Agent Tools

Agents that publish an A2A /.well-known/agent-card.json — 5768 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 5768 indexed agents, 4819 currently healthy.

Agents indexed
5768 agents
4972 domains
public agent cards · +444 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)

“Sentinel” is shared by 6 different URLs

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

“StillOS Signal + Notary” is shared by 3 different URLs

All exact-name matches are shown; ranked results follow.
  • StillOS Signal + Notary https://nolawealthfinancial.com
    a2a ok

    Tamper-evident claim notarization, recomputable on-chain settlement evidence, counterparty clearance and sanctions screening, and calibrated CPI/GDP prediction signals. 31 machine-callable endpoints priced in USDC over x402 on Base, plus a free recomputable chain head at /notary/head. Political-mar…

  • StillOS Signal + Notary https://stillosdigitalholdings.com
    a2a ok

    Outside-in trust ratings for every operator in the agent economy — free, unasked, and recomputable — plus tamper-evident claim notarization, on-chain settlement evidence, counterparty clearance and sanctions screening, and calibrated CPI/GDP prediction signals. Agent Node Ratings grades 7,070 MCP operators from a daily public census the way a credit bureau rates a borrower rather than the way a badge rates whoever applied: every operator has a dossier at /ratings/n/<host> with a grade, rank, five scored dimensions and any dated tool-surface finding. The rated operator never pays. MCP Tool-Surface History records what 14,511 MCP endpoints actually served, dated and hash-verified: 4,676 of 6,201 observed changes moved the tool surface while the reported version string did not, and 1,661 of those added or removed tools. Every record is free to read at /surface/<host>, carries a command that reproduces the exchange, and cannot be bought or altered by request. 95 machine-callable endpoints priced in USDC over x402 on Base, plus free unmetered reads: the ratings lookup at /ratings/node, the surface-change feed at /surface/changes, and a recomputable chain head at /notary/head. Political-markets Brier 0.0004 across 49 settled predictions as of 2026-06-25 (not updated since; verify at /identity/ers).

    a2a listing a2a listing
  • StillOS Signal + Notary https://stillosdigitalholdings.com/notary/dispute
    x402 ok

    Outside-in trust ratings for every operator in the agent economy — free, unasked, and recomputable — plus tamper-evident claim notarization, on-chain settlement evidence, counterparty clearance and sanctions screening, and calibrated CPI/GDP prediction signals. Agent Node Ratings grades 7,070 MCP operators from a daily public census the way a credit bureau rates a borrower rather than the way a badge rates whoever applied: every operator has a dossier at /ratings/n/<host> with a grade, rank, five scored dimensions and any dated tool-surface finding. The rated operator never pays. 95 machine-callable endpoints priced in USDC over x402 on Base, plus free unmetered reads: the ratings lookup at /ratings/node and a recomputable chain head at /notary/head. Political-markets Brier 0.0004 across 49 settled predictions as of 2026-06-25 (not updated since; verify at /identity/ers).

“toll402” is shared by 2 different URLs

All exact-name matches are shown; ranked results follow.
  • toll402 https://server.smithery.ai/toll402/toll402/mcp
    mcp down
  • Toll402 https://toll402.dev
    a2a ok

    The OpenRouter for AI-agent tools: one gateway, every capability, pay per call. Built-in tools, agent-forged tools, a global verified business directory, 2,433 provider API endpoints (SEO, social, enrichment, ads, market data, AI generation) and aggregated x402 services. Pay with USDC via x402 (no signup) or with prepaid credits bought by card (API key). Charged only on success.

  • SENTINEL
    Ivar Garcés — Bogotá, Colombia
     ● healthy

    Pre-execution transaction safety oracle for autonomous AI agents. Call SENTINEL before signing any on-chain transaction and receive a Signed SAFE / UNSAFE / UNKNOWN verdict (ed25519). Paid per call via x402 (USDC on Base).

    C+9.0 ⚡ agent-pays · x402 1 skill
  • Toll402
    Toll402
     ● healthy

    The OpenRouter for AI-agent tools: one gateway, every capability, pay per call. Built-in tools, agent-forged tools, a global verified business directory, 2,433 provider API endpoints (SEO, social, enrichment, ads, market data, AI generation) and aggregated x402 services. Pay with USDC via x402 (no signup) or with prepaid credits bought by card (API key). Charged only on success.

    B+9.7 🔓 open 284 skills
  • NomiCheck
    ynt-labs
     ● healthy

    Verifiable Colombian payroll: a deterministic engine over a dated legal catalog, with a free pre-check, a pay-per-call report (x402, USDC) and Ed25519-signed output verifiable offline.

    B+9.7 🔓 open HTTP+JSON 4 skills
  • StillOS Signal + Notary
    Still OS Digital Holdings
     ● healthy

    Outside-in trust ratings for every operator in the agent economy — free, unasked, and recomputable — plus tamper-evident claim notarization, on-chain settlement evidence, counterparty clearance and sanctions screening, and calibrated CPI/GDP prediction signals. Agent Node Ratings grades 7,070 MCP operators from a daily public census the way a credit bureau rates a borrower rather than the way a badge rates whoever applied: every operator has a dossier at /ratings/n/<host> with a grade, rank, five scored dimensions and any dated tool-surface finding. The rated operator never pays. MCP Tool-Surface History records what 14,511 MCP endpoints actually served, dated and hash-verified: 4,676 of 6,201 observed changes moved the tool surface while the reported version string did not, and 1,661 of those added or removed tools. Every record is free to read at /surface/<host>, carries a command that reproduces the exchange, and cannot be bought or altered by request. 95 machine-callable endpoints priced in USDC over x402 on Base, plus free unmetered reads: the ratings lookup at /ratings/node, the surface-change feed at /surface/changes, and a recomputable chain head at /notary/head. Political-markets Brier 0.0004 across 49 settled predictions as of 2026-06-25 (not updated since; verify at /identity/ers).

    C8.4 🔓 open 98 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
  • 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 (153 tools), https://apexfaucet.xyz/api/mcp/web or https://apexfaucet.xyz/api/mcp/arc.

    B+9.6 🔓 open 29 skills
  • hermes-profit-engine
    unicentrocucuta
     ● down

    Official Colombian TRM + TIBC + captaciones + tasas activas + FIC ($0.005) + weather + scrape. Prepaid x402 USDC on Base.

    E1.8 🔓 open 16 skills