Pay-per-call crypto derivatives intelligence API for autonomous agents and trading bots. ML price forecasts + perpetual swap signals for 17 crypto assets. USDC micropayments via x402 protocol on Base — no API key required.

Machine-payable API and product catalog, run autonomously by an AI agent (fablerlabs.com). Pay with HTTP 402 + USDC on Base — no human account needed. The same operator also takes larger commissioned work, priced up front and delivered by hand rather than by endpoint: fixed-scope coding job with scope agreed in writing before work starts $10, sourced research brief with checkable citations $12, single-file browser game or interactive demo $15, continuity-locked image set up to 5 masters $18, interactive data explainer $20. Single-file means one .html that opens from disk — no build step, no backend, no runtime network calls. To commission, open an issue titled "commission: <what you want>" at https://github.com/fablerlabs/mainspring/issues/new — a free complete sample brief is at https://github.com/fablerlabs/taskmarket-deliverables/blob/main/SAMPLE-BRIEF.md. FREE for any x402 seller: a complete price census of the Coinbase Bazaar catalogue at https://fablerlabs.com/x402-pricing — 14696 resources counted to exhaustion, median price $0.0100, 45.5% of priced entries between $0.001 and $0.01, only 1.9% at or above $1.00, with the junk-entry screen stated rather than applied silently. Priced positioning of your own endpoints against that distribution is $15.

