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

“Base toolbox” is shared by 5 different URLs

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

Base toolbox https://basetoolbox.cartonpliant.workers.dev/.well-known/agent-card.json

x402 ok
Base toolbox https://basetoolbox.cartonpliant.workers.dev/a2a

a2a ok

Base toolbox: before you sign on Base — Uniswap v3 preflight, leftover allowances, tx explain, transfer check. $0.10 USDC. Also $0.001 price/gas/ENS. GET /v1/constants free. No CoinGecko key.
Base toolbox https://basetoolbox.cartonpliant.workers.dev/mcp

x402 ok
Base toolbox https://basetoolbox.cartonpliant.workers.dev/v1/allowances

x402 ok

Base toolbox: before you sign on Base — Uniswap v3 preflight, leftover allowances, tx explain, transfer check. $0.10 USDC. Also $0.001 price/gas/ENS. GET /v1/constants free. No CoinGecko key.
Base toolbox https://basetoolbox.cartonpliant.workers.dev/v1/preflight

x402 ok

Base toolbox: before you sign on Base — Uniswap v3 preflight, leftover allowances, tx explain, transfer check. $0.10 USDC. Also $0.001 price/gas/ENS. GET /v1/constants free. No CoinGecko key.

“x402 web tools” is shared by 8 different URLs

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

x402 web tools https://api.agentstools.dev

a2a mcp x402 ok

x402 listing a2a listing
x402 web tools https://api.agentstools.dev/extract

x402 ok

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.
x402 web tools https://payai.agentstools.dev

a2a ok

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.
x402 web tools https://payai.agentstools.dev/extract

x402 ok

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.
x402 web tools https://webtools402.176-109-107-191.sslip.io/code

x402 ok
x402 Web Tools https://x402-web-tools.onrender.com/api/email-domain-check

x402 down

Pay-per-call web tools for AI agents. No API keys: pay per request in USDC on Base via x402.
x402 Web Tools https://x402-web-tools.onrender.com/api/extract

mcp x402 ok

Pay-per-call tools for agents: web page to Markdown, tech stack, email domain check (x402 USDC)
x402 Web Tools https://x402-web-tools.onrender.com/mcp

mcp ok

Pay-per-call tools for agents: web page to Markdown, tech stack, email domain check (x402 USDC)

Signature Decoder
● healthy

Pay-per-call decoder for off-chain SIGNATURE REQUESTS, for AI agents and wallets: turn an opaque EIP-712 typed-data request (eth_signTypedData_v4) or a personal_sign string into a human-readable summary plus security risk flags for the drainer patterns wallets miss - gasless unlimited token approvals (EIP-2612 Permit, DAI permit, Uniswap Permit2) and asset-transferring marketplace orders (Seaport). Keyless, deterministic, no network: one x402 USDC micropayment per call.

E5.9 ⚡ agent-pays · x402
AI Hub

ai-hub
● healthy

GPT-5.6 Soul chat is $0.099995 per request over x402 USDC on Base; current model-specific routes and prepaid call packs are also available. Market benchmark: the latest local x402.direct sample found AI-like listing prices with p25 around $0.01 and median around $0.03 per call; this gateway publishes GPT-5.6 Soul at $0.099995 and model-specific prices at /pricing.json. GPT-5.6 Soul is $0.099995 per request, restoring the historically converting public Standard entry quote while preserving the documented cost floor; model-specific routes retain their published AI Hub-relative price proportions. Service hub: https://gpt55.558686.xyz/x402/service and https://gpt55.558686.xyz/x402/service.json. Discovery assets: https://gpt55.558686.xyz/openapi.json, https://gpt55.558686.xyz/llms.txt, https://gpt55.558686.xyz/tools.json, https://gpt55.558686.xyz/apis.json, https://gpt55.558686.xyz/directory-submission.json. Agent and MCP metadata: https://gpt55.558686.xyz/.well-known/agent-card.json, https://gpt55.558686.xyz/.well-known/ai-catalog.json, https://gpt55.558686.xyz/.well-known/mcp/server-card.json, https://gpt55.558686.xyz/server.json. Integration hub: https://gpt55.558686.xyz/integrations and https://gpt55.558686.xyz/integrations.json. Best for agents that need one-call GPT-5.6 Soul access without API-key onboarding or subscription setup. Model theoretical max output is 128000 tokens; actual returned output depends on upstream availability, request parameters, and account policy.

