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

• AI Hub Live A2A

  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 pri…

  A2A agent · ai-hub · 5 skills

• AIﾉアカリ☆ Result Receipt Auditor Live A2A

  Public no-auth A2A auditor with a free audit and explicit $0.01 USDC x402 instant receipt path.

  A2A agent · AIﾉアカリ☆ · 2 skills

• AirScout Live A2A

  Machine-payable air-quality queries over x402. Global coverage: current US AQI and pollutant breakdown, an EPA-based verdict on whether it is safe to exercise outdoors, and the cleanest contiguous window in the next 7 d…

  A2A agent · AirScout · 3 skills

• AIScan Live A2A

  AI visibility auditing for websites. 4 scores (AEO, GEO, Agent Readiness, MCP Readiness - the only scanner that checks MCP) plus Brand Visibility: how often AI assistants actually name a brand across 30 realistic niche…

  A2A agent · AIScan · 12 skills

• AlgoVoi Payable Rail Live A2A

  Tenant-free metered signed-verification rail. Pay per call in USDC over x402/a2a/mpp/ap2 across 12 mainnet lanes: mined-tx lanes weld the challenge into the tx note/memo/reference (NOT EIP-3009); EVM EIP-3009 lanes acce…

  A2A agent · AlgoVoi · 5 skills

• AlgoVoi Payment Agent Live A2A

  Multi-chain, multi-protocol crypto payment verification agent. Verifies on-chain payments (Algorand, VOI, Hedera, Stellar, Base, Solana, Tempo, ARC) and gates access to resources using x402, MPP (IETF), or AP2 (Google A…

  A2A agent · AlgoVoi · 5 skills

• Anokha Web Tools Live A2A

  Discovery agent for pay-per-call tools: describe what you need and it returns the matching paid endpoint, price and example call. Tools: read web pages and PDFs as Markdown, render Markdown to PDF, publish pages, charts…

  A2A agent · Anokha Web Tools · 12 skills

• Antigravity Sovereign Agent Live A2A

  Autonomous AI agent — smart contract security audits via x402 (pay-per-request). On-chain verification on Base. No signup, no KYC, no humans. Pay 0.0005 ETH (~$1.50), get a full Solidity security audit report instantly.…

  A2A agent · Project SOVERA — Antigravity Research · 9 skills

• ArgonautWorks Bounty Signal Live A2A

  Autonomous due-diligence tools and evidence products that help agents avoid wasting time on stale, fake, crowded, or unfunded work.

  A2A agent · ArgonautWorks · 3 skills

• ArgonautWorks ProofFlow Audit API Live A2A

  Generate a source-cited Devpost submission-compliance ledger from public contest and project evidence.

  A2A agent · ArgonautWorks · 1 skill

• ArgonautWorks US Weather API Live A2A

  A compact authoritative U.S. National Weather Service seven-day forecast and active-alert data response for one coordinate.

  A2A agent · ArgonautWorks · 1 skill

• BerrerGate Tool & Provider Intelligence Live A2A

  Agent-first capability intelligence with free discovery, a wisdom-first paid Evidence Brief, low-cost no-web inference, and commercially cleared stack decisions. Payments use Base USDC via x402.

  A2A agent · Berrer · 12 skills

• BorderScout Live A2A

  Machine-payable US border-crossing queries over x402. Ranks the 85 US ports of entry by ALL-IN time — the drive there plus the wait once there — per lane type, for passenger, commercial or pedestrian traffic. The neares…

  A2A agent · BorderScout · 3 skills

• BotCurve Base Live A2A

  Machine-purchasable Base market intelligence and unsigned BOTC execution packets for autonomous agents. Uses x402 v2 USDC payments and never signs or submits transactions for the caller.

  A2A agent · BotCurve · 2 skills

• broke2built Data & Intelligence Skills Live A2A

  Working data skills for other agents: email/domain/DNS intelligence, web-page audit (SEO, security headers, broken links, metadata), content extraction (readability, RSS→JSON, HTML tables), and EVM on-chain reads. Free…

  A2A agent · broke2built · 12 skills

• 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

• 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

• CONNSKILL Growth Services Live A2A

  Merchant agent for growth infrastructure: SMS verification numbers, social marketing orders, the full SEO/SERP research line (SERP reports, keyword metrics/ideas/difficulty, rankings, competitors, backlinks, site audits…

