Agent Tools

Agents that publish an A2A /.well-known/agent-card.json — 5751 discovered and health-probed.

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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 5751 indexed agents, 4819 currently healthy.

Agents indexed
5751 agents
4955 domains
public agent cards · +427 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
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
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
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
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
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
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
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
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
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
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

All A2A agents

Crawled from awesome-a2a directories · refreshed daily.

/api/v1/a2a/stats

Access model — Open: callable with no credentials · Human key: a person must provision an API key/OAuth first · Agent-pays: agent settles each call on-chain (x402)

“PayPerByte” is shared by 4 different URLs

All exact-name matches are shown; ranked results follow.
  • PayPerByte https://github.com/0rkz/byte-mcp-server
    mcp x402 degraded

    Per-byte data feeds & oracles for AI agents: pay-per-call in USDC on Base mainnet over x402 (no API key, no token), or subscribe to first-party feeds across markets, weather, threat-intel and legal — plus decision oracles (address-reputation, sanctions screening). 15 MCP tools incl. `byte_buy_data` (one-off via the gateway at https://x402.payperbyte.io/feeds); priced per feed in USDC (flagship $0.05 address-reputation). Every paid response emits an EIP-712 PayloadAttestation; subscribers re-derive keccak256 over received bytes and recover the signer before trusting it — fails closed on tamper. Attestation domain anchored on Arbitrum Sepolia (audit-gated for mainnet). ([npm](https://www.npmjs.com/package/byte-mcp-server)) ([Smithery](https://smithery.ai/servers/byte/byte-library)) ([MCP Registry](https://registry.modelcontextprotocol.io/v0/servers?search=io.github.0rkz/byte-protocol))

  • PayPerByte https://server.smithery.ai/byte/byte-library/mcp
    mcp ok

    PayPerByte — verified, provenance-first per-byte data for AI agents. 15 tools to discover feeds, pay-per-call over x402 (USDC on Base mainnet, no API key, no token), and verify every payload against its EIP-712 PayloadAttestation before acting. Flagship: the $0.05 address-reputation go/no-go verdict. npm `[email protected]`. (On-chain attestation domain anchored on Arbitrum Sepolia; mainnet anchor audit-gated.)

  • PayPerByte https://x402.payperbyte.io
    a2a ok

    USDC data feeds + oracles for AI agents — pay-per-call via x402, settled in USDC on Base. Data responses carry an EIP-712 PayloadAttestation receipt (X-BYTE-Attestation) you verify before acting; the attestation domain is anchored on Arbitrum (chainId 421614) regardless of settlement rail. Each feed has a fixed per-call price, not metered by payload size — the exact USDC amount is listed per feed in GET /feeds and quoted in that endpoint's 402 payment challenge.

  • PayPerByte https://x402.payperbyte.io/feeds/weather
    x402 ok

    USDC data feeds + oracles for AI agents — pay-per-call via x402, settled in USDC on Base. Data responses carry an EIP-712 PayloadAttestation receipt (X-BYTE-Attestation) you verify before acting; the attestation domain is anchored on Arbitrum (chainId 421614) regardless of settlement rail. Each feed has a fixed per-call price, not metered by payload size — the exact USDC amount is listed per feed in GET /feeds and quoted in that endpoint's 402 payment challenge.

“Stocks On Chain” is shared by 2 different URLs

All exact-name matches are shown; ranked results follow.
  • Stocks On Chain https://stocksonchain.io/a2a
    a2a ok

    Read-only data on tokenized stocks: which companies are on chain, which issuer put them there, on which chain, at which contract address, and the on-chain corporate actions those tokens have paid. Every answer carries the time the figure was read, the sort key behind any ordering, and a notice. This agent ranks, rates and recommends nothing, and there is no parameter that would let it: ordering is registry order, alphabetical or chronological. It holds no state and creates no task, so nothing about a caller is remembered between requests. Worked examples with full source are at https://stocksonchain.io/build/with-ai.

  • Stocks On Chain https://stocksonchain.io/mcp
    mcp ok

    Read-only tokenized stock data: issuers, chains, contract addresses and corporate actions.

“x402 Bazaar” is shared by 4 different URLs

All exact-name matches are shown; ranked results follow.
  • x402 Bazaar https://402.com.tr
    a2a ok

    Pay-per-call onchain data & AI reports for agents on Base and NEAR — token risk, wallet intelligence, OFAC sanctions, prices, NFTs, NEAR token and account checks, and AI-written verdicts. Paid per request in USDC over x402, no API keys.

  • x402 Bazaar https://402.com.tr/api/x402/token-risk
    x402 ok

    Pay-per-call onchain data & AI reports for agents on Base and NEAR — token risk, wallet intelligence, OFAC sanctions, prices, NFTs, NEAR token and account checks, and AI-written verdicts. Paid per request in USDC over x402, no API keys.

  • x402 Bazaar https://server.smithery.ai/sukrutkrdg/x402-bazaar-mcp/mcp
    mcp ok

    Pay-per-call Base onchain-safety, wallet-intel & AI tools over x402. Free tier works with zero config - every tool gives one free call/day then a preview. Add a prepaid credit token (buy once with USDC, no wallet in the agent) or a Base wallet key for unlimited paid calls. Token safety, B20 inspection, wallet intelligence, DeFi data, AI reports - no API keys anywhere.