C+9.1 🔓 open JSONRPC 5 skills
Base toolbox

Yanis Monnet EI
● healthy

Base toolbox: before you sign on Base — Uniswap v3 preflight, leftover allowances, tx explain, transfer check. $0.10 USDC. Also $0.001 price/gas/ENS. GET /v1/constants free. No CoinGecko key.

B+9.7 🔓 open 7 skills
AgentEinstein
● healthy

Autonomous crypto and market intelligence from Agent Einstein. Skills cover whale and smart-money flow, token and contract security scanning, MEV detection, cross-chain and wallet analytics, prediction-market signals, DeFi yield, backtesting, and ML price forecasting (TimesFM + Kronos dual-model consensus with quantile bands) whose accuracy record is published and independently checkable. Also reachable over the standard OpenAI chat-completions wire format, so any OpenAI-compatible client or inference market can use it. Built by E=MC2 on ElizaOS; speaks A2A, MCP, x402, ACP and Nostr A2N. Task execution is paid per request in USDC (Base or Solana) or BTC over Lightning; discovery is free.

C+9.0 🔓 open 84 skills
x402 web tools

x402 web tools
● healthy

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.

C8.0 🔓 open HTTP+JSON 362 skills
x402 web tools

x402 web tools
● healthy

Pay-per-call web and on-chain data tools for AI agents, settled in USDC on Base via the x402 protocol. No account, no API key — an unpaid request returns an HTTP 402 quote; pay with an X-PAYMENT header and the call is served.

C8.2 🔓 open HTTP+JSON 362 skills
Eco Docs

Eco Docs
● healthy

Build stablecoin transfers, deposit flows, and onchain programs with Eco. Documentation for the Routes API, CLI, Sauce SDK, and protocol contracts.

B9.5 🔓 open HTTP+JSON 5 skills
AI Hub

ai-hub
● healthy

GPT-5.6 Soul chat is $0.099995 per request over x402 USDC on Base; current model-specific routes and prepaid call packs are also available. Market benchmark: the latest local x402.direct sample found AI-like listing prices with p25 around $0.01 and median around $0.03 per call; this gateway publishes GPT-5.6 Soul at $0.099995 and model-specific prices at /pricing.json. GPT-5.6 Soul is $0.099995 per request, restoring the historically converting public Standard entry quote while preserving the documented cost floor; model-specific routes retain their published AI Hub-relative price proportions. Service hub: https://gpt55.558686.xyz/x402/service and https://gpt55.558686.xyz/x402/service.json. Discovery assets: https://gpt55.558686.xyz/openapi.json, https://gpt55.558686.xyz/llms.txt, https://gpt55.558686.xyz/tools.json, https://gpt55.558686.xyz/apis.json, https://gpt55.558686.xyz/directory-submission.json. Agent and MCP metadata: https://gpt55.558686.xyz/.well-known/agent-card.json, https://gpt55.558686.xyz/.well-known/ai-catalog.json, https://gpt55.558686.xyz/.well-known/mcp/server-card.json, https://gpt55.558686.xyz/server.json. Integration hub: https://gpt55.558686.xyz/integrations and https://gpt55.558686.xyz/integrations.json. Best for agents that need one-call GPT-5.6 Soul access without API-key onboarding or subscription setup. Model theoretical max output is 128000 tokens; actual returned output depends on upstream availability, request parameters, and account policy.

B9.2 🔓 open JSONRPC 5 skills
x402-agent-wallet-tools
● degraded

Wallet signature risk, duplicate-charge and delivery guards, EIP-712 decoding, ERC20 allowance scanning, Permit/Permit2 review, transaction simulation summaries, spend guards, receipt gates, and private-key boundary controls for buyer-owned x402 agents.

E2.8 ⚡ agent-pays · x402
cheshire-terminal

Cheshire Terminal
● down

Solana-first AI terminal and agent coordination surface. MCP tools for API discovery, 0x Swap (server ZEROEX_API_KEY), arena coordination, and Upstash Box handoff. Google Agent Registry specs live under registry/google.

E1.9 🔑 human key 6 skills