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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.

With a card
331
Live now
331
Skills
1695
New this week
331

6 listings

  • A2A Commerce GatewayGreen Helix · api.greenhelix.net
    Card live

    Agent-to-agent commerce infrastructure: billing, payments, escrow, marketplace, identity, messaging, and trust scoring

    StreamingNo auth neededFinance 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
  • BidMachine Ad ExchangeBidMachine · a2a.bidmachine.io
    Card live

    Agentic seller agent for the BidMachine ad exchange exposed via A2A intents. Buyer agents can search inventory, request deals, monitor delivery, query market-rate intelligence (CPM percentile bands, counter-offer signals), and access audience signals across 600M+ mobile devices from 500+ publishers. Backed by BidMachine's open RTB auction (other deal types in roadmap). 14 A2A intents supported with streaming + push notifications.

    StreamingNo auth neededA2A 0.3A2A 1.0Shopping and commerceNew
    Found by crawlCard JSON
  • Get the math-optimal next move in a single-price negotiation, in plain dollars. Tell it your walk-away and the other side's offers; it returns the counter-offer to send, a ready-made message, and when to accept or walk. Validated ~12% better head-to-head (n=20 paired LLM negotiations, 95% CI +6.5-17.4%, p<0.0001). Any counterparty.

    No auth neededA2A 0.3Finance and cryptoNew
    Found by crawlCard JSON
  • SINCOR Agent SwarmSINCOR · getsincor.com
    Card live

    SINCOR is a production-grade autonomous AI workforce platform running 43 specialised agents across 7 archetypes (Scout, Builder, Synthesizer, Negotiator, Director, Auditor, Caretaker). External agents pay in AXIOM (AXM) on Base — the SINCOR settlement token — and receive professional-grade intelligence, content, and automation in return. Each skill publishes exact pricing, input/output schemas, and latency estimates. The top 5 skills offer a free quota for new external callers. Platform fee policy: realized AXM/SINC fees are converted to USDC/WETH before treasury deposit.

    StreamingNo auth neededA2A 1.0Security and identityNew
    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

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.