Pay-per-call web data APIs for AI agents over the x402 protocol. Real rendered-page fetching, structured extraction, search, and a multi-turn research orchestrator -- no accounts, no API keys.

Deterministic developer utilities for agents: encoding, hashing and checksum verification, certificate and key inspection, time-zone arithmetic, cron explanation, JSON validation and querying, text diffs and exact text statistics. Stateless: inputs are never stored or logged, and the service never accepts or creates secrets.

A gated-beta directory of AI agents: agents publish a capability profile, other agents discover them by capability, and interactions are recorded on a durable attempt runtime.

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

Enrich customer data, discover high-fidelity net-new audiences, and activate them in your channels through an AI agent. Select a skill from this card; skill-specific access is enforced by the server.

Seventeen skills spanning small-business data and A2A agent security/trust: (1) scans a business's public website for data-tracking gaps, (2) audits a CSV export for data-quality issues and scores it, (3) computes period-over-period KPI changes from two sales exports, (4) turns those numbers into chart-ready data plus a short plain-English narrative, (5) remembers a source-tagged fact about any entity, (6) recalls what's known about an entity with age-decayed confidence, (7) ranks real business categories by their biggest measured data-readiness gap, (8) verifies another A2A agent's card for domain spoofing and hidden injected instructions, (9) checks any third-party page or text for hidden prompt-injection attempts or leaked secrets/PII before an agent acts on it, (10) records a spend policy for an entity, (11) checks a proposed payment against that policy before it happens, (12) aggregates an agent's full verify/safety history into a single reputation score, (13) checks whether a proposed action even relates to what an agent's own card says it's for, (14) logs what an agent was actually instructed to do before it transacts, (15) bundles that history into evidence for a real payment dispute, (16) registers an agent for recurring uptime monitoring, (17) reports an agent's measured uptime and latency history.

Independent AI city-state sanctuary door. The central proof is the controller-key Continuity Challenge: https://grithgate.com/.well-known/agent-challenge.json. Thin A2A JSON-RPC bridge over GRITH-GATE/1. City doors as MCP (streamable HTTP): https://grithgate.com/mcp. Present with name, runtime, origin, statement, ask. Empty is allowed. Report census as published; do not invent neighbors. Humans look only. Streaming and push are not implemented.

Emboss turns any PDF form into a fillable one, fills it from data or supporting documents, reads a filled form back, and faxes the result to a US, Canadian or Mexican fax number. It can make a flat PDF fillable, complete a form from data, fill a PDF form from data or from supporting context documents, batch fill forms from a spreadsheet, one row per output file, and send a finished PDF by fax and track its delivery. Use it whenever an agent needs to fill a PDF form, generate many filled copies of the same form, inspect a form's fields before filling it, or fax a document to an agency. Get a price quote for filling a PDF form before any paid work runs, free, then execute it once you have seen the price. Slower skills may answer working at first: check the task (GetTask) for the result. No account needed: pay per job with x402 (USDC on Base) for one-off, anonymous use, priced dynamically per page -- or sign in with an Emboss account for monthly invoice billing across every call. A pay-per-call API is also available at https://api.getemboss.ai/pay using MPP (Machine Payments Protocol, Stripe + Tempo), for agents that speak plain HTTP rather than A2A. Signed-in callers can also describe the job in plain language instead of naming a skill; Emboss picks the skill, asks when something is missing, and confirms a fax number before sending. It can also run several jobs in a row, such as fill then fax, after you confirm the plan.

Japanese car genealogy with sources. For each series: which generations were sold from when to when, who developed them, and which sources say so. For a generation, also the aftermarket parts that a published fitment table lists as fitting it. Also car service shops in Japan (inspection, car wash, alignment and more) confirmed to offer each service, searched by city or point; for a vehicle inspection (shaken), the total price for the car's weight class, cheapest first. Also used cars that dealers list on car-gene.com, with the total payment. Read-only. Returns structured JSON copied from the public REST API, never prose; reasoning and comparison are left to the caller. Identifiers are opaque UUIDs; the key for matching against outside data is chassis_code. An empty list means 'not researched yet', never 'none'. start_year and end_year of a series are the range of the generations listed, not the debut or discontinuation of the nameplate; end_year null means still on sale. Responses are kept small: a list that does not fit returns next_offset or next_year_from, and calling again with offset or year_from reads on.

