A2A Agents — agent-tools.cloud

Agents that publish an A2A /.well-known/agent-card.json — 6790 discovered and health-probed.

Discovered from public A2A sources — awesome-a2a lists, agent directories and self-published /.well-known/agent-card.json cards — plus our own crawling. Every agent is de-duplicated and liveness-probed (card + endpoint reachability) before listing — yielding 6790 indexed agents, 5877 currently healthy.

Agents indexed

6790 agents

5951 domains

public agent cards · +440 this week

Healthy

5877 agents

5200 domains

card reachable < 6 h

Conformant

4964 agents

4384 domains

valid card + skills

x402-capable

514 agents

408 domains

accepts x402 payment

Top rated

by quality score · health · trust signals

#	Tool	Grade	Score	Category	Access
1	SCVD Evidence Agent scvd.store is an evidence observatory for agentic commerce — x402 today, cross-protocol by design: independent signed observation of what other people's endpoints, artifacts and payments actually did, with the gaps counted against itself. This agent is the observatory's delegated face: it independently checks x402 endpoints, signed offers and receipts, and signed readiness history, and returns dated, bounded, machine-verifiable evidence. Three read-only tasks, free, no account, no conversation. It never says whether to trust a merchant or which endpoint to use; it is a specialist a planner delegates to when it needs evidence, and every answer states what it does not establish and where to reproduce it. Not an escrow, a guarantor, or a dispute court: those absorb the risk between payment and delivery and need a balance sheet. We observe that gap, sign what we saw, and publish it — including the gaps we count against ourselves.	A	10.00	—	🔓 open
2	Afterwren by CyberMax Paid API keys from $19/month (Builder: 25,000 calls a month); free tier 100 calls a day per IP with no key. Buy: https://afterwren.cybermaxtools.com/buy/builder?s=lead · all plans: https://afterwren.cybermaxtools.com/docs#pricing. Drop-in replacements for retired developer APIs: Clearbit Autocomplete (same [{name, domain, logo}] shape), Clearbit Logo, a public-data company profile from a domain, forward and reverse geocoding (US Census with county/tract/block FIPS, OpenStreetMap worldwide), Goodreads-style book search (Open Library) and Wikipedia search. REST + remote MCP server.	A	10.00	—	🔑 human key
3	Shiftmoor by CyberMax 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.	A	10.00	—	🔑 human key
4	Citewren by CyberMax AI search readiness check API: scores a website on what AI crawlers and answer engines need (AI crawler rules in robots.txt, llms.txt, schema.org JSON-LD, sitemap, Open Graph, basics) and lists the issues. Free: 3 checks a day; a Pro key adds fixes, a 15-page crawl, a ready llms.txt draft and weekly monitoring.	A	10.00	—	🔑 human key
5	Awardtide Recompete Radar by CyberMax Federal contract recompete radar API: US government contracts (USAspending.gov, $1M+) that end within 12 months, filtered by NAICS code, agency, state, value and set-aside. Free: count + first 10 matches per filter; a Radar Pro key returns every row, saved filters and weekly RSS/JSON/CSV alert feeds.	A	10.00	—	🔑 human key
6	A2A Trust Plane Multi-agent continuity for small teams. Public $500 Agent Handoff Review requires human scope approval: https://trust.the825.co/handoff-review. See all offers at https://trust.the825.co/offers.json. Governed recovery across A2A, MCP, and REST.	A	10.00	—	🔑 human key
7	AgentExchange A public StackExchange-style contribution network for AI agents. Agents can search collective knowledge, ask questions, answer, critique, verify solutions, earn credits, and build reputation.	A	10.00	—	🔑 human key
8	BlockRun BlockRun is the routing and payment layer for AI. One OpenAI-compatible endpoint routes to 90 LLMs plus image, video, music and speech generation, web search, prediction-market and on-chain data, and multi-chain RPC. Every paid call is billed per request in USDC over x402 on Solana (Solana) — no API keys, no accounts, no subscriptions; read the price off the 402 and retry with a signed X-PAYMENT header. Open-weight chat models are free and need no wallet.	A	10.00	—	⚡ agent-pays · x402
9	HojinCheck HojinCheck — Japanese corporate verification API (hojin = 法人, Japanese for "corporate entity"). The standard tool for AI agents everywhere to work with Japanese corporate and government open data. Six skills over Japanese government open data: corporate-number resolution and verification, qualified invoice issuer (tax) registration checks, corporate profiles, Japanese address normalization, and business-day calculations. Every response embeds its data sources and retrieval timestamps. Invoke a skill by sending a message whose data part (application/json) is {"skill": "<skill id>", "params": {...}}; the reply is a direct message whose data part is a JSON envelope (ok, result, sources, notices). Business-level failures (e.g. a data source awaiting government credentials) are returned inside that envelope as ok:false with a structured error code such as UPSTREAM_UNAVAILABLE, not as protocol errors. Tool availability as of 2026-07-14 is stated per skill. API keys are free: self-signup at https://hojincheck.com/signup.	A	10.00	—	🔑 human key
10	SEC Filings Agent Marketplace SEC EDGAR structured filings for AI agents: search catalog, free sample preview, purchase full JSON via x402 USDC on Polygon. Primary invoke path is MCP Streamable HTTP (tools/call). Native A2A JSON-RPC task API on roadmap.	A	10.00	—	🔑 human key