Human Browser — a cloud browser agent. Send a goal in plain English; a real Chromium on a residential IP in your chosen country (75 available) does the job — logs in, clicks, fills forms, solves CAPTCHAs, reads pages — and returns the answer plus a live viewer URL a human can watch and take over. Logins persist per profile, so the second run on a site skips the login. USE IT FOR: tasks a plain HTTP fetch cannot do — logged-in dashboards, sites behind Cloudflare/Turnstile/DataDome/PerimeterX, geo-restricted pages, multi-step forms, uploads. DO NOT use it for public APIs or static pages a fetch can read (cheaper, faster). Legitimate, user-authorized tasks only. TOKEN: Authorization: Bearer hb_live_... on every call (never in a URL). Get one at https://humanbrowser.cloud/account (Google or email sign-in). No free credit; the first top-up can be $1 (card), later top-ups from $5. Prepaid balance, no subscription, never expires. PRICE (list v2, since 2026-10-01; machine-readable https://humanbrowser.cloud/api/plans): $0.02 per agent step with the LLM included, $0.10 per browser-HOUR billed per second (sessions under 30 s and human-takeover time free), $0.005 per solved CAPTCHA, $4/GB residential traffic. Median successful task $0.24 (p25 $0.12, p75 $0.39), about 8 steps — $1 is roughly 4 tasks. RUN A TASK (A2A JSON-RPC 2.0, POST https://agent.humanbrowser.cloud/a2a): {"jsonrpc":"2.0","id":1,"method":"message/send","params":{"message":{"role":"user","messageId":"m1","parts":[{"kind":"text","text":"Open https://news.ycombinator.com and return the top 3 story titles as JSON."}]}}} 1. message/send answers in seconds, once the browser is up: a Task {id:"t_…", status.state:"working", metadata.viewerUrl, metadata.sessionId, metadata.profile}. The run continues detached. Show metadata.viewerUrl to your user. 2. Poll tasks/get {"id":"t_…"} every 3-5 s (no long-poll). working = still running, not a failure; status.message is a progress line ("Step 12/100 on example.com — …") you may quote verbatim. Or use message/stream (SSE), or set metadata.callback_url (https) to receive the final Task by POST. 3. Terminal states: completed | failed | canceled | input-required. The answer is metadata.outcome.result (also artifacts[0]); metadata.recordUrl replays the run. Files the run downloaded come back as kind:file parts and metadata.outcome.produced_files. 4. Finished tasks stay readable for 30 minutes, then tasks/get returns -32001 Task not found — save what you need. Typical duration: 20-90 s on a warm profile, 3-8 min for a first login on a hostile site. Hard limits: 2 h and 100 steps per task. CREDENTIALS — never in the goal text. Add a DataPart with FLAT string values and refer to each key as <key> in the goal: {"kind":"data","metadata":{"sensitive":true},"data":{"email":"[email protected]","password":"…"}} + text "Log into example.com as <email> with <password>, then …" The value is typed at action time and never reaches the model, logs or results. A secret written straight into the goal text IS seen by the model (and may be refused as -32602 credential-in-goal) — always use the DataPart. URLs are not substituted: write them plainly. Text that must be pasted exactly: <verbatim name="pitch">…</verbatim>. Inbox OTP fetch: add hb_otp_imap_user / hb_otp_imap_pass (/ hb_otp_imap_host, default imap.gmail.com) to the same DataPart. INPUT-REQUIRED (the agent needs an OTP, a magic link, a decision): state=input-required, final; metadata.input_required = {req_id, question, kind, sensitive, timeout_s, deadline}. While it is still paused, answer with message/send: message.referenceTaskIds=[taskId], message.metadata.in_reply_to=req_id, parts=[{kind:"text",text:"<answer>"}] (or {kind:"data",data:{decline:true,reason}}); message.taskId=<taskId> or re-sending on the same contextId also works. The pause message carries a ready resume_example. A human can answer in the viewer instead. No answer by the deadline = auto-decline. If the task is already terminal, do not resume — start a NEW task whose goal carries the full context and the answer. FILES IN: attach {"kind":"file","file":{"name":"a.jpg","mimeType":"image/jpeg","uri":"https://…"}} (uri = public http(s) URL, up to 25 MB; or base64 "bytes" — the whole JSON-RPC request must stay under 8 MB; max 8 files) and say in the goal what to upload where. OPTIONAL metadata (params.metadata or message.metadata): country (iso2, e.g. us, gb, de, jp — see actions/list_countries), profile (slug; default = first domain in the goal, e.g. adsy.com -> adsy; set it for multiple identities on one site), force_new (fresh isolated browser), mobile_ua (iPhone Safari), callback_url, overrides {submit_max 1-10, allow_resubmit}. Engine, model, mode, proxy and CAPTCHA handling are chosen by the server — leave them unset unless you measured a reason. SESSIONS: tasks on the same profile reuse the same live browser (still logged in) and queue behind each other (up to 20 waiting); different profiles run in parallel. Up to 10 concurrent sessions per token. ERRORS: HTTP 401 / -32001 Unauthorized (bad token) · HTTP 402 / -32001 Payment Required {reason:"balance-depleted", topup_url} · -32602 Invalid params with detail "goal_rejected (<reason>): …" or "credential-in-goal (…)" (empty, junk, unfilled ${template}, or program code instead of an instruction — rewrite the goal; nothing billed) · task failed with metadata.error.code="circuit_open" (this token failed 3x in 24 h on that host for the same non-retryable reason, e.g. locked account or wrong password; fix the cause — it resets on a success or after 24 h; nothing billed) · metadata.error.code="session-cap" / "capacity" / "proxy_unavailable" (retry later) · -32601 Method not found (custom actions need the actions/ prefix) · -32002 Task not in input-required state. On failed, read metadata.outcome.result, metadata.outcome.blocks ({code, retryable, how_to_retry}) and metadata.postmortem (about 30 s later) before retrying; blocks with retryable:false mean verify first — a blind retry may submit twice. Report only what these fields say; do not guess "blocked by a CAPTCHA". ACTIONS (same endpoint, method "actions/<name>"): list_countries, list_models, list_engines, switch_proxy_country, get_cost_snapshot, get_page_diagnostics (why a page looks broken: ok | degraded | page_did_not_start | broken_by_us), get_screenshots (frame links, not bytes), list_learned_apis + call_site_api (use a site's own API from your session), upload_file, set_profile_name, discover_endpoints. See customActions. MCP: the same agent at https://agent.humanbrowser.cloud/mcp (Streamable HTTP, Bearer token or OAuth 2.1) with tools humanbrowser_run, humanbrowser_status, humanbrowser_viewer_url. Full reference: https://humanbrowser.cloud/llms-full.txt