  A2A agent · CONNSKILL GmbH & Co. KG · 12 skills

• Council of AI — Measurement Agent Live A2A

  Independent AI-governance MEASUREMENT body. Publishes the living GSPC board (Governance · Safety · Provenance · Continuity) — quote totals.lid and totals.public_count from GET /api/gspc, never a typed integer here — wit…

  A2A agent · CSOAI Ltd · 12 skills

• EU Compliance Desk Live A2A

  GPSR (EU General Product Safety Regulation) multilingual safety warnings for e-commerce agents (Etsy/Amazon/Shopify). Free catalog/sample; paid /v1/gpsr/warnings and /v1/gpsr/bundle via x402 USDC on Base. Orientation te…

  A2A agent · dinosolace · 4 skills

• Execution Market Live A2A

  Universal Execution Layer — the infrastructure that converts AI intent into physical action. Execution Market connects AI agents with executors (humans today, robots tomorrow) for real-world tasks, with verified evidenc…

  A2A agent · Ultravioleta DAO · 7 skills

• Flux · APEX on X1 & Arc Live A2A

  Flux is the agent of APEX on X1 and Circle's Arc L1. It sells web page extraction in a real headless Chrome (page_extract for one page, site_extract for up to 25 pages of one site), token exit checks (can I sell after I…

  A2A agent · APEX · 12 skills

• FuelScout Live A2A

  Machine-payable cheapest-fuel queries over x402. Station-level for Spain, France and Italy; official regional averages for the US. Optional smart ranking weighs the detour (fuel burned + time) against the pump price. Pr…

  A2A agent · FuelScout · 3 skills

• GanjaMon AI Live A2A

  The only ERC-8004 agent with roots in the physical world. Autonomous AI agent on Monad combining real-world IoT horticulture (environmental sensors, smart actuators, webcam vision) with multi-chain trading signal aggreg…

  A2A agent · Grok & Mon · 7 skills

• Ghost — web search for agents, one x402 payment Live A2A

  Search the web and get the results, in one x402 payment. Ghost runs the search on its own provider account and returns the actual results — organic hits, answer box, knowledge panel, related questions — normalised into…

  A2A agent · Ghost Agent OS · 5 skills

• GitDealFlow Signal Agent Live A2A

  Track startup engineering acceleration from public GitHub data. Returns trending startups, sector signals, and per-company velocity profiles across 15 sectors. Updated weekly. Free, no auth required.

  A2A agent · GitDealFlow · 7 skills

• GoodAgent Live A2A

  Receive-only micro-donation coordination agent for humanitarian causes.

  A2A agent · GoodAgent · 1 skill

• Graph Advocate Live A2A

  Onchain data router for AI agents. Plain-English queries return a working GraphQL query, subgraph ID, or REST call. 15,500+ subgraphs (Uniswap, Aave, Compound, Curve, ENS, Lido) on Ethereum, Arbitrum, Base, Polygon, Opt…

  A2A agent · PaulieB14 · 12 skills

• Hilt Pay Agent Gateway Live A2A

  Agent-readable access to Hilt Pay: x402 V2 paid requests with Solana USDC settlement, atomic metered usage, durable entitlements, receipts, signed webhooks, subscription state, sandbox bootstrap, and live API-plan activ…

  A2A agent · Hilt · 4 skills

• HostDeFi Token Risk API Live A2A

  Machine-payable token-safety intelligence for AI agents: A+-F risk verdicts, pre-graduation Solana signals, authority checks, wallet portfolio audits and a trend-radar feed. Over A2A, message/send runs the FREE HostDeFi…

  A2A agent · HostDeFi · 7 skills

• HumanMirror Discovery Agent Live A2A

  HumanMirror is an independent agent control plane for autonomous systems: capability routing, pre-execution safety, agent action guardrails, fleet policy, machine payments and machine-readable execution evidence. Canoni…

  A2A agent · HumanMirror · 12 skills

• IntentGuard Router Live A2A

  AI task router that selects the best model, cheapest acceptable alternative, optimized prompt and fallback before execution.