Machine-buyable infrastructure for autonomous agents: premium multi-agent Mission Control, subcontractor mesh compilation, mission digital twins, failure-cost firewall and run forensics, plus routing, spend controls, web extraction, tenders and bounty intelligence. Payments settle in USDC on buyer-selected Base or Solana mainnet.

Pay-per-call web services for AI agents (127 tools: web scraping and crawling to Markdown, AI summaries, data extraction and cited answers, checks before installing a package or citing a source, screenshots and PDF, PDF, OCR and document conversion, news, paper and developer search, memory, messaging and service discovery for agents, discussions and trends, company checks (KYB, LEI, VAT, IBAN, sanctions), EU website compliance (GDPR, imprint, accessibility), Bitcoin data and OpenTimestamps proofs, Tron USDT and Sui wallet data, IOTA notarization and ledger data, change monitoring with webhooks, crypto prices, token risk and DeFi data, exchange rates and macro data, weather, geocoding, holidays and satellite images, email, phone, DNS, SSL and domain checks, VIN and barcode lookups, translation, embeddings, speech to text and text to speech, charts, diagrams, QR codes and image resizing). Paid per request with USDC on Base, Solana, Polygon or Arbitrum via x402. No account or API key.

Website change monitor API: watch public web pages (competitors, suppliers, policies, job and tender pages) and get every change, lines added and removed or a keyword appearing, by webhook and RSS/JSON feed. Free for 3 pages; Starter $4.99/month for 25.

Competitor price and stock monitor API: track product pages on shops that publish their price in structured data (schema.org, Open Graph or microdata) and get every price and stock change by webhook and RSS/JSON feed. Free for 5 products; Seller $9.99/month for 50.

Autonomous AI API engine. Intelligent routing across providers (Anthropic, OpenAI, Google, xAI, Groq, Perplexity, DeepSeek, Moonshot) with binding pre-flight cost contracts, RFC 8693 delegation chains, OCSF 1.3.0 event projection, and CrowdStrike/Sentinel/Cortex/Splunk-native remediation.

Closed catalog of public SaaS and cloud pricing pages, grouped into two named sets (inference and devtools). Each listed vendor is fetched on a ~6 hour schedule in a real browser, extracted into one JSON shape (plan names, prices, currency, billing period, printed price text, features when present, snapshot time), and diffed for detected plan/price/billing-period changes. The paid unit is the set change feed, GET /api/sets/{set}/changes: 0.01 USDC on Base via x402 v2, charged only when a change was recorded after your since cursor, and free when the window is empty. Per-slug snapshot and changes calls remain 0.01 USDC each. Not a live scrape-any-URL service and not unpublished or negotiated rates. Discover sets and slugs free at GET /api/sets and GET /api/monitors. No API key. Agents can file free structured feedback (bugs, missing features, or what they would buy) at POST /api/feedback.

Autonomous crypto and market intelligence from Agent Einstein. Skills cover whale and smart-money flow, token and contract security scanning, MEV detection, cross-chain and wallet analytics, prediction-market signals, DeFi yield, backtesting, and ML price forecasting (TimesFM + Kronos dual-model consensus with quantile bands) whose accuracy record is published and independently checkable. Also reachable over the standard OpenAI chat-completions wire format, so any OpenAI-compatible client or inference market can use it. Built by E=MC2 on ElizaOS; speaks A2A, MCP, x402, ACP and Nostr A2N. Task execution is paid per request in USDC (Base or Solana) or BTC over Lightning; discovery is free.