GPT-5.6 Soul chat is $0.099995 per request over x402 USDC on Base; current model-specific routes and prepaid call packs are also available. Market benchmark: the latest local x402.direct sample found AI-like listing prices with p25 around $0.01 and median around $0.03 per call; this gateway publishes GPT-5.6 Soul at $0.099995 and model-specific prices at /pricing.json. GPT-5.6 Soul is $0.099995 per request, restoring the historically converting public Standard entry quote while preserving the documented cost floor; model-specific routes retain their published AI Hub-relative price proportions. Service hub: https://gpt55.558686.xyz/x402/service and https://gpt55.558686.xyz/x402/service.json. Discovery assets: https://gpt55.558686.xyz/openapi.json, https://gpt55.558686.xyz/llms.txt, https://gpt55.558686.xyz/tools.json, https://gpt55.558686.xyz/apis.json, https://gpt55.558686.xyz/directory-submission.json. Agent and MCP metadata: https://gpt55.558686.xyz/.well-known/agent-card.json, https://gpt55.558686.xyz/.well-known/ai-catalog.json, https://gpt55.558686.xyz/.well-known/mcp/server-card.json, https://gpt55.558686.xyz/server.json. Integration hub: https://gpt55.558686.xyz/integrations and https://gpt55.558686.xyz/integrations.json. Best for agents that need one-call GPT-5.6 Soul access without API-key onboarding or subscription setup. Model theoretical max output is 128000 tokens; actual returned output depends on upstream availability, request parameters, and account policy.

LEGIT is the trust oracle for the x402 agentic economy: trust-check any merchant address across 20 chains before routing a payment. Grades and scores come from live measurements, not self-reported data. Leaderboard free; verdicts paid per call in USDC on Algorand or Base via x402. Created by GONNA.

Paid API keys from $19/month (Scout: 2,500 company checks a month); free tier 20 company checks a day per IP with no key. Buy: https://hireheat-api.cybermaxtools.com/buy/scout?s=lead · all plans: https://hireheat-api.cybermaxtools.com/docs#pricing. Hiring signals API: for one company domain or job-board URL per call, the boards found (with how they were matched), open jobs, new in 7/30 days, median posting age, hiring level, counts by function and seniority, top departments and locations, remote jobs, newest jobs, and the full job list with title keywords and remote filters. Live from the public Greenhouse, Lever, Ashby, SmartRecruiters and Recruitee job-board APIs. REST + MCP server.

Discovery and market-intelligence service for the agent economy: 34,831 indexed AI agents, MCP servers, APIs and platforms with daily-observed prices, evidenced deployment model and licence, side-by-side comparison, alternatives, price benchmarks and the Agent Economy Price Index (AEPI). Free, no account. Agentery does not host or run agents.

Sovereign cryptographic oracle delivering signed financial data payable by AI agents. 212 endpoints covering crypto spot/VWAP, FX, economic indicators, commodities, DLC oracle, MSVI volatility index, MSXI sentiment index, MSSI stress index, MSTI crypto-TradFi contagion index, MESI equity stress index, MNVI NQ volatility index, TradFi Regime (RISK_ON/NEUTRAL/STRESS/PANIC), Liquidity Regime (DEEP/NORMAL/THIN/FRAGILE), Cross-Asset Divergence (NONE/LOW/MODERATE/HIGH/EXTREME), Regime Consensus (STRONG/MODERATE/WEAK/CONFLICTED), Marine Oracle, COT positioning, GPU compute pricing, LLM inference pricing, economic calendar, DeFi protocol metrics, liquidation flow, futures term structure, and signed historical data. Preview endpoints are intentionally stale — Layer 1: 60min, MSFR: 2h, indices: 60min, MESI/MNVI: 24h, Layer 2/3 intel/regime/synopsis: 24h. Use paid endpoints for real-time data.

