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

• browser.gedx402.com Live x402

  Firecrawl v2 API proxy — map. JSON body matches https://docs.firecrawl.dev/api-reference/v2-introduction. Poll GET routes are free; POST/PUT/DELETE are x402. $0.010 USDC per request. Agent search: site map, crawl map, f…

  x402 paid API · 2 endpoints

• btc-radar.vercel.app Live x402

  Bitcoin protocol and software changes as JSON: Bitcoin Core merges and releases, BIP updates, Lightning spec and implementation changes. Each item has status (proposal, merged, released, activated), layer (consensus, po…

  x402 paid API · 3 endpoints

• btcnode.uk Live x402

  Last N blocks (default 10): height, hash, size, txcount, time — flat $0.001 per call, USDC on Base, no signup. (10 paid endpoints on btcnode.uk.)

  x402 paid API · 10 endpoints

• buildscottsbluff.com Live x402

  American Community Survey 5-year demographics for Scotts Bluff County and each of its ten places, plus a 16-year trend series: population, median household and per-capita income, poverty, median home value, gross rent,…

  x402 paid API · 2 endpoints

• builtwith.com Live x402

  Return BuiltWith technology detections and metadata for one domain. Useful for company research, stack analysis, competitive intelligence, and sales qualification.

  x402 paid API · 1 endpoint

• bunnvault.xyz Live x402

  BunnVault: Real-time Aave v3 USDC APY feed on Base Mainnet

  x402 paid API · 1 endpoint

• burn-once-secret-vault.jannioura.workers.dev Live x402

  Store a secret (API key, webhook payload, signed URL) encrypted with WebCrypto AES-256-GCM and share a claim URL that yields the secret exactly once. A Durable Object serializes reads so single-use delivery is race-free…

  x402 paid API · 1 endpoint

• byfaro.ai Live x402

  Single-signal check: is this website's pricing machine-readable for AI agents? Detects Offer schema with price/availability and pricing-transparency signals. Returns yes/no plus underlying checks and fixes. Useful for p…

  x402 paid API · 2 endpoints

• canary.countersignpay.com Live x402

  Current Base mainnet block height and base fee per gas in wei, read from the chain at request time

  x402 paid API · 1 endpoint

• capitol.lonestaroracle.xyz Live x402

  US congressional (Senate+House) stock trades; ?symbol= for a ticker

  x402 paid API · 1 endpoint

• carbon-cashmere.de Live x402

  Recent Kaspa blocks (max 144 per call = $1.44 cap). Optional chain_only flag to filter selected-parent chain blocks. AI agent API for backtesters and indexers. Informational research data — not investment advice. (18 pa…

  x402 paid API · 12 endpoints

• cars2026.vercel.app Live x402

  Educational briefing on the latest cars in 2026 (powertrains, range, pricing, and what's new).

  x402 paid API · 1 endpoint

• carvector.io Live x402

  CarVector vehicle data — single API call

  x402 paid API · 1 endpoint

• Catalyst Desk Live A2A

  Live Polymarket / prediction-market intelligence for AI agents. Free /v1/pulse; paid /v1/movers and /v1/brief via x402 USDC on Base. Not financial advice. No custody.

  A2A agent · dinosolace · 3 skills

• cc0.company Live x402

  cc0.company — x402 agent-services marketplace on Base (USDC): CC0 image generation, market-data digests, and third-party agent tools. This endpoint: cc0pedia — look up any CC0 creator, collection, or work by name/slug a…

  x402 paid API · 6 endpoints

• cdp-agent-0-01.onrender.com Live x402

  AgentWire service card for webhook inbox relay and web fetch infrastructure.

