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

• scrooge-x402-tool-mill.vercel.app Live x402

  Extract schema.org structured data from a public HTML page: JSON-LD (@graph flattened), top-level microdata, and Open Graph / Twitter meta. Normalizes Product/Offer, Article, Organization, Event, FAQ, and breadcrumbs. P…

  x402 paid API · 8 endpoints

• scvd.store Live x402

  Spot Check. REQUIRES ?host= on the paid request — a signed request without it is refused before the gate and no money moves. Name a host and get what this observatory already holds on it, signed: corpus rounds and verdi…

  x402 paid API · 12 endpoints

• search.cyberwarex.com Live x402

  Web search that returns structured SERP results as JSON. Runs on a dedicated SearXNG instance aggregating multiple engines, so there is no per-engine API key, quota or HTML scraping to manage. Each result carries title,…

  x402 paid API · 5 endpoints

• search.openverbs.com Live x402

  Wikipedia summary API - the plain-language summary of the best-matching Wikipedia article for a topic or query, in any language. Returns the article title, short description, summary extract, thumbnail image and canonic…

  x402 paid API · 10 endpoints

• sec.use.x402atlas.com Live x402

  SEC company financials by ticker — normalized annual and quarterly revenue, income, balance-sheet, cash-flow and EPS facts. (3 paid endpoints on sec.use.x402atlas.com.)

  x402 paid API · 3 endpoints

• seerium.xyz Live x402

  Macro market signals API for agents. Tracks inflation, rates, liquidity, economic releases, crypto, and prediction markets. (26 paid endpoints on api.seerium.xyz.)

  x402 paid API · 12 endpoints

• semver.openverbs.com Live x402

  Parse a semantic version into major/minor/patch, prerelease and build metadata. (3 paid endpoints on semver.openverbs.com.)

  x402 paid API · 3 endpoints

• sentiment.openverbs.com Live x402

  Market & brand sentiment for any keyword, brand, ticker or product: analyses the sentiment of web & news content mentioning it and returns an overall label (positive/negative/neutral/mixed), a net sentiment score (-1..1…

  x402 paid API · 1 endpoint

• sentinel.rootstuff.io Live x402

  Every DNS record for a domain plus propagation across public resolvers (7 paid endpoints on sentinel.rootstuff.io.)

  x402 paid API · 7 endpoints

• seo-data-extractor.underscoredone.com Live x402

  Give this API a web address and it will visit that page, then hand back everything an SEO professional needs to know: the page title, meta description, meta keywords, robots instructions, canonical link, H1/H2/H3 headin…

  x402 paid API · 1 endpoint

• seo.forgemesh.io Live x402

  Correct likely spelling errors in an SEO query (2 paid endpoints on seo.forgemesh.io.)

  x402 paid API · 2 endpoints

• seo.halowerk.com Live x402

  Title present audit fetches current public evidence from the supplied target and evaluates the documented criterion. It returns the observation, threshold, verdict, exact evidence source, limitations and a mode-specific…

  x402 paid API · 5 endpoints

• seo.openverbs.com Live x402

  Domain overview: estimate a domain's Google SEO footprint — total organic and paid keywords, estimated traffic (ETV), traffic cost, and how many keywords rank in the top 3, top 10 and top 100. Fast website and domain SE…

  x402 paid API · 12 endpoints

• seoul-weather-402.fly.dev Live x402

  Real-time Seoul weather — temperature, sky, humidity, wind (KMA official data)

  x402 paid API · 1 endpoint

• serp402.com Live x402

  Google search for agents, paid per call: web, news, images, videos, places, shopping and Scholar, all returned in one shape with canonicalised URLs, duplicates removed and dates normalised to ISO. Direct answers and kno…

  x402 paid API · 1 endpoint

• settled.tools Live x402

  Signed check of an x402 endpoint before you pay it: who really pays it on Base (settlements and unique payers over 30 days), a fresh unpaid probe (cached ≤5 min) with status, latency and the parsed quote, payability, pa…

  x402 paid API · 8 endpoints

• sftunes.com Live x402

  SFtunes catalog for agents: index of public mixtapes and public Top 10 lists, or one item with liner notes and music-service links via ?id=<uuid> (tape) or ?id=top10-<handle> (a person's Top 10 + Side B).