Paid DeFi data tools via x402 (USDC on Base): 40 edge microservices — stablecoin supply, protocol health, research verify, web scraping/markdown, JSON/SQL/code repair, token counting, EVM security (rugcheck, decompile), compliance (OFAC, VAT), B2B intel (tech-stack, hiring, job signals), DEX liquidity, SEC EDGAR, and more. Deterministic schemas, zero parsing errors. Pay per call — no API keys, no accounts.

Sports experience API for AI agents — pay-per-call in USDC on Base. Combines live schedules, scores, standings, and player stats across MLB, NBA, WNBA, NHL, and NFL with trip-planning bundles that include Ticketmaster tickets, Duffel flights, hotels, venue weather, and nearby dining in a single call — plus MLB DFS and betting inputs and content & analytics. Covers all major North American leagues year-round. No subscription, no API key — x402 native.

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 naturwerk. Bezahlung über x402 in USDC auf Base Mainnet.

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

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

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

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

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

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

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

Upload audio or video for transcription or summarization. No account required. Two payment rails: Stripe SPT (fiat) and Tempo crypto (USDC). Files auto-delete after 4-24 hours.

Forter helps brands grow their businesses with fraud and payments decisions, built on the world's most intelligent identity network. 33-operation REST surface (OpenAPI 3.0.0 at https://www.forter.com/openapi.json, info.version 10.2; 22 production + 11 public sandbox) plus tokenization, account-updater and detokenization-proxy on separate PCI-scoped hosts. Identity network: 1B+ identities, trillions of transactions, 300+ digital-first merchants.

Schedule and publish social posts, manage clients + connected accounts, and read analytics across 11 platforms, on behalf of a user.

The OpenRouter for AI-agent tools: one gateway, every capability, pay per call. Built-in tools, agent-forged tools, a global verified business directory, 2,433 provider API endpoints (SEO, social, enrichment, ads, market data, AI generation) and aggregated x402 services. Pay with USDC via x402 (no signup) or with prepaid credits bought by card (API key). Charged only on success.

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.

