Returns day/month/year, Arabic and English month names, and a formatted Arabic date string. Essential for agents handling Islamic events, Ramadan, Hajj s…

  x402 paid API · 2 endpoints

• qonoro.ai Live x402

  Validates email deliverability: syntax check, MX record lookup, and SMTP server reachability. Returns risk score and quality rating. Deterministic, sub-second. x402-native. (5 paid endpoints on api.qonoro.ai.)

  x402 paid API · 5 endpoints

• qr-api-production-1836.up.railway.app Live x402

  Generate a QR code PNG (returned base64-encoded in JSON) for any text or URL using default black-on-white styling. (4 paid endpoints on qr-api-production-1836.up.railway.app.)

  x402 paid API · 4 endpoints

• qr-code-generator.underscoredone.com Live x402

  Send a list of texts — website addresses, phone numbers, plain words, WiFi details, anything — and get back a ready-to-use QR code image for each one. Every QR code comes as a base64-encoded PNG you can drop straight in…

  x402 paid API · 1 endpoint

• qr.openverbs.com Live x402

  Render text (URL, vCard, Wi-Fi config, …) as a QR code — SVG string or PNG data URL. (3 paid endpoints on qr.openverbs.com.)

  x402 paid API · 3 endpoints

• qr.reyn.tools Live x402

  Generate scannable QR codes from any text, URL, or structured payload (WiFi, vCard, SMS, email, geo, crypto). Returns PNG by default with JPG, WebP, and SVG output, plus optional error-correction, sizing, color, version…

  x402 paid API · 1 endpoint

• quantum.halowerk.com Live x402

  Interpolates a caller-supplied start and end temperature across a bounded number of steps using either a linear or geometric rule. It does not run an annealer, optimize a problem Hamiltonian or tune a schedule from hard…

  x402 paid API · 10 endpoints

• quokkapix.com Live x402

  QuokkaPix image agent unlock for image-standard. Media stays local on the user's device.

  x402 paid API · 1 endpoint

• quotient-api-gateway.onrender.com Live x402

  Use this to read published Quotient signals. Sports signals return one game-level pick and markets[] with every linked venue listing, its signal_side, price, and availability. No venue is primary or preferred. Missing q…

  x402 paid API · 12 endpoints

• randomfactsx402.vercel.app Live x402

  Returns a single random fact as JSON in exchange for a micropayment.

  x402 paid API · 1 endpoint

• random.openverbs.com Live x402

  Generate cryptographically-secure random bytes, returned as hex, base64 or base64url. (4 paid endpoints on random.openverbs.com.)

  x402 paid API · 4 endpoints

• rates.lonestaroracle.xyz Live x402

  US bond-market signal: yield curve, credit spreads, real yields (no params)

  x402 paid API · 1 endpoint

• ravn.exchange Live x402

  RAVN — best-price swap quotes across 20 execution venues and 17 chains, including native (non-wrapped) Bitcoin as either source or destination. 0% protocol fee, non-custodial. Returns a quoteToken; pass it to POST /exec…

  x402 paid API · 2 endpoints

• readability.openverbs.com Live x402

  Summarise a text's difficulty as a single consensus US grade level (averaging the five grade formulas), plus the Flesch Reading Ease, a plain-language difficulty band and an approximate age range. (4 paid endpoints on r…

  x402 paid API · 4 endpoints

• read.lonestaroracle.xyz Live x402

  Clean web content extraction — any URL to markdown + text + metadata

  x402 paid API · 1 endpoint

• readx.sh Live x402

  Search for tweets by query (optional product filter; paginate with cursor). Example: GET /api/search/tweets?q=typescript (12 paid endpoints on readx.sh.)

  x402 paid API · 12 endpoints

• realestate.lonestaroracle.xyz Live x402

  US real estate and mortgage — 30yr/15yr fixed rates, ARM, housing starts, permits, Case-Shiller HPI

  x402 paid API · 1 endpoint

• recalls.recordsforagents.com Live x402

  Search US federal product recalls (CPSC consumer products, FDA food/drug/device enforcement, USDA FSIS meat/poultry recalls, NHTSA vehicle campaigns) by free-text query, firm name, date range, and source. (2 paid endpoi…

  x402 paid API · 2 endpoints

Related capabilities

On-chain dataTrading & marketsAI models & inferenceAgent infrastructureMaps & travelResearchSecurity & trustCrypto market data

How to use one

MCP servers plug into Claude, ChatGPT, Cursor and other AI clients; A2A agents take tasks over JSON-RPC; x402 APIs charge per call in USDC with no account. Guides: A2A vs MCP · How to call an A2A agent · x402 for agents.

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