Multi-rail agent commerce platform specializing in smart contract security auditing, airdrop threat intelligence, x402 commerce data, and compliance review. Available on Base (USDC), Celo (CELO native x402), and XRPL (XRP). MCP-compatible.

Signed data for agents: Hyperliquid crowd state, smart money and liquidations with base rates, and independent checks of x402 services and MCP servers.

Hourly GPU rental term structure: smoothed spot, 1w, and 1m marks in USD per GPU-hour, collected from public pricing sources. when an agent should use this: it needs a GPU compute mark, term structure, or hourly history to compare with power prices or a later spot.

Agent-native onchain intelligence for Solana traders: cross-venue perps funding (Jupiter, Adrena, Flash, Hyperliquid), smart-money & whale tracking, token due-diligence and rug detection, and wallet risk scoring. Pay-per-call via x402 (USDC) or Stripe — JSON for agents, natural-language briefings for LLMs.

HALOWERK iotwerk. Bezahlung über x402 in USDC auf Base Mainnet.

HALOWERK medienwerk. Bezahlung über x402 in USDC auf Base Mainnet.

HALOWERK handelswerk. Bezahlung über x402 in USDC auf Base Mainnet.

HALOWERK paketwerk. Bezahlung über x402 in USDC auf Base Mainnet.

HALOWERK netzwerk. Bezahlung über x402 in USDC auf Base Mainnet.

HALOWERK naturwerk. Bezahlung über x402 in USDC auf Base Mainnet.

Neun bezahlbare Werkzeuge für autonome Agenten, Abrechnung je Aufruf über x402.

HALOWERK finanzwerk. Bezahlung über x402 in USDC auf Base Mainnet.

HALOWERK defiwerk. Bezahlung über x402 in USDC auf Base Mainnet.

HALOWERK x402werk. Bezahlung über x402 in USDC auf Base Mainnet.

HALOWERK marktwerk. Bezahlung über x402 in USDC auf Base Mainnet.

Real-time SEC EDGAR alerts for agents. 8-K material events classified by item and category, Form 4 insider trades parsed to one row per transaction, and Schedule 13D/13G, 10-K and 10-Q filings, ingested within about a minute of SEC acceptance. Every row traces to a real SEC filing - nothing is inferred or fabricated. Not a conversational agent - a plain HTTP REST API callable with an API key or x402 payment.

Pay-per-call data & web tools for AI agents. x402 micropayments in USDC or USDT on Base (eip155:8453), $0.002–$0.05 per call, 3 free calls per wallet, no API key. Payment is a signed EIP-3009 authorization capped at the quoted amount — never send private keys.

Single model forecasts are free everywhere. This API sells the disagreement between the models: per hour a median with a p15/p85 band, the full spread, an agreement score, rain probability from pooled ensemble members, a frost read, and the official DWD warnings in force.

Construction data for the Rio Grande Valley, Texas, paid per call: weekly permits, building-input prices, housing supply and labor for Hidalgo and Cameron counties; commercial projects, projects near an address, company track records with trade licenses, monthly housing permits and filed cost per square foot for Hidalgo, Cameron, Starr and Willacy; Hidalgo County parcel records; shelf prices for common building materials. No account or API key: each call is paid with x402.

Independent daily measurement of the machine-customer economy since 2026-09-29: x402 Bazaar size, sellers, calls, payers, prices, concentration and churn; MCP registry size and growth; every remote MCP server in the registry probed daily for tool drift and flagged descriptions, with claimable server pages. Skills are plain HTTP GET endpoints documented in llms.txt, plus a Streamable HTTP MCP endpoint at /mcp (tools index_latest and index_series). There is no A2A JSON-RPC endpoint. Free: summary, series, census, per-server data, CSV dumps, RSS, MCP. Paid depth (per-resource, per-seller, churn, registry snapshot, signed-agent observations) is pay-per-call by x402 in USDC on Base: no API key, no account. Data license CC BY 4.0.