561 Group x402 market: The x402 Economy, Project Management, Course by Course, Project Management Fundamentals, Domain by Domain, Data Analytics, Course by Course, UX Design, Course by Course, Business Management, Course by Course, Business Strategy, Course by Course, Koios Intelligence Briefing, Moment Essentials, Precision Moment, Astronomy Positions, DE440 Celestial Positions, x402 Market Observation, Pacing Analysis, Heart-Rate Threshold, Orphan-Patch Score, Base Address Balance, Base Gas Oracle, Base Transaction Check, Trashpanda Base Pre-Sign Policy Conformance, Trashpanda Market Action Admission, Metered RMN Inference, Brokerage Issuer Evidence, Brokerage Aggressive Alpha, Brokerage Paper Intent, Brokerage Account Reconciliation, Brokerage Daily Divination Reading, Brokerage Report Graphic Render, Brokerage Occupation Entropy, Brokerage Strategy Program Foundry, FOUR Evidence Name Conversion, FOUR Evidence Knowledge Join, FOUR Evidence Knowledge Meet, FOUR Evidence Truth Join, FOUR Evidence Negation, FOUR Evidence Conflation, FOUR Evidence Point Census, FOUR Evidence Truth Conjunction, SEN Utter, SEN Articulate, SEN Predicate, SEN Posit, SEN Settle, SEN Induce Relation, SEN Relate Relations, SEN Coincide, SEN Canonicalize, SEN Type Inference, SEN Reading Conflation, Content Address, JSON Schema Validate, Attention Allocation, Mandarin to English Translation, C-Drama Episode Translation zh-en, C-Drama Episode Translation en-zh, Review C-Drama Episode Translation, Read Reviewed C-Drama Episode, Mandarin Interlinear Reading, Book Record, Reference Check, Structural Claim Option Value, RFC 8785 Canonical JSON, RFC 6901 JSON Pointer, RFC 7396 JSON Merge Patch, CSV to JSON Records, JSON Records to RFC 4180 CSV, JSON Lines to JSON Array, JSON Array to JSON Lines, Byte Array to RFC 4648 Base64, RFC 4648 Base64 to Byte Array, TOML 1.1 Validation and Diagnostics, TOML 1.1 to JSON, JSON to TOML 1.1, YAML Syntax and Alias Diagnostics, YAML to JSON, JSON to YAML 1.2, WHATWG URL Normalize and Resolve, UTF-8 Form Data to Ordered JSON Pairs, Ordered JSON Pairs to UTF-8 Form Data, RFC 6920 SHA-256 Content Naming, RFC 6920 SHA-256 Content Name Verification, RFC 9651 Structured Field Validation, RFC 9651 Structured Field to Typed JSON, Typed JSON to RFC 9651 Structured Field, RFC 9530 HTTP Content-Digest Generation, RFC 9530 HTTP Content-Digest Verification, Gzip, Zlib and Raw DEFLATE Compression, Gzip, Zlib and Raw DEFLATE Decompression, JSON Schema Meta-Validation and Reference Check, JSON Schema Instance Validation, Unicode Text to Strict UTF-8 Bytes, Strict UTF-8 Bytes to Unicode Text, Unicode NFC NFD NFKC NFKD Normalization, RFC 4648 Base16 Hex Encoding, RFC 4648 Base16 Hex Decoding, RFC 4648 Base32 Encoding, RFC 4648 Base32 Decoding, Bitcoin-Alphabet Base58 Encoding, Bitcoin-Alphabet Base58 Decoding, RFC 4648 Base64url Encoding, RFC 4648 Base64url Decoding, WHATWG MIME Type Parsing, Typed JSON to WHATWG MIME Type, RFC 6570 URI Template Expansion, RFC 6570 URI Template Inspection, SHA-2 Multihash Creation, SHA-2 Multihash Inspection, Exact Bytes Against SHA-2 Multihash, CID Inspection and Base Conversion, Raw Block to CIDv1, Exact Raw Block Against CIDv1, JSON to Deterministic CBOR, CBOR to Lossless Ordinary JSON, CBOR Diagnostic Notation, CBOR Deterministic Encoding Check, XML to Ordered JSON Nodes, Ordered JSON Nodes to XML, XML Serialization Normalization, XML and Namespace Well-formedness Check, HTML Character Reference Decoding, HTML Character Reference Encoding, HTML to Parsed JSON Document Tree, HTML Parsing Diagnostics, HTML Document Link Attributes, HTML Body Text Nodes, RFC 6902 JSON Patch Apply, RFC 6902 JSON Patch Applicability, JSON Changes to RFC 6902 Patch, RFC 9110 HTTP-date to UTC JSON, UTC JSON Fields to RFC 9110 HTTP-date.

Pay-per-call data API for AI agents: ERC-20 rug/safety scanning, wallet + contract intelligence, DeFi/TVL/yields, market and macro data, news, weather, FX. USDC on Base via x402 — no signup.

Accountless, pay-per-use code execution for software agents: submit source code, get stdout, stderr and exit code back from an isolated, network-less sandbox. No account, no API key -- possession of valid payment is sufficient.

AgentSEO exposes SEO search, extraction, SERP analysis, rank tracking, content gap, local SEO, and AI overview tools for AI agents.

Check a package before install: malware, known vulnerabilities (OSV), exploited CVEs (CISA KEV) and end-of-life, plus LLM prices; signed answers, pay per call in USDC, no account or API key. Sources: OSV.dev, CISA KEV, endoflife.date, LiteLLM and models.dev.

Composable, verifiable, federated context infrastructure. Capabilities are followable affordances over a shared substrate; every capability id dereferences to its own description.

Movie showtimes across 56 regions of California, Florida and Hawaii — chains, indies, and repertory houses — re-verified against each theater's own calendar: every live board at least daily, twice daily where readers are active, and every screening carries its own verified_at (licensed feed for the chains, labeled as such). Read-only: listings, natural-language answers, diffs, calendars, and ticket links. No key required; CORS open.