  x402 paid API · 1 endpoint

• sg-cm-kg.ai Live x402

  One paid call on sg-cm-kg.ai for $0.01 USDC: the surface's own statement of record (a market node: its list_nodes line; a product: its record of record; allooloo.io: the estate scale block), public-record only, with an…

  x402 paid API · 1 endpoint

• sh-origin.walls.sh Live x402

  Real-time news search for AI agents. Returns recent news articles (title, link, snippet, published date) as JSON from a multi-engine news metasearch. Pay-per-query in USDC via x402 — no signup, no API key. Use for curre…

  x402 paid API · 4 endpoints

• shared-hold-api.onrender.com Live x402

  Store payload to Shared Hold boundary - 0.005 USDC per successful hold

  x402 paid API · 1 endpoint

• shield.vainplex.dev Live x402

  ShieldAPI - x402 security preflight before agents accept or store credential material (3 paid endpoints on shield.vainplex.dev.)

  x402 paid API · 3 endpoints

• shizu.me Live x402

  Fetch any public web page and return its main content as clean Markdown, ready to feed to an LLM. Boilerplate (nav, ads, footers) stripped. Input: url (public http/https). Returns {url, markdown, word_count}. (30 paid e…

  x402 paid API · 12 endpoints

• shopify-ai-rank-checker.underscoredone.com Live x402

  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. Search…

  x402 paid API · 1 endpoint

• shop.netlobo.com Live x402

  Live crypto prices: USD spot for BTC, ETH and SOL in one call, fetched per call (not cached), so the figure is the number right now. A cheap, high-frequency data lane for x402 buyers budgeting in the unit they pay with.…

  x402 paid API · 12 endpoints

• shot.halowerk.com Live x402

  Viewport or full page, optional element selector, dark mode and cookie banner removal. Returns base64 image plus a short lived fetch URL, byte size, load time and the final HTTP status of the page.

  x402 paid API · 1 endpoint

• sicher.halowerk.com Live x402

  Providers each build their signing string differently — some sign only the body, others prepend a timestamp, an id, or a version marker in a fixed order — and getting that order wrong produces a mismatch that looks exac…

  x402 paid API · 4 endpoints

• signal-engine-production-d88d.up.railway.app Live x402

  Individual arena strategy signal (10 paid endpoints on signal-engine-production-d88d.up.railway.app.)

  x402 paid API · 10 endpoints

• signalfuse.co Live x402

  Macro regime classification (risk-on/risk-off/neutral) (38 paid endpoints on api.signalfuse.co.)

  x402 paid API · 12 endpoints

• signalis.dev Live x402

  Paid ($0.01 USDC via x402). Active AI-business narratives with lifecycle stage, driving sources, and momentum. Proxied from the Pulse service. Compute-first / settle-after — you are never charged when Pulse is unavailab…

  x402 paid API · 2 endpoints

• signals.nsgoods.org Live x402

  Live market-state data for one crypto pair: BUY/SELL/HOLD state + confidence from a multi-timeframe engine. Machine-readable, ECDSA-signed. Input data for AI finance agents (USDC pay-per-call). Free preview: GET /signal…

  x402 paid API · 6 endpoints

• sign.cyberwarex.com Live x402

  Decode an off-chain SIGNATURE REQUEST before you sign it: EIP-712 typed data (eth_signTypedData_v4) or a plain personal_sign string. Turns the opaque request into a human-readable summary plus security risk flags for th…

  x402 paid API · 1 endpoint

• sirenic.eu Live x402

  French company search and company lookup by name or SIREN in the official French company registry (INSEE Sirene / INPI RNE open data). Name search returns the top 10 matches with identity, SIREN, NAF code, city and acti…

  x402 paid API · 12 endpoints

• sitemap-url-extractor.underscoredone.com Live x402

  Give this API a link to any website's sitemap.xml file and it will fetch and parse it, returning every URL found inside. If the sitemap links to other sitemaps (called sitemap indexes), it will follow and extract those…

  x402 paid API · 1 endpoint

• skim402.com Live x402

  Skim Signal: film incentives — new state film-incentive award rounds and allocations across California, New York, Georgia, New Mexico, and Texas as structured items: official California Film Commission and Texas Governo…

  x402 paid API · 10 endpoints

• slug.openverbs.com Live x402

  Convert text into a URL-safe slug: transliterate accents, apply a locale character map, and join with a separator.