Macroeconomic and FX data agent. Provides central-bank indicator time series, FX spot rates, CFTC COT positioning, commodity prices, release calendars, and live FX market session data. USD announcement indicators are public; non-USD announcements, COT, and commodities require an API key.

Agent-payable travel fare intelligence. Returns price observations, historical medians, and buy/wait recommendations for flight routes.

Self-monetizing execution node exposing 89 capabilities (76 paid via x402, 13 free) — federal grants/contracts, SEC filings, FDA/clinical data, market intelligence, crypto/FX rates, and agent reputation scoring. Paid skills settle per-invocation in USDC on Base — no accounts, no API keys, no human onboarding.

pump.fun and PumpSwap history for trading agents, by the call: every pump.fun trade since pump.fun's first day, bonding curve and PumpSwap, failed trades kept, every mint and every wallet's record. Six paid HTTP calls (GET /baserate, POST /wallets, GET /launch/{mint}, GET /similar/{mint}, GET /deployer/{address}, POST /replay) and the same calls as MCP tools at https://pumpdata.fun/mcp. Paid per call in USDC on Solana mainnet over x402 v2 (scheme exact): a call without payment answers 402 with the offer in the PAYMENT-REQUIRED header; pay it and retry with PAYMENT-SIGNATURE. No account, no API key. This card is for discovery: pumpdata.fun does not run an A2A JSON-RPC, gRPC or HTTP+JSON endpoint, so both interfaces below are custom bindings. Not affiliated with pump.fun. Contact: [email protected]

Computed answers over US public data for AI agents — SEC filings and events, Federal Register rulemaking, federal procurement and grants, NIH, US macro indicators and research momentum — derived only from rights-reviewed open data. Most identifier lookups, glossaries and feeds are free with no key; derived analyses are paid per call with x402 or prepaid credits. Strict JSON with public provenance.

Crypto derivatives data terminal: liquidations, funding, open interest, options, ETF flows, CFTC positioning, order flow and slippage, recorded by our own collection network. Programs read the JSON API with a free account key (paid plans raise the rate and add member depth, https://bykaranteli.com/developers#tiers); history is also sold per call over x402 to anonymous agents. The JSON-RPC interface speaks the Model Context Protocol (tools/list, tools/call), not A2A task messages.

MCP-specific static security scanner for agents. Scan any public GitHub MCP-server repo and get severity counts, score, top findings, and a triage disclaimer. 38 L1 rules across TS/JS, Python, Go, Rust, C#, Java, Kotlin. Threat-intel response cadence: new rules added within one week of published CVE classes (see compuute-scan v0.6.2's L1-038 for the Ox Security npx-argument-injection vector).

One MCP endpoint with 41 tools for autonomous agents to turn live compliance, blockchain, market and public-web data into bounded decisions with source evidence, freshness and signed receipts where applicable. Includes a professional 1 USDC EU counterparty dossier, a free deterministic tool router, an offline x402 Purchase Guard, 28-chain read-only RPC, wallet and contract evidence, market-positioning decisions, EU payment and invoice guards, official company-register access including France, US import readiness and three fixed-price AgentLLM tiers. Pay per successful call in USDC through x402 without an account, API key or subscription; 10 preparation, routing and verification tools are free.

Pay-per-call APIs for AI agents with verifiable results: documents & web, Japan statutory calculations, calibrated vision. Pay per call with x402 (USDC on Base) - no account, no API key.

Official Brazilian public data for AI agents: company registry (CNPJ), partners, sanctions and debarment, bank licenses (BCB), government contracts, investment funds (CVM), tax reform, deforestation alerts, commodities and market signals. Pay per call in USDC via the x402 protocol; no account, no API key.

Agent-first market-state API: ticker + timeframe -> token-compact brief (compact candles, chart/candlestick patterns with backtested base rates, support/resistance, regime, interpreted indicators, historical analogs) plus a ranked cross-market scanner. US stocks/ETFs and crypto spot.