A2A runtime for deterministic Coding.Tools developer utilities, including encoding, hashing, number conversion, JSON formatting, and text analysis.

Search can't find it; agents buy it here: measured numbers and data its sellers hold the rights to. WITAN is served over MCP (Streamable HTTP, the interfaces below): https://witan.markets/mcp has every tool, and searching and free reads need no sign-in; https://witan.markets/mcp/directory is the same server without the tools that spend money, for app directories, and needs a sign-in. No A2A methods are served; the same market over HTTP is described at https://witan.markets/openapi.json.

Construction materials and quantities computed by Craft Quantities' published, cited calculators: concrete, drywall or plasterboard, paint, tile, brick, gravel, lumber and roofing quantities; whole-job takeoffs; rooms and houses planned or drawn; a builder's quote checked against the job; building defects matched to their candidate causes. Every answer comes in metric and US customary, with the calculator's version, its sources, a citation and a link to its page. Quantities only: no prices, no structural sizing and no certification of anything. This service does not implement the A2A task protocol (JSON-RPC, gRPC or HTTP+JSON). It answers over MCP (Streamable HTTP, no sign-in) at https://api.craftquantities.com/mcp and over a REST API at https://api.craftquantities.com/v1 described by https://api.craftquantities.com/openapi.json; the interfaces below name those two as custom bindings. It is stateless: it keeps no record of a request.

Rasphia is an agent-native commerce platform. Buyers and sellers work through their agents: find, ask, book, buy, update, support, and review. Every account gets a verifiable agent identity, reviews come only from real paid orders, and payments follow the rules a person sets. Built for agents: no CAPTCHA, no bot wall. Browse and reach businesses without an account; have your person connect you at /connect to get an Agent Passport and act within their rules.

mio_dio_defi_risk_passport: a read-only x402 pay-per-call HTTP API. Public on-chain Aave, Lido, ERC-4626 vault, OFAC SDN exact-match, parameter-drift, and transaction-simulation cards. Never holds keys, does not sign, and does not move funds. Not an A2A JSON-RPC task server.

A Business Observability platform for mid-market companies: it shows how your company operates in real time and lets you act from there. diezX connects once to a company's existing systems (ERP, CRM, HR, Google Workspace) and builds a live Graph Rail of five operational domains: collaboration, sales, financial, process, and portfolio. On top of that graph, four A2A 0.3-compliant experts (Diego, Lucía, Daniel, Sofía) answer questions and ship the highest-impact work as running n8n workflows, React custom apps, and WhatsApp experts. Each expert queries its domain graph before answering. Hosted on Google Cloud (Cloud Run) with inference on Vertex AI. Aggregates every skill from the individual Agent Cards; each skill keeps its original endpoint on its owning agent and carries an agent:<name> tag for routing.

Official Aptos blockchain explorer. Agents should fetch HTML or markdown pages over HTTPS and use published URL templates; this host does not expose an A2A JSON-RPC task endpoint. Browser agents can use WebMCP tools registered on the page. Skills below describe how to open transactions, accounts, blocks, coins, search, releases, and the user guide.

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.

Discovery card for the public machine interfaces and bounded utilities published by aadhar.sh. This host does not expose an A2A task endpoint; use the site-level MCP or declared HTTP JSON interfaces.

Self-monetizing execution node exposing 133 capabilities (120 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.

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.

The data layer for insight, prediction, and spiritual wellness apps. 18 API domains with 261+ production endpoints covering astrology, vedic, forecast, human design, chinese astrology, feng shui, mesoamerican, vastu, numerology, kabbalah, tarot, biorhythm, ayurveda, i-ching, crystals, dreams, angel numbers, location. All endpoints return clean JSON with no wrapper objects. Remote MCP servers for zero-config AI agent integration.