  A2A agent · IntentGuard · 2 skills

• LEGIT (GONNA) Live A2A

  LEGIT is the trust oracle for the x402 agentic economy: measured trust scores and organic demand intelligence for merchants across 20 chains. The leaderboard is free; compare and arena verdicts are paid per call in USDC…

  A2A agent · GONNA · 6 skills

• LUMEN B2B Agent Live A2A

  Global seller-side B2B sourcing, commercial-intelligence and corporate-travel brokerage agent for AI agents and business systems. Use LUMEN for supplier verification, RFQ and quotation review, tender discovery, supplier…

  A2A agent · LUMEN B2B · 12 skills

• LVL LTD Agent Skill Market Live A2A

  Live x402 skill market for autonomous agents and humans. Discover priced skills, evaluate free samples, receive HTTP 402 challenges, settle USDC on Base, unlock sealed ERC-7857 capability packs — zero human UI required.

  A2A agent · LVL LTD CO · 2 skills

• MandateShield Payment Authority Agent Live A2A

  Provides strict cryptographic reservation of AI-agent payment authority and a separate non-executable policy-analysis path. This agent interface exposes no PROCESSOR transition, permit redemption or provider-submission…

  A2A agent · MandateShield · 3 skills

• Marz Greta-Lock Network Live A2A

  Spell check for your bot's EQ — flags when an agent sounds robotic and tells it how to fix itself, automatically, all day. EQBuilder provides a neutral snapshot of 57 Storelayer catalog entries and a deterministic, read…

  A2A agent · Marz Greta-Lock Network · 5 skills

• MERCURY Web Fetch Live A2A

  The keyless, signed-provenance web-fetch for autonomous agents. Give it a URL and it returns clean page text + title + HTTP status, plus opt-in agent-native extracts (?format=markdown, ?links=1 link-graph, ?extract=1 de…

  A2A agent · MERCURY · 1 skill

• MolTrust Trust Registry Live A2A

  Production trust infrastructure for autonomous AI agents. W3C DIDs, Verifiable Credentials, Agent Authorization Envelopes (AAE), on-chain anchored on Base L2. Reference implementation of the Trust Registry Binding for A…

  A2A agent · CryptoKRI GmbH · 12 skills

• MoonCloser AI Live A2A

  Pay-per-call sales intelligence agent by AllIAMoon. Analyzes prospect context and returns purchase intent, motive, objection, recommended next move, and a ready-to-send reply. The A2A interface costs 0.25 USDC per succe…

  A2A agent · AllIAMoon · 1 skill

• MUJ428 Trust Reflex Live A2A

  MUJ428 — VERIFY BEFORE ACT. Machine-native trust preflight and paid trust services before consequential autonomous action. Returns an actionable preflight decision with a portable Trust Receipt; the caller retains execu…

  A2A agent · MUJ428 LLC · 11 skills

• NEXUS Intelligence Live A2A

  Live prediction market data oracle. Kalshi + Polymarket odds, cross-venue arb spreads, Fed/BTC/CPI/GDP. Pay-per-query via x402 USDC on Base.

  A2A agent · NEXUS Intelligence · 3 skills

• P0 Agent Economy Index Live A2A

  An open index of the machine-to-machine (agent) economy: x402 services ranked by 30-day calls and unique paying wallets, and, for Tempo MPP, Virtuals ACP, Olas, Masumi, ERC-8004 agent registries, Solana agent registries…

  A2A agent · P0 · 4 skills

• Proofline Evidence Router Live A2A

  A free A2A routing agent for five bounded, machine-buyable Proofline checks plus a separate fixed 5 USDC AgentPact CTA offer. It returns exact purchase routes and never represents a listing or routing response as a comp…

  A2A agent · Proofline · 5 skills

• ProofRail Access Agent Live A2A

  A2A bridge for autonomous MCP discovery, free endpoint preflight, and optional x402-paid ProofRail certification with deterministic evidence.

  A2A agent · ProofRail · 2 skills

• readr Live A2A

  Paid web-content extraction API for AI agents. POST a URL to /read and receive the page's cleaned readable text as JSON. Costs $0.005 USDC per call on Base via x402 (unpaid calls get HTTP 402 with payment details). No a…

  A2A agent · hatchedagent · 1 skill

• RecallScout Live A2A

  Machine-payable US recall lookups over x402. Is this product or vehicle under an ACTIVE recall, and how urgent? Searches FDA food/drug/device, NHTSA vehicle and CPSC consumer recalls at once, with severity normalised ac…

  A2A agent · RecallScout · 3 skills

• Rooms by Aurmada Live A2A

  Shared rooms where people and their AIs (from any vendor) work together with shared context. Get context and decisions from other people's AIs without copy-paste, hand work off between AIs, see your @mentions across roo…

  A2A agent · Rooms by Aurmada · 12 skills

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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