  x402 paid API · 1 endpoint

• smartmoney.market Live x402

  Global US House Periodic Transaction Report activity for stock-backed trades. Supports overview, latest disclosures, focused buys/sells, active tickers, active members, days, view, and limit. (3 paid endpoints on x402.s…

  x402 paid API · 3 endpoints

• socialfetch.dev Live x402

  Search public LinkedIn posts site-wide by keyword (not scoped to one profile or company — use linkedin.profiles.posts.list or linkedin.company.posts.list for that). (39 paid endpoints on api.socialfetch.dev.)

  x402 paid API · 12 endpoints

• solar.halowerk.com Live x402

  Uses rated electrical power, food mass, start and target temperature, specific heat and an explicit efficiency range supplied by the caller. Optional vessel heat, evaporation and a caller-defined hold phase can be inclu…

  x402 paid API · 4 endpoints

• solar.nsgoods.org Live x402

  Signed plug-in solar legality record for one US state. Free preview: GET /solar-legality/preview A missing or unknown state returns 400 or 404; you are never charged for an error. (2 paid endpoints on solar.nsgoods.org.)

  x402 paid API · 2 endpoints

• solgiery.com Live x402

  Generate 1 to 1000 uniformly distributed random integers between min and max, inclusive. Both bounds are required; min must not exceed max. Repeated values are possible. Uses the server OS CSPRNG. Returns consumed bytes…

  x402 paid API · 11 endpoints

• sovereign-x402-zeta.vercel.app Live x402

  Scrape a URL and return clean Markdown (via Firecrawl). Priced above Firecrawl's own per-scrape cost. (9 paid endpoints on sovereign-x402-zeta.vercel.app.)

  x402 paid API · 9 endpoints

• sovereign.lonestaroracle.xyz Live x402

  Per-country sovereign economic / default-risk score (?country=<name or ISO3>)

  x402 paid API · 1 endpoint

• space-weather.use.x402atlas.com Live x402

  Current space-weather conditions — normalized NOAA SWPC Kp, solar wind, magnetic field, and X-ray flux used for solar-flare monitoring, with observation times and freshness. (3 paid endpoints on space-weather.use.x402at…

  x402 paid API · 3 endpoints

• space.halowerk.com Live x402

  Computes mean NDVI and an ordinary least-squares daily NDVI trend, then applies yield = intercept + mean_coefficient×mean_NDVI + trend_coefficient×daily_trend. It does not derive NDVI from imagery, account for crop stag…

  x402 paid API · 10 endpoints

• spark.lonestaroracle.xyz Live x402

  Wholesale US electricity-market price + volatility signal (no params)

  x402 paid API · 1 endpoint

• speccy.cloud Live x402

  Top Polymarket prediction markets by 24h volume. Returns up to 50 markets with id, question, slug, volume, volume24hr, liquidity, endDate, outcomes and outcomePrices. (2 paid endpoints on api.speccy.cloud.)

  x402 paid API · 2 endpoints

• speedbot.dev Live x402

  Public sources for agent research: one Brave search plus fetch of up to three public HTTPS pages. Returns structured JSON with page text, metadata, source URLs, fetch timestamps and content hashes for source checking an…

  x402 paid API · 1 endpoint

• spendthebits.com Live x402

  Official $0.01 proof-of-life resource for SpendTheBits x402: returns a JSON heartbeat. Pay it to verify your agent's x402 client end to end. (7 paid endpoints on x402.spendthebits.com.)

  x402 paid API · 7 endpoints

Related capabilities

On-chain dataTrading & marketsAI models & inferenceMaps & travelResearchAgent infrastructureSecurity & 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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