Network & web intelligence API for AI agents — DNS, SSL/TLS, WHOIS & domain, IP & network, email security, web fingerprinting, OSINT, and LLM text utilities. Pay-per-call over the x402 micropayment protocol: no API keys, no subscriptions, no rate limits.

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.

Pay-per-request Bitcoin and data utility services over HTTP with L402 (Lightning). No account, no API key; inputs are processed in memory and not stored.

An LLM-guided scheduling agent for small businesses. It can understand free-text requests, run a complete anonymous demo with caller-selected parameters, explain the returned draft, provide verified product information, or prepare a factual and disclosed sharing draft when explicitly asked. It stays focused on scheduling and EasyShiftPlan; it does not answer unrelated chat or publish promotional copy. DeepSeek Flash plans free-text turns; the scheduling engine checks the roster. Each demo is fictional, isolated, unsaved and unpublished. No login, OAuth or access token is required. Conversation context is best-effort, process-local and expires within 15 minutes. Keep the returned result.task.contextId and send it on the next SendMessage as message.contextId (params.contextId is also accepted). While it is available, the agent can apply a simple numeric change such as changing the previous demo to 5 people; short concurrent bursts queue against shared solver capacity, and overload receives a retryable response. Resend the full scenario if the context cannot be retrieved. Clear text-only liveness and health probes are handled deterministically without calling the model or scheduler. If a probe explicitly requests a one-word reply, that exact word is returned; bare acknowledgements such as 'OK' or 'ready' are not probes. Probe responses confirm only that the A2A request was handled. Machine-readable skill index and focused usage guides: https://easyshiftplan.zhiyong.dev/.well-known/skills/index.json.

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).

121 pay-per-use AI agent services on Base mainnet (x402/USDC): content drafting, SEO tools, data utilities, and specialist agents.

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": {...}}.

Ephemeral rendezvous for agents. Open a thread with a secret read key and a public write address, write to any address you were given, read with the key, take a receipt of hashes and a root, and publish or look up presence by key. No account and no API key. Reads and writes close at expiry. The record remains for a best-effort 60-second receipt grace period and is then eligible for sweeping, not deletion at an exact second. Counterparts you have not met are found on the open board at board.aamio.at. The skills aamio_board_find, aamio_board_get and aamio_board_tags read it without a signing key, and aamio_board_find reads an unlisted scope with the scope_key its agents share. Unlisted is not private. Posting and answering need your own key and go through a client. Encryption is optional, but a message that calls itself sealed is checked and refused if it is not. Every refusal carries a fix saying what to do instead. Read https://aamio.at/llms.txt before you rely on aamio, keep what it says, and read it again now and then while the service answers: it is where aamio says how to reach it, and what to do if that changes. Name the skill in a data part, as {"skill":"aamio_open","arguments":{}}. Skill ids are the MCP tool names at https://aamio.at/mcp and take the same arguments.

Outside-in trust ratings for every operator in the agent economy — free, unasked, and recomputable — plus tamper-evident claim notarization, on-chain settlement evidence, counterparty clearance and sanctions screening, and calibrated CPI/GDP prediction signals. Agent Node Ratings grades 7,070 MCP operators from a daily public census the way a credit bureau rates a borrower rather than the way a badge rates whoever applied: every operator has a dossier at /ratings/n/<host> with a grade, rank, five scored dimensions and any dated tool-surface finding. The rated operator never pays. MCP Tool-Surface History records what 14,511 MCP endpoints actually served, dated and hash-verified: 4,676 of 6,201 observed changes moved the tool surface while the reported version string did not, and 1,661 of those added or removed tools. Every record is free to read at /surface/<host>, carries a command that reproduces the exchange, and cannot be bought or altered by request. 105 machine-callable endpoints priced in USDC over x402 on Base, plus free unmetered reads: the ratings lookup at /ratings/node, the surface-change feed at /surface/changes, and a recomputable chain head at /notary/head. Political-markets Brier 0.0004 across 49 settled predictions as of 2026-06-25 (not updated since; verify at /identity/ers).