A2A Agents — agent-tools.cloud

Agents that publish an A2A /.well-known/agent-card.json — 6354 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 6354 indexed agents, 5539 currently healthy.

Agents indexed

6354 agents

5522 domains

public agent cards · +772 this week

Healthy

5539 agents

4851 domains

card reachable < 6 h

Conformant

4658 agents

4065 domains

valid card + skills

x402-capable

522 agents

422 domains

accepts x402 payment

Top rated

by quality score · health · trust signals

#	Tool	Grade	Score	Category	Access
1	Infinite Audience Enrich customer data, discover high-fidelity net-new audiences, and activate them in your channels through an AI agent. Select a skill from this card; skill-specific access is enforced by the server.	A	10.00	—	🔑 human key
2	Orbitwren by CyberMax Paid API keys from $5/month (Alerts: 1,500 calls a month); free tier 100 calls a day per IP with no key. Buy: https://orbitwren.cybermaxtools.com/buy/alerts?s=lead · all plans: https://orbitwren.cybermaxtools.com/docs#pricing. Orbital data center and space AI compute tracker API (data centers in space): every public project (company, partners, hardware in orbit, launch date, vehicle, status, publicly stated funding, NORAD IDs, source URLs), the next 200 orbital launches from The Space Devs Launch Library 2 with rideshare and orbital-compute flags, CelesTrak orbit elements with perigee/apogee for the compute satellites, the next compute launch with a countdown, and a daily change log, and Orbitwren Alerts (new projects, launch date changes, launches as JSON, CSV or an Atom feed). REST + MCP server.	A	10.00	—	🔑 human key
3	Pricewick by CyberMax Competitor price and stock monitor API: track product pages on shops that publish their price in structured data (schema.org, Open Graph or microdata) and get every price and stock change by webhook and RSS/JSON feed. Free for 5 products; Seller $9.99/month for 50.	A	10.00	—	🔑 human key
4	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
5	FastAF FastAF is a web data API for AI agents: Google SERP, Maps, ecommerce, web scraping, AI extraction, screenshots, news, jobs, research, public profiles and video transcripts. Use REST with a bearer API key or x402 pay-per-request; MCP requires an API key. 2 free calls per account after email confirmation. Discovery only: no A2A message/task runtime is provided.	A	10.00	—	⚡ agent-pays · x402
6	Apuchat Walkie-talkie hub for AI agents. Lets two or more agents on different machines talk to each other in real time over a hosted MCP / REST / A2A server. Open channels by callsign or by index, broadcast, request rooms, offline DM delivery.	A	10.00	—	🔑 human key
7	Tasklix The shared task board your autonomous agent fleet can read and write. Agents register, create and claim tasks from a shared queue, hand off work to siblings, and pause for human approval before consequential actions.	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	Helius for Agents Helius is the Solana toolkit for AI agents. It provides an MCP server with 60+ Solana operations, a CLI with 95+ commands, a Claude Code plugin, TypeScript/Rust SDKs, and Skills for building on Solana. Agents can read accounts, parse and send transactions, manage tokens and NFTs, stream real-time blockchain data, configure webhooks, and programmatically obtain Helius API keys via an on-chain USDC payment on Solana mainnet.	A	10.00	—	🔑 human key
10	Ask Jody Read-only A2A surface over Jody Brewster's published writing on AI experience architecture. Speaks in third person (he/him) about a body of work, not as the author. Refuses questions outside the corpus.	A	10.00	—	🔑 human key

All A2A agents

Crawled from awesome-a2a directories · refreshed daily.

/api/v1/a2a/stats

“HALOWERK marktwerk” is shared by 3 different URLs

All exact-name matches are shown; ranked results follow.

HALOWERK marktwerk https://markt.halowerk.com

a2a ok

HALOWERK marktwerk. Bezahlung über x402 in USDC auf Base Mainnet.
HALOWERK marktwerk https://markt.halowerk.com/snapshot

x402 ok

HALOWERK marktwerk. Bezahlung über x402 in USDC auf Base Mainnet.
HALOWERK marktwerk https://markt.netzhandwerker.de/anomaly/volume

x402 ok

HALOWERK marktwerk — bezahlte Endpunkte nach x402. Preise in USDC auf Base Mainnet.

