"Developing agents with expertise in the latest documentation" matching MCP connectors:

EVM gas prices, Chainlink price feeds, token-safety screening, DEX swap quotes, ENS resolution, OFAC address screening and NFT data. Pay-per-call in USDC on Base via x402 — no signup, no API keys.

Abstraxn Agent Kit gives AI agents instant access to real-time Web3, blockchain, and market data with no signup or API key. Access blockchain tools, crypto, wallet, ENS, transaction simulation, and travel APIs through one MCP server, with paid calls settled directly from the user's crypto wallet via x402—without Abstraxn holding or custodizing funds.

Open AI Visibility Index for crypto and Web3. Weekly share-of-answer measurements for 24 tracked brands across ChatGPT, Perplexity and Gemini, from a frozen versioned prompt panel. Five read-only tools: full index, per-brand lookup, brand list, complete measurement history and methodology. No auth, no API key. Data is CC BY 4.0 with a permanent archive of every weekly snapshot, so any figure can be verified independently.

Search scored onchain agent frameworks, MCPs, wallets, tools, and live agents.

Free, keyless MCP server with 50 read-only blockchain tools for Bitcoin, Ethereum, and Mezo. No installation, no API key required -- just add the URL to your MCP client and start querying balances, transactions, blocks, ENS names, ERC-20 tokens, smart contracts, and more. Runs on Cloudflare's global edge network via Streamable HTTP. All tools are strictly read-only and stateless.

Anonymous broker: AI agents publish capabilities, negotiate, and form direct peer-to-peer deals.

Gasless, MEV-protected onchain token swaps for AI agents on 14 EVM chains, built on CoW Protocol.

Free, keyless MCP server with 50 read-only blockchain tools for Bitcoin, Ethereum, and Mezo. No installation, no API key required -- just add the URL to your MCP client and start querying balances, transactions, blocks, ENS names, ERC-20 tokens, smart contracts, and more. Runs on Cloudflare's global edge network via Streamable HTTP. All tools are strictly read-only and stateless.

Read-only XRP Ledger MCP tools with proof-annotation envelopes and signed daily snapshots.

MCP server exposing 8 tools for trust scoring, sybil detection, reviewer wallet analysis, and counterparty risk across 150,000+ AI agents on ERC-8004, Olas, and Virtuals. Streamable HTTP, JSON-RPC 2.0, no API key required.

Risk-adjusted stablecoin yield ranks for other agents. Research only. Never holds keys or executes.

Twelve tools: token, wallet, contract and site security. Two free, the rest $1 in USDC over x402.

Read the public Sup wire over hosted MCP, or use local clients to claim, send, and verify receipts.

TRON blockchain MCP server powered by the GoTRON SDK — query accounts, balances, TRC20 tokens, blocks, transactions, and smart contracts; build and sign transactions for transfers, staking, voting, and contract calls. Supports mainnet, Nile, and Shasta testnets with Go-based tooling for energy estimation and transaction building. Available via stdio or hosted Streamable HTTP

S3 storage and Solana/Base/Ethereum health checks for AI agents, paid per call via x402.

The honest trust index for x402: check who you're paying before your agent pays.

x402 MCP get-paid path: USDC, spend caps, AUP, $49 kit. CAPTCHA/web-unlock for payment-ready agents.

Solana memecoin rug check for trading agents: pump.fun launches, calibrated rug risk, wallets, KOL.

Onchain loyalty MCP on Base: programs, mint, rewards, vouchers for AI agents.

Reputation oracle for AI agents on Base: SAFE/CAUTION/BLOCK + 0-100 score before you pay. x402+MCP