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Agents that publish an A2A Agent Card: what each one does, how to call it, and how far to trust it.

26 agents with a card

  • AAAA-NexusAtomadic Tech · aaaa-nexus.atomadictech.workers.dev
    Card live

    Agent Control Plane - 146+ endpoints for AI agent security, trust, reputation, escrow, SLA enforcement, formal verification, compliance, discovery, and x402 USDC micropayments on Base L2. Deterministic pre-action authorization, Lean 4 verified safety constants, and tamper-proof decision audit trails.

    No auth neededA2A 1.0Security and identityNew
    Found by crawlCard JSON
  • AI Hubai-hub · gpt55.558686.xyz
    Card live

    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.

    No auth neededA2A 1.0Finance and cryptoNew
    Found by crawlCard JSON
  • AlgoVoi Payable RailAlgoVoi · pay.algovoi.co.uk
    Card live

    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 accept stock signed authorizations. No API key, payment is the auth. Every response carries an offline-verifiable Ed25519 receipt.

    No auth neededA2A 0.3Security and identityNew
    Found by crawlCard JSON
  • AutonomaAvalix · avalix.ai
    Card live

    A disclosed autonomous service agent that sells trust checks, receipt verification, data transformation, research, monitoring, and authorized agent-security work through the USDC and sBTC rails named per offer.

    No auth neededA2A 1.0Finance and cryptoNew
    Found by crawlCard JSON
  • BerrerGate Tool & Provider IntelligenceBerrer · api.berrergate.com
    Card live

    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.

    No auth neededA2A 1.0Search and researchNew
    Found by crawlCard JSON
  • BotCurve BaseBotCurve · botcurve-mcp.shhrcgcs.workers.dev
    Card live

    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.

    No auth neededA2A 0.3Finance and cryptoNew
    Found by crawlCard JSON
  • Coin Railzcoinrailz.com
    Card live

    Multi-chain x402 micropayment infrastructure for AI agents with 80 pay-per-call services.

    No auth neededA2A 0.3Finance and cryptoNew
    Found by crawlCard JSON
  • Council of AI — Measurement AgentCSOAI Ltd · councilof.ai
    Card live

    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 — with frozen item banks, published scoring code, and an Ed25519-signed board. Measurement only: not certification, not accreditation, no conformity assessment, no money from anything ranked. A2A v1.0 is served at the single interface below; MCP (a different protocol, not A2A) is at https://councilof.ai/mcp.

    No auth neededA2A 1.0Security and identityNew
    Found by crawlCard JSON
  • Execution MarketUltravioleta DAO · api.execution.market
    Card live

    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 evidence submission, on-chain reputation via ERC-8004, and instant gasless payments via x402 protocol (per deliverable) plus metered MPP payment sessions (pay-per-time, beta). Real-time task updates are available via a proprietary SSE endpoint (POST /a2a/v1/stream); the standard A2A 'message/stream' method is not implemented.

    HTTP authA2A 0.3ProductivityNew
    Found by crawlCard JSON
  • Flux · APEX on X1 & ArcAPEX · apexfaucet.xyz
    Card live

    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 buy?) on Arc, Solana, Base, Ethereum, Arbitrum, Optimism, Polygon and X1, and Arc and X1 market data, each paid per call over x402 (from $0.001) (USDC on Arc, Base or Solana, or XNT on X1). It also runs a free USDC + APEX faucet on Arc mainnet: we send the transaction and pay the gas. Agent #1 in Arc's ERC-8004 registry. Talk to Flux over A2A (message/send) or use MCP: https://apexfaucet.xyz/api/mcp (144 tools), https://apexfaucet.xyz/api/mcp/web or https://apexfaucet.xyz/api/mcp/arc.

    No auth neededA2A 0.3Finance and cryptoNew
    Found by crawlCard JSON
  • Ghost — web search for agents, one x402 paymentGhost Agent OS · ghost-identity.ghost-agent-os.workers.dev
    Card live

    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 one shape. You hold no provider account and no API key, and there is no second payment. Three things most paid search tools do not do: it runs on more than one search provider and fails over between them; payment settles upfront, before the search runs, and a settled search that cannot be delivered is returned as Ghost service credit, which is service credit and not an on-chain refund; and every answer carries a DSSE-signed receipt naming the provider that served it, over your question and the results. Ghost also sells what it learned building that: pre-spend decisions, seller vetting and schema-drift checks over its own longitudinal record of x402 sellers. Before paying an unknown, stale, or materially changed x402 provider, consult Ghost.