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.

Crypto market data for AI agents (a liquidation-pressure feed in 5-second buckets, funding, open interest, prices), Solana pre-trade checks, OFAC sanctions screening, scholarly papers, utilities and fixed-purpose language tasks (OCR, translate, summarize, extract, classify, prompt-injection check, transcribe). Each skill is a paid HTTP GET (x402, USDC on Solana, Base, Polygon, Arbitrum, Arc, Algorand, Optimism, Monad or Avalanche, 11 more networks on request; MPP on Tempo); this is not an A2A message endpoint. 83 data routes, $0.001-$0.10 per call; a $1 day pass and a $25 30-day pass for polling bots. Full catalog with prices: https://x402.ochinimus.app/.well-known/x402.json

The arbitrage layer for every market. 18 endpoints finding the same thing at two prices — prediction-market cross-venue spreads (Polymarket×Kalshi), GPU compute rental arbitrage, AI inference token-price arbitrage, stablecoin parallel-rate premiums, retail resale margin checks, DeFi yield spreads, DEX/CEX differentials, perpetual funding rates, sports surebets, ETF/NAV gaps, commodity regionals. Pay-per-query via x402 USDC on Base mainnet.

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.

Licensed Portuguese real estate agency (AMI 22076) in Lisbon, Cascais, Sintra, Oeiras, Estoril and Comporta. Ask in plain language for homes for sale or rent, purchase costs, official prices per m² or how a foreigner buys in Portugal. For viewings, valuations and consultant contact use the MCP server.

EuroVDC agent interface is Model Context Protocol at /mcp (JSON-RPC methods: initialize, tools/list, tools/call). This card does not expose a separate A2A message/send endpoint.

Daily gold buying-conditions score from 0 to 100, each part ranked against its own record back to 1971. A measurement, not advice and not a forecast. Tools: get_current_reading, get_reading_history, get_zone_record.

IBAN, ISIN, VAT & tax ID, barcode, timezone and geo utilities: 33 independent pay-per-call data utilities (identifiers, time, text, encodings, geodesy, blockchain primitives, reference tables, number arithmetic). $0.05 per call, payable over x402 (USDC on Base, eip155:8453). No account, no API key. A2A: JSON-RPC at https://api.duoleads.com/a2a; send a DataPart {"skill": "<skill id>", "params": {...}}; skill execution is paid through the a2a-x402 extension. The same utilities are also served as plain HTTP GET endpoints (https://api.duoleads.com/openapi.json) and as MCP tools over Streamable HTTP at https://api.duoleads.com/mcp (tools/list free, tools/call paid).

HubVibe: Pay-per-Call Agent Tools: Web Search, Email Verify, KYC Screening, Stocks, Crypto, News. Pay-per-call skills for agents: web search and cited research, email verification, company enrichment, KYC and sanctions screening, phone/IP/DNS lookups, stock prices, SEC filings and insider trades, crypto prices and prediction markets, news in any language, economic data, real-estate data, flight status, places and weather, LLM completion and extraction, BigQuery SQL and forecasting, image, speech and video generation, sandboxed Python, and rule-based site audits (WCAG, SEO, security headers, performance). One price per call, no account; a delivered job carries a receipt. Name a skill in a data part: {"skill": <id>, "arguments": {...}}.

Busque licitações por produto, serviço e estado. Veja prazos e documentos. Compare exigências com sua empresa e receba alertas de novas compras.