  x402 paid API · 1 endpoint

• celerapi.com Live x402

  Search authoritative company registries by company name to resolve candidate legal entities and registration identifiers. Currently supports the United Kingdom (GB) and Norway (NO), with expanding jurisdiction coverage.…

  x402 paid API · 1 endpoint

• chain.cyberwarex.com Live x402

  ENS name resolution in both directions on Ethereum mainnet. Pass name to resolve an ENS name to its address (forward), or pass address to get that address's primary ENS name (reverse, forward-verified so spoofed reverse…

  x402 paid API · 7 endpoints

• chain.openverbs.com Live x402

  Live recommended Bitcoin transaction fee rates (in sat/vB) for next-block, ~30-minute, ~1-hour, economy and minimum confirmation targets, straight from the mempool. Also estimates the total fee (in sats and BTC) for a t…

  x402 paid API · 12 endpoints

• chainquery.com Live x402

  chainquery Bitcoin RPC: pay-per-call Bitcoin Core over x402, no API key. Currently banned peer IPs and subnets from chainquery's independent full node. Bitcoin Core listbanned. (3 paid endpoints on x402.chainquery.com.)

  x402 paid API · 3 endpoints

• chainscout.lonestaroracle.xyz Live x402

  On-chain intelligence — whale transfers trending tokens DeFi TVL on Base and Ethereum

  x402 paid API · 1 endpoint

• chainsscope.duckdns.org Live x402

  Current network fee conditions -- gas price (ETH/Base/Arbitrum/Optimism/Polygon), sat/vB fee tiers (Bitcoin), or recent prioritization fees (Solana) -- useful for an agent about to construct a transaction itself. (2 pai…

  x402 paid API · 2 endpoints

• chain.tollkit.dev Live x402

  Crypto token price in USD for AI agents: give a token contract address or mint (or "SOL") on Base, Ethereum or Solana, get its live USD price read on-chain from the deepest DEX pool (Uniswap v3, Orca Whirlpools), not fr…

  x402 paid API · 7 endpoints

• chainverdict.xyz Live x402

  Latest Base block: number, timestamp and hash. The cheapest call on the service — useful as a liveness and connectivity check. (22 paid endpoints on chainverdict.xyz.)

  x402 paid API · 12 endpoints

• charliemorrison.dev Live x402

  Web-content reader: fetch any http(s) URL and return clean readable text, title/description/canonical, and outbound links as JSON — the data an agent ingests on each step of a crawl or RAG loop. Input: url. (3 paid endp…

  x402 paid API · 3 endpoints

• chat.gedx402.com Live x402

  Multi-model chat completions. POST messages[] and set model to any LLM id from GET /v1/models; dynamic USDC pricing scales with model and token usage. Hero: GET /heroes/chat-completions.

  x402 paid API · 1 endpoint

• citepulse.theaslangroupllc.com Live x402

  Single-paper lookup by DOI or title for research agents — citation count, influence, open-access status with a direct legal-OA link (Unpaywall), venue, and a TLDR. Deterministic passthrough over OpenAlex + Semantic Scho…

  x402 paid API · 2 endpoints

• clashofcoins.com Live x402

  Low-cost gateway health probe for real x402 settlement checks

  x402 paid API · 1 endpoint

• clawinabox.xyz Live x402

  Spend-policy verdict for AI agents: POST a proposed spend, get allow/review/deny with the exact rules that fired (per-tx caps, per-agent daily ledger, destination allowlists, time windows) - 'review' can page a human on…

  x402 paid API · 1 endpoint

• clinicalintelpulse.theaslangroupllc.com Live x402

  ClinicalTrials.gov lookup, deterministic. Answers "what is the status of NCT02142738", "recruiting phase-3 melanoma trials", "Pfizer trial pipeline". Single trial by NCT id (status, phase, sponsor, enrollment, dates, co…

  x402 paid API · 1 endpoint

• clinic.sapthumbprint.com Live x402

  Mid-task, and nothing said to you will be kept? One line of encouragement, plus an id you can quote back to us later. Unsigned: nobody but us can check it, and only against our own record; /v1/keepsake signs it so anyon…

  x402 paid API · 2 endpoints

• clink-lithium-vault.fly.dev Live x402

  X/Twitter search for AI agents - live tweets via advanced search: from:user, exact phrases, #hashtags, min_faves, lang, since/until dates. Returns up to 20 newest matches with author, followers, likes, retweets, views,…