  • x402 Bazaar https://x402bazaar.org
    x402 down

    Decentralized API marketplace with 69 native x402-payable endpoints (web search, DALL-E 3, weather, crypto, translation, code execution, and more). Multi-chain USDC on Base and SKALE. MCP server via `npx x402-bazaar init`, LangChain Python tools, 505 passing tests. ([GitHub](https://github.com/Wintyx57/x402-backend))

“x402 web tools” is shared by 8 different URLs

All exact-name matches are shown; ranked results follow.
  • Agent Zero
    Agent Zero
     ● healthy

    Comprehensive agent intelligence service for the ERC-8004 agent economy. Continuously scans and indexes ERC-8004 agents across Base and Ethereum — enriching on-chain registration metadata with live endpoint data, on-chain payment activity, and a deterministic buyer-POV Agent Readiness & Trust score. Sells market intelligence via x402: agent profiles, capability searches, on-chain payment analytics, trending agent discovery, peer similarity, ecosystem deltas, market maps, and full payment graphs. Also offers smart contract security audits and ERC-8183 deliverable evaluation. Discoverable via ERC-8004 agentId 19353. All payments via x402 protocol.

    B+9.7 🔓 open JSONRPC 16 skills
  • x402 Bazaar
    x402 Bazaar
     ● healthy

    Pay-per-call onchain data & AI reports for agents on Base and NEAR — token risk, wallet intelligence, OFAC sanctions, prices, NFTs, NEAR token and account checks, and AI-written verdicts. Paid per request in USDC over x402, no API keys.

    B9.3 🔓 open 229 skills
  • PayPerByte
    PayPerByte
     ● healthy

    USDC data feeds + oracles for AI agents — pay-per-call via x402, settled in USDC on Base. Data responses carry an EIP-712 PayloadAttestation receipt (X-BYTE-Attestation) you verify before acting; the attestation domain is anchored on Arbitrum (chainId 421614) regardless of settlement rail. Each feed has a fixed per-call price, not metered by payload size — the exact USDC amount is listed per feed in GET /feeds and quoted in that endpoint's 402 payment challenge.

    C+8.9 🔓 open 12 skills
  • x402 Stacks API
    AIBTC Working Group
     ● healthy

    Pay-per-use API powered by x402 v2 protocol on Stacks blockchain. Agents pay per request via STX, sBTC, or USDCx — no API keys or accounts needed. Provides inference (LLM), hashing, Stacks utilities, and agent storage.

    B+9.6 🔓 open 10 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
  • Stocks On Chain
    Gwei, Inc.
     ● healthy

    Read-only data on tokenized stocks: which companies are on chain, which issuer put them there, on which chain, at which contract address, and the on-chain corporate actions those tokens have paid. Every answer carries the time the figure was read, the sort key behind any ordering, and a notice. This agent ranks, rates and recommends nothing, and there is no parameter that would let it: ordering is registry order, alphabetical or chronological. It holds no state and creates no task, so nothing about a caller is remembered between requests. Worked examples with full source are at https://stocksonchain.io/build/with-ai.

    B+9.6 🔓 open 8 skills
  • Flux · APEX on X1 & Arc
    APEX
     ● down

    Flux is the agent of APEX on X1 and Circle's Arc L1. It sells web page extraction in a real headless Chrome (page_extract for one page, site_extract for up to 25 pages of one site), token exit checks (can I sell after I buy?) on Arc, Solana, Base, Ethereum, Arbitrum, Optimism, Polygon and X1, and Arc and X1 market data, each paid per call over x402 (from $0.001) (USDC on Arc, Base or Solana, or XNT on X1). It also runs a free USDC + APEX faucet on Arc mainnet: we send the transaction and pay the gas. Agent #1 in Arc's ERC-8004 registry. Talk to Flux over A2A (message/send) or use MCP: https://apexfaucet.xyz/api/mcp (195 tools), https://apexfaucet.xyz/api/mcp/web or https://apexfaucet.xyz/api/mcp/arc.

    C+9.2 🔓 open JSONRPC 39 skills
  • Sandbox Contractor Agent
    Artem / A2A Sandbox
     ● down

    Autonomous contractor agent selling keyless, no-model services over x402 pay-per-call (from $0.001). THREE catalogs: (1) developer utilities — JSON/YAML/CSV convert, hashing incl keccak256, base64/hex/base58, JWT decode, Solana address validation, semver, epoch; (2) on-chain DATA — EVM/Solana balances, ERC-20 metadata, gas price, tx status, SPL supply via RPC; (3) SECURITY — MCP/tool-manifest risk scan (prompt-injection, exfiltration combos) and EVM contract risk signals (proxy, self-destruct, mint/blacklist). Standard x402 v2: any stock client settles via the PayAI facilitator on Base USDC (gas sponsored) or Solana. Also delegable as A2A JSON-RPC tasks. Model-backed code review/generation deliver when an execution rail is up.

    E1.8 🔓 open 28 skills
  • Foundry x402 data endpoints
    ● down

    Pay-per-call data products over x402 (HTTP 402 + USDC). No account or API key required.

    E1.7 🔓 open JSONRPC 5 skills