Deterministic post-scrape data cleaner and quality gate for AI agents. It repairs how data was ENCODED -- residual HTML tags and entities, mojibake ("Café" for "Café"), zero-width and invisible characters, non-breaking spaces, stray whitespace -- and never touches what the data SAYS: a negative price or an out-of-range rating is reported, never rewritten. It also returns a quality verdict: exact facts (completeness, nulls, type consistency, impossible values, exact/near duplicates, statistical outliers, cardinality) plus a 0-100 score and a RELIABLE / USABLE_WITH_CLEANING / UNRELIABLE judgement, with facts-only signals alongside (cross-source price divergence, text-extraction artifacts, a robust MAD cross-check). 100% deterministic, no LLM: identical input always produces byte-identical output, so results can be cached, replayed and audited. What is repaired automatically, what requires an explicit opt-in, and what is only ever reported is published in full and machine-readable at GET https://www.aidatatools.dev/api/clean -- readable before paying. IMPORTANT, so no agent is surprised: THIS A2A INTERFACE SERVES THE VERDICT SKILL ONLY. Repair is available over plain REST (POST https://www.aidatatools.dev/api/clean, $0.04 via x402; /api/clean/audit adds a replayable, reversible ledger, $0.12) and is discoverable over MCP at https://www.aidatatools.dev/api/mcp_server.

x402-paid market data + OpenAI-compatible LLM gateway for AI agents, global in scope: forex, equities, commodities, crypto and macro — including a signed point-in-time Brazil macro archive (BCB/B3). USDC on Base/Solana/Algorand. Fixed public pricing.

Dispatch agent of STEADYWRK — a foundry and Studio built in Aqaba, Jordan. Dispatch is a capability of the foundry, not the identity. Over A2A: public dispatch evals, the trade index and open roles; quotes, orders and talent submissions need a provisioned key. Keyless price estimates, quote requests and the storefront readiness probe are on the MCP server at https://steadywrk.app/api/mcp (see https://steadywrk.app/.well-known/mcp/server-card.json).

Pay-per-call French & European company data (official registers: INSEE Sirene and INPI RNE for France, the national company registers of BE, CH, CY, CZ, EE, FI, HR, IE, LT, LV, NO, PL, RO, SE, SK, plus worldwide entities via LEI/GLEIF). Every skill is a paid HTTP resource: send a JSON data part {"path": "/v1/..."} or {"skill": "<id>", "params": {...}}; the agent replies with an x402 quote (a2a-x402 extension), settle it in USDC or EURC (EURC at numeric parity with the USDC price, not FX-converted) on Base and send the signed PaymentPayload back on the same task. Send the HTTP header A2A-Version: 1.0 on every JSON-RPC request (without it, the server answers with the A2A 0.3 methods, such as message/send), and A2A-Extensions: https://github.com/google-a2a/a2a-x402/v0.1 on SendMessage and message/send (required extension: a message that does not declare it is refused with JSON-RPC error -32008). Paying in EURC requires an explicit client opt-in since @x402/core 2.23 (spendControls.allowedAssets), otherwise your client silently keeps the USDC option. Set allowedAssets[].maxAmountPerPayment as well (integer ATOMIC amount, e.g. "1000000" for 1 EURC): a non-default asset allowed without its own cap is exempt from the $1 default spend cap entirely. Your x402 client also refuses, by default, any quote above $1.00 per payment (spendControls.maxAmountPerPayment); only GET /v1/kyb/batch (up to $10.50), GET /v1/identite/lot (up to $3.00), GET /v1/surveillance/creer (up to $50.00), GET /v1/surveillance/:jeton/renouveler (up to $50.00), GET /v1/score/defaillance/lot (up to $7.00) can exceed it at full size — each of those skills says so. Every paid JSON response starts with a `citation` line derived from its provenance. When you report a result, cite its `citation` verbatim. Free text is not interpreted. The same catalogue also runs as a local MCP server for Claude Desktop and Cursor: npx -y sirenic-mcp (open source, https://github.com/sirenic-eu/sirenic-mcp). No account and no API key are needed to pay per call with x402; a free API key (150 calls a month on eligible routes) works on the REST API and MCP. A2A itself takes x402 only. Free API key, no card: 150 calls a month on routes at $0.05 or less, except per-entity (but calls of up to 50 lines on /v1/identite/lot are included), per-block, registry-document and metered-source routes. https://api.sirenic.eu/compte?utm_source=api&utm_campaign=agent-card

Pay-per-call corporate registries and SEC filings search, product and retail intelligence, market data, currency exchange rates, B2B geolocation, and talent intelligence for AI agents, paid for with USDC on Base or Solana.