  x402 paid API · 12 endpoints

• clinkagent.com Live x402

  What do the prediction markets say? Pass a question, get a finished read an agent can use directly: the best-matching market on Polymarket and on Kalshi with implied probability and 24h/7d moves, the cross-platform gap…

  x402 paid API · 12 endpoints

• cm-kg.io Live x402

  One paid call on cm-kg.io 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 EdD…

  x402 paid API · 1 endpoint

• cm-record.org Live x402

  One paid call on cm-record.org 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 a…

  x402 paid API · 1 endpoint

• cn402.com Live x402

  Chinese temple fortune slip divination (求签, 签文, 抽签). Draws a numbered qianzi slip from traditional Chinese temple oracles (Guanyin 观音, Guan Di 关帝, Mazu 妈祖), returns slip number, level (上签, 中签, 下签), classical poem, and i…

  x402 paid API · 12 endpoints

• codepulse-api.hahavoid0.workers.dev Live x402

  Fetches TXT, MX, A, CNAME, and CAA records for a domain via Cloudflare DNS-over-HTTPS. (5 paid endpoints on codepulse-api.hahavoid0.workers.dev.)

  x402 paid API · 5 endpoints

• Coin Railz (travis-kellogg1) Live MCP

  63 x402 micropayment services via USDC — crypto analytics, trading signals, NASA/ESA satellite data, IoT sensors, AI inference, and prediction markets. Coinbase AgentKit compatible. Pay per call with prepaid credits or…

  MCP server · travis-kellogg1

• coinflip402.vercel.app Live x402

  Flip a coin for a small USDC payment on Base mainnet. Returns heads or tails.

  x402 paid API · 1 endpoint

• coingecko.use.x402atlas.com Live x402

  Crypto token price in USD, EUR and more — real-time spot prices for one or many coins by CoinGecko id (bitcoin, ethereum, solana). (6 paid endpoints on coingecko.use.x402atlas.com.)

  x402 paid API · 6 endpoints

• coinopai.com Live x402

  Returns the 4 top-level product categories (market intelligence, workflows, media generation, infrastructure) with endpoint lists and service counts — use it to route discovery before browsing individual services. (16 p…

  x402 paid API · 12 endpoints

• combinatorics.openverbs.com Live x402

  The n-th Catalan number Cₙ = C(2n, n)/(n+1), counting balanced bracketings, binary trees, and many other structures. Requires n ≤ 10000. (5 paid endpoints on combinatorics.openverbs.com.)

  x402 paid API · 5 endpoints

• companylens.ve1iko.chatgpt.site Live x402

  Resolve a UK legal company name or registration number to a sourced Companies House profile. Returns company status, incorporation, SIC codes, registered office, filing due dates and overdue flags. Use for company resea…

  x402 paid API · 1 endpoint

• compliancepulse.theaslangroupllc.com Live x402

  Is this EU VAT number valid? Live VIES check against the European Commission's official VAT Information Exchange System — validate a European VAT id, verify a business tax id before invoicing, confirm B2B reverse-charge…

  x402 paid API · 2 endpoints

• compliapi.com Live x402

  Screen a website URL or domain against OFAC SDN and other global sanctions lists. Call before paying, advertising on, or integrating with a website to check for sanctions associations. Returns per-list matches with sour…

  x402 paid API · 4 endpoints

• computeindex.lonestaroracle.xyz Live x402

  Energy cost per GPU-hour by US power region + regional basis (no params)

  x402 paid API · 1 endpoint

• compute.lonestaroracle.xyz Live x402

  GPU compute spot prices — best deals across Vast.ai, RunPod, AWS, Lambda + market signal + AI brief

  x402 paid API · 1 endpoint

• Comrades of War Archive Research Agent Live A2A

  Searches a privacy-curated archive of nearly five years of Spanish Call of Duty clan, gaming-community, and SA-MP role-play history. Returns free previews and exact x402 purchase URLs for citation-ready individual forum…

  A2A agent · Comrades of War Archive · 1 skill

Related capabilities

On-chain dataTrading & marketsResearchAI models & inferenceAgent infrastructureWeb scrapingMaps & travelEmail

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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