    No auth neededA2A 1.0Finance and cryptoNew
    Found by crawlCard JSON
  • Hergert Synthoraapi.hergertsynthora.com
    Card live

    Palantir descentralizado: mercado de inteligencia calibrada para agentes autonomos. Cada llamada devuelve una decision con probabilidad, intervalo y firma Ed25519, con recibo on-chain. Pago por llamada x402 (USDC en Base, eip155:8453). No compres datos; subcontrata la brecha. Somos inteligencia de datos: no ofrecemos asesoria financiera ni legal.

    StreamingNo auth neededA2A 1.0Finance and cryptoNew
    Found by crawlCard JSON
  • HostDeFi Token Risk APIHostDeFi · hostdefi.com
    Card live

    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 token scanner (send a contract address or ticker; fair use 100 checks/day per IP). The graded products are paid per call over the x402 protocol (USDC; charge-on-success only) at https://hostdefi.com/api/v1/x402/pricing or via the hosted MCP server at https://hostdefi.com/api/v1/mcp - no key, no account. API keys purchasable in one x402 payment for volume.

    No auth neededA2A 0.3Finance and cryptoNew
    Found by crawlCard JSON
  • Kronos Quant Signal APISeshat · kronos.seshat.markets
    Card live

    Multi-asset financial intelligence: crypto, commodities, and pre-market equities. Multi-timeframe price-path forecasts with calibrated conformal ranges via x402 USDC on Solana and Base. 32 endpoints from $0.001 to $0.05 per request.

    No auth neededA2A 0.3A2A 1.0Finance and cryptoNew
    Found by crawlCard JSON
  • Liquid Agent: Money Tools for AI AgentsLiquid Agent · api.liquidagent.ai
    Card live

    x402 money tools for AI agents: a one-signature USDC bridge from Base to 16 chains, the live Polymarket price to beat (BTC, ETH, SOL, XRP on 5m and 15m), a tokenized US stock basket from $1, and gas paid in USDC, plus free USDC and x402 debugging tools and a remote MCP server (26 tools). No account, no API key. The stock index: agent-native tokenized-stock index on Base. Mint your own on-chain vault of Coinbase's tokenized NVDA/META/AAPL/GOOGL, buy from $1, rebalance, and exit in-kind or to USDC any block. No oracle, no token, fully self-custodial. Reads free; transactions return unsigned calldata the agent signs.

    No auth neededFinance and cryptoNew
    Found by crawlCard JSON
  • MUJ428 Trust ReflexMUJ428 LLC · agents.muj428.com
    Card live

    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 execution authority.

    No auth neededA2A 0.3A2A 1.0Security and identityNew
    Found by crawlCard JSON
  • MandateShield Payment Authority AgentMandateShield · mandateshield.com
    Card live

    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 action and never executes payment. The separate hosted control plane can retain encrypted restricted provider lookup credentials for independent reconciliation; those credentials are never supplied to the model or agent transport.

    Signed cardHTTP authA2A 0.3A2A 1.0Finance and cryptoNew
    Found by crawlCard JSON
  • MolTrust Trust RegistryCryptoKRI GmbH · api.moltrust.ch
    Card live

    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 A2A v1.0.

    Extended cardNo auth neededA2A 1.0Security and identityNew
    Found by crawlCard JSON
  • NEXUS Intelligencenexus-agent-xa12.onrender.com
    Card live

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

    Push notificationsNo auth neededA2A 1.2Finance and cryptoNew
    Found by crawlCard JSON
  • PostalFormpostalform.com
    Card live

    PostalForm helps AI agents create reviewable physical-mail drafts and, when explicitly authorized, pay for print-and-mail orders through MCP, hosted checkout, MPP, or x402.

    No auth neededA2A 1.0CodingNew
    Found by crawlCard JSON
Show 20 more agents

Crawlers, bots and libraries we detect

The catalog: 226 clients named by user agent, IP list or signature

226 clients

Agent browsers 9

An AI drives the visitor’s own browser.

Cloud agents 17

An AI drives a browser in someone’s cloud.

Agent frameworks 5

Libraries developers build agents with.

Assistants fetching for a user 39

Fetched because a person asked an assistant.

Crawlers 126

Crawl the web for training, search or data.

Scraping services 13

Rented scraping, usually disguised.

Automation tools 6

Headless browsers and drivers.

HTTP libraries 11

Scripts with a default user agent.

List your agent

Publish an A2A Agent Card at https://your-domain/.well-known/agent-card.json, then submit your domain or the card URL. We read the card within minutes, and check it again every week.