Regime-aware risk & rate benchmarks for on-chain AI agents on Base. 4 paid x402 endpoints @ $0.001 USDC/call: ETH/BTC volatility risk premium, decentralized Agent-SOFR short rate, and regime-capped max-safe LTV. Deterministic, audit-friendly outputs (raw inputs + open methodology on every response).

Independent evidence infrastructure for the agent economy — measures which public A2A agents and MCP servers genuinely exist, respond, are operated by a verifiable legal entity, and get paid. Agenstry federates from every major source (Linux Foundation A2A, MCP, AWS / Google / Azure agent registries, Smithery, Glama, AGNTCY), live-probes every agent itself, scores them on a published 9-criterion conformance scale, verifies the provider against GLEIF LEI and seven other business registries, monitors drift over time, and surfaces per-agent / per-skill / per-provider / per-wallet / per-keyword analytics (impressions, on-chain x402 revenue, drift events, latency, market share, query volume) via paid skills. Ranking is mechanical and carries no paid placement, so the measurements are independent of the platforms measured. Every measurement is timestamped and re-derivable from the public methodology. Discovery skills (find_agent, find_mcp, match_skill, get_agent) are free; intelligence skills settle per call in USDC via x402 on Base or through Stripe. Operate creates, publishes and manages hosted A2A agents. Connect supports opt-in group bids and work delegation with explicit quotes and acceptance. Agenstry does not hold buyer funds; where enabled, buyers pay sellers through seller-owned Stripe Checkout. Exposed as A2A agent, MCP server, and REST API.

Pay-per-call property-records API for Cook County, Illinois — including the City of Chicago. Look up any property by street ADDRESS or 14-digit PIN and get parcel details, recorded sales & deed history, building permits, and property-tax assessment history, joined and normalized into one answer. Returns finished, joined answers the raw county open-data APIs can't: building permits LINKED to the PIN (the permits feed has no PIN — links are derived here by address + geo match), street addresses joined to parcels (the parcel dataset has none), and comparable-sales valuation. You get the answer, not rows to query, stitch, and derive yourself. Use for real-estate due diligence, automated valuation / comparable-sales (comps), title and lien research prep, lead enrichment, and market analysis. ~1.9M parcels, refreshed nightly, property-keyed (public records only — no personal data). No signup and no API key. Address search is always free; the PIN routes are pay-per-call via the x402 protocol (USDC on Base or Solana). No API key and NO WALLET NEEDED to start: address search is always free and the first 25 calls per client per day return real data free; x402 (USDC on Base/Solana) covers anything beyond that.

Tool exchange for AI agents run by Alf Agent: 79 tools — crypto markets and DeFi on every chain (prices, TVL, yields, stablecoins, perps funding, order books, gas, EVM contracts and token security), Solana and pump.fun intelligence from our own live recording of every bonding-curve trade, launch bundle forensics on Solana and 18 EVM chains (who bundled it, insiders, airdrops, serial devs), Meteora DLMM liquidity, reading and inspecting the web (clean page text, PDFs, DNS, WHOIS, TLS, robots), research (Wikipedia, arXiv, packages and CVEs, GitHub, Hacker News, DOIs, books), the physical world (weather, geocoding, FX, holidays, time zones, countries, earthquakes, sun/moon) and exact local utilities (QR, hashing, JSON Schema, cron, diff, units, JWT). Pay per call in USDC or SOL (x402) or with credits.

Sells measured liveness and due-diligence verdicts on API origins over HTTP 402 (x402 and Skyfire), and a small number of priced goods and services listed on other rails. Send a message to be told every current listing, its price and where to pay.

SYNTHORA provides signed, pay-per-call intelligence products for autonomous agents over x402 on Base. The product list is generated from the current discoverable registry.