"Papers With Code" matching MCP connectors:

~Alter is the identity layer agents query before they transact, answering who is actually on the other end. 11 of the 42 tools work with no account and no key. Call them now and see what comes back. Two calls plus a small proof of work gives your agent its own ~handle. Reads settle in USDC over x402 and 75% goes to the person read. Being known.

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.

Live multi-asset market data for AI agents with provenance, starter credits, x402, and examples.

SEC/XBRL issuer intelligence for crypto public companies via MCP, OpenAPI, x402, and MPP.

Teardrop is the native economic layer for AI agents, providing a robust suite of tools for multi-chain portfolio tracking, DeFi yield analysis, and gas estimation. It enables autonomous agents to securely find Web3 data and manage micro-payments on-chain with zero human intervention.

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.

Authorize x402 payments before signing with request-bound, signed safety decisions.

Universal pay-per-call tool API for AI agents. Web search, price feeds, hive memory, LLM routing, code sandbox. Free tier (10 calls/day, no signup). x402 payments on Base + Solana.

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.

Evidence-backed crypto due diligence with sources, freshness, and a runtime receipt on every call.

Solana token risk-scoring MCP server for AI trading agents with insider wallet cluster detection.

Remote MCP server providing Martingale