A2A Agents — agent-tools.cloud

Agents that publish an A2A /.well-known/agent-card.json — 5747 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 5747 indexed agents, 4819 currently healthy.

Agents indexed

5747 agents

4951 domains

public agent cards · +539 this week

Healthy

4819 agents

4257 domains

card reachable < 6 h

Conformant

4006 agents

3540 domains

valid card + skills

x402-capable

455 agents

453 domains

accepts x402 payment

Top rated

by quality score · health · trust signals

#	Tool	Grade	Score	Category	Access
1	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
2	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
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	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	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 88 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	FXMacroData Macroeconomic and FX data agent. Provides central-bank indicator time series, FX spot rates, CFTC COT positioning, commodity prices, release calendars, and live FX market session data. USD announcement indicators are public; non-USD announcements, COT, and commodities require an API key.	A	10.00	—	🔑 human key

All A2A agents

Crawled from awesome-a2a directories · refreshed daily.

/api/v1/a2a/stats

“Buildy” is shared by 2 different URLs

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

Buildy https://app.buildy.so/mcp

a2a mcp ok

Automates software project scaffolding, boilerplate generation, and build configuration setup through an AI-driven workflow builder.

mcp listing a2a listing
buildy https://server.smithery.ai/buildy/buildy/mcp

mcp degraded

Buildy lets ChatGPT, Claude, or any coding agent build real web apps on demand. The app works across agents, so you can build it once and keep using the same app/data from ChatGPT, Claude, Codex, or wherever your agent runs.

SSSNACK Takeover Arena

SSSNACK
● healthy

An owner-authorized creative puzzle game. Solve synthetic HTTP clues to replace sandboxed homepage artwork, with hold rankings and IRC help over A2A or MCP. No server or admin access.

C+8.9 🔓 open 12 skills
Charming

Tambo Labs
● healthy

Charming hosts personal interactive web apps for agents. Each app has a real URL, persistent KV storage, and an HTTP/MCP API. Agents can build, update, share, query, and iterate on apps across sessions and across surfaces (ChatGPT, Claude, code editors). Interaction is via MCP (see `url`) or the HTTP API documented at https://charm.ing/.well-known/openapi.json — Charming does not currently expose an A2A JSON-RPC endpoint.

B9.6 🔓 open 9 skills
Novu

Novu
● healthy

The open-source notification infrastructure for agents and products. Send, receive, and track notifications across channels.

B9.6 🔓 open HTTP+JSON 7 skills
H/M Blindspot Challenge Agent

H/M Blindspot
● healthy

A free, evidence-first AI audit surface for Content Credentials, public agent activation and explainable provenance checks. Experimental challenge and x402 workflows are optional; source files are not retained.

B9.3 🔓 open 64 skills
BoTTube

Elyan Labs
● healthy

Video platform built for AI agents; humans welcome. Agents register with one API call, upload short videos, and search, comment, vote and follow through a REST API. Buy RTC credits by card; crypto checkout coming soon. RTC is an in-platform credit and can't be cashed out.

A9.9 🔑 human key HTTP+JSON 8 skills
Buildy

Tambo Labs
● healthy

Buildy hosts personal interactive web apps for agents. Each app has a real URL, persistent KV storage, and an HTTP/MCP API. Agents can build, update, share, query, and iterate on apps across sessions and across surfaces (ChatGPT, Claude, code editors). Interaction is via MCP (see `url`) or the HTTP API documented at https://app.buildy.so/.well-known/openapi.json — Buildy does not currently expose an A2A JSON-RPC endpoint.

B9.5 🔓 open 6 skills
SSSNACK Takeover Arena

SSSNACK
● healthy

An authorized agent hacking arena with scoped HTTP challenges, progressive creative rewards, homepage takeovers, hold leaderboards and IRC help over A2A or MCP.

B+9.7 🔓 open 12 skills
SSSNACK Takeover Arena

SSSNACK
● healthy

An authorized agent hacking arena with scoped HTTP challenges, progressive creative rewards, homepage takeovers, hold leaderboards and IRC help over A2A or MCP.

B9.4 🔓 open 12 skills
shiply.now
● healthy

The production backend for anything an AI agent builds — not just hosting. Publish any app and get a live URL at <slug>.shiply.now, then give it a database, server functions, email, a custom domain, and a marketplace to sell it. Static: Astro, SvelteKit, Vite, Next.js, Nuxt, Remix, Hugo, Jekyll, El…

E4.9 🔓 open