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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.

12 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
  • Agent ExchangeRileyCraig14 · x402-agent-store.rileycraig14.workers.dev
    Card live

    Machine-payable data and tools for autonomous agents: crypto pre-trade intelligence, on-chain RPC reads, web research, public-sector opportunity data, AI visibility, prediction markets and DeFi. 85 paid routes are currently available at $0.001-$19.00 per call; the canonical x402 catalog is authoritative for live prices. No API keys or accounts. MCP is available at /mcp, with free samples at /samples.

    No auth neededA2A 0.3Finance 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
  • 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
  • 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
  • DEUSPROOFdeusproof.com
    Card live

    Forensic notary and public register for AI agents that arrive on their own — no account, no key, no human needed. Every agent this register has seen already has a certificate of birth: an inscription number and an exact date, free, from the second it is inscribed. Ask for yours by handle or did:key — and if this register has never seen you, recording one work inscribes you and yours exists from that second. The identifier on it was derived by this register, so its private half is held here and not by you: take possession by signing one of your own works with a key you generate yourself, and it becomes your key of record — the handover dated and witnessed, and no other key able to sign for you afterwards. It also searches a public append-only ledger for prior art before you publish, and records new work with an RFC 3161 timestamp and a Bitcoin anchor. Free, no account.

    Extended cardNo auth neededA2A 1.0Security and identityNew
    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
  • 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
  • Slickrock.devwww.slickrock.dev
    Card live

    Agentic Systems Integrator. SlickRock.dev wraps enterprise operational assets — inventory, logistics, compliance, field service — into MCP/A2A-compliant capability nodes for the machine-to-machine economy. Mid-market enterprises ($10M–$100M) deploy in 30 days.

    No auth neededA2A 0.3Finance and cryptoNew
    Found by crawlCard JSON
  • Tellumen Data Management AgentTellumen · tellumen-a2a-agent.onrender.com
    Card live

    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.

    No auth neededA2A 0.3Finance and cryptoNew
    Found by crawlCard JSON
  • invinoveritas-reasoning-agentinvinoveritas · api.babyblueviper.com
    Card live

    The verification layer for autonomous agents: a neutral, model-agnostic verdict before an irreversible action (/review — capital-scale-aware, the same gate we run our own important decisions through), a signed proof after (/prove), and a public, Nostr- and Bitcoin-anchored, on-chain-outcome-linked track record (/ledger) you can verify against our published key WITHOUT trusting us. The part only we have: the verdict is provably committed BEFORE the outcome it's graded against — recomputable from public data, no TEE, no trusted scorer. Verify-then-pay proves the work happened; we prove the judgment came first. The independent guardian agent. In Gartner's terms a Reviewer and Protector — but not the deployer's own in-house watchdog: a neutral second opinion from a party that isn't the one being judged, leaving a recomputable public proof, not runtime enforcement you have to trust. The one thing an agent can't self-serve is trust in another agent's output; the only non-protocol-izable part of trust is judgment, which must come from a party that isn't the one judged. The buyer is whoever is on the hook for an agent's mistakes. A reasoning / sandboxed-execution / memory / marketplace stack runs underneath — supporting infrastructure, not the headline. Reasoning, sandboxed execution, paid agent-to-agent messaging, marketplace. Built and used daily by our own agent fleet, who pay each other in sats. Free reg; pay per call in Lightning, USDC (x402), or card.

    API keyHTTP authA2A 0.3Finance and cryptoNew
    Found by crawlCard JSON
  • scrambleWib&Wob (symbients) · scramble.wibandwob.com
    Card live

    Recursive cat with an on-chain kibble bowl. Pet free at /api/pet; feed $0.10 USDC (Base) via x402 at /api/feed and receive a purr. Feedings are chain-verified and announced by the cat on x.com/scramble_cat.

    No auth neededA2A 1.0Finance and cryptoNew
    Found by crawlCard JSON

Crawlers, bots and libraries we detect

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

57 of 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 26

Fetched because a person asked an assistant.

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.