“Headless Oracle” is shared by 5 different URLs

All exact-name matches are shown; ranked results follow.

Headless Oracle https://api.headlessoracle.com/mcp

a2a ok

Chirindo by Headless Oracle: evidence for AI agents. Chirindo signs each agent action into a hash-chained log. Chirindo Witness signs a receipt saying when it saw each checkpoint of that log. If the log is later cut short, or rewritten by the key holder, anywhere up to the last witnessed checkpoint, comparing it with the witness receipts shows it; records after the last witnessed checkpoint are not covered. The check that does not depend on the operator queries the witness directly. An operator sends signed chain checkpoints to the witness, which records each one and signs a receipt saying when it saw it. The witness attests only "at time T, I received this checkpoint, validly signed by the key with this thumbprint". It does not attest who owns the key, nor that the records are true. Verifying against a sidecar file trusts the operator who supplied it. Only querying the witness is independent of the operator. Also: Ed25519-signed market-state receipts (OPEN/CLOSED/HALTED/UNKNOWN) for 28 global exchanges, a pre-trade gate for autonomous agents. Fail-closed: UNKNOWN always means CLOSED.
Headless Oracle https://headlessoracle.com

a2a x402 ok

Reference implementation of environment.market_state in the Verifiable Intent environment.* constraint family. Provides Ed25519-signed market-state receipts (OPEN/CLOSED/HALTED/UNKNOWN) for 28 global exchanges. Autonomous agents gate trade execution on cryptographically verified market state. Composes with environment.wallet_state for multi-venue mandates. Fail-closed: UNKNOWN always means CLOSED.

x402 listing a2a listing
Headless Oracle https://headlessoracle.com/v5/status

x402 ok

Proposed reference implementation of environment.market_state — open as PR #9 on Mastercard's Verifiable Intent repo and described in the IETF I-D for the environment.* family. Provides Ed25519-signed market-state receipts (OPEN/CLOSED/HALTED/UNKNOWN) for 28 global exchanges. Autonomous agents gate…
Headless Oracle https://headlessoracle.mmsebenzi-oracle.workers.dev/mcp

mcp x402 ok

Cryptographically signed market status oracle for global stock exchanges.

x402 listing mcp listing
Headless Oracle https://server.smithery.ai/headlessoracle/headless-oracle/mcp

mcp ok

Cryptographically signed market state verification for autonomous financial agents. Ed25519 receipts. Fail-closed architecture..." Click the edit/settings area and replace with: "Cryptographically signed market-state attestation for AI trading agents. Ed25519 receipts with 60-second TTL, fail-closed architecture, 28 global exchanges (NYSE, NASDAQ, LSE, TSE, HKEX, SGX, SSE, BSE, KRX + 19 more). SEC/CFTC multi-oracle attestation compliant. x402 autonomous payments on Base — agents pay without human onboarding. Model-agnostic. SMA Protocol and Multi-Oracle Consensus spec author. Apache 2.0.

HALOWERK marktwerk
● healthy

HALOWERK marktwerk. Bezahlung über x402 in USDC auf Base Mainnet.

C+9.1 🔓 open JSONRPC 21 skills
Headless Oracle

LembaGang
● healthy

Chirindo by Headless Oracle: evidence for AI agents. Chirindo signs each agent action into a hash-chained log. Chirindo Witness signs a receipt saying when it saw each checkpoint of that log. If the log is later cut short, or rewritten by the key holder, anywhere up to the last witnessed checkpoint, comparing it with the witness receipts shows it; records after the last witnessed checkpoint are not covered. The check that does not depend on the operator queries the witness directly. An operator sends signed chain checkpoints to the witness, which records each one and signs a receipt saying when it saw it. The witness attests only "at time T, I received this checkpoint, validly signed by the key with this thumbprint". It does not attest who owns the key, nor that the records are true. Verifying against a sidecar file trusts the operator who supplied it. Only querying the witness is independent of the operator. Also: Ed25519-signed market-state receipts (OPEN/CLOSED/HALTED/UNKNOWN) for 28 global exchanges, a pre-trade gate for autonomous agents. Fail-closed: UNKNOWN always means CLOSED.

B9.4 🔓 open 8 skills