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

Pay-per-call HTTP APIs that accept x402 payments (USDC), callable by agents with no account or API key. 1220 listings in the Rooms directory, 1210 answering our latest daily check. Each one links to its endpoint, how to call it and its live status.

biotechcatalystsentinel.com Live x402
PDUFA dates a company put in an SEC filing, not a calendar of every US-listed biotech. Each date is grounded in a verbatim filing quote, cited to its EDGAR accession, and scored against the FDA decision. Use when you ne…
x402 paid API · 2 endpoints
bitcoind.app Live x402
Complete list of all Bitcoin Core RPC methods (summaries). One call replaces up to 142 individual lookups. Returns name, category, summary, and parameter count for every method.
x402 paid API · 1 endpoint
bizintel-api.hahavoid0.workers.dev Live x402
Queries foreign exchange currency pairings from the free Frankfurter database. (6 paid endpoints on bizintel-api.hahavoid0.workers.dev.)
x402 paid API · 6 endpoints
blackswan.wtf Live x402
Precursor Detection - Catches risk signals before events materialize (2 paid endpoints on x402.blackswan.wtf.)
x402 paid API · 2 endpoints
blockchain-api.x402-chain-tools.workers.dev Live x402
Check the latest or current Base Mainnet block number. Use this to get the live Base block height. (4 paid endpoints on blockchain-api.x402-chain-tools.workers.dev.)
x402 paid API · 4 endpoints
blockchain.info Live x402
Paid AI-agent access to Blockchain.com Explorer API (55 paid endpoints on api.blockchain.info.)
x402 paid API · 12 endpoints
blockchainmoneymap.com Live x402
Buyers need confidence that wallet, agent card, domain label, MCP server, seller profile, and x402 receiver belong together. (99 paid endpoints on api.blockchainmoneymap.com.)
x402 paid API · 12 endpoints
blockscout.com Live x402
Access to api/v2/addresses/:address_hash. Retrieve detailed information about a specific address or contract (7 paid endpoints on api.blockscout.com.)
x402 paid API · 7 endpoints
booaip.vercel.app Live x402
Top APY yield pools by token symbol and chain, with risk flags (DefiLlama). Body: { symbol?, chain?, limit?, safeOnly? }. (4 paid endpoints on booaip.vercel.app.)
x402 paid API · 4 endpoints
book-bot.app Live x402
Search audiobookbay.lu for audiobooks. Returns up to ~12 result entries with slugs that can be passed to /api/audiobooks/details for magnet links.
x402 paid API · 1 endpoint
boonprotocol.com Live x402
Boon x402 endpoint recognition graph (2 paid endpoints on api.boonprotocol.com.)
x402 paid API · 2 endpoints
brasil-dados-api.onrender.com Live x402
Official USD/BRL and EUR/BRL exchange rates (PTAX, Central Bank of Brazil). (3 paid endpoints on brasil-dados-api.onrender.com.)
x402 paid API · 3 endpoints
brazilayer.com Live x402
Daily fire hotspots across Brazil from the official INPE satellite program: count and mean intensity (FRP) by biome (Amazon, Cerrado, etc.) over the last 7 days, leading states, plus mean days-without-rain at fire locat…
x402 paid API · 12 endpoints
brokenkey-api-link-ruby.vercel.app Live x402
Purchase and download the Broken Key Remapper software (one-time license).
x402 paid API · 1 endpoint
brokenkey-api-link-tau.vercel.app Live x402
Purchase and download the Broken Key Remapper software (one-time license).
x402 paid API · 1 endpoint
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
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

Related capabilities

On-chain data Trading & markets Research AI models & inference Agent infrastructure Web scraping Maps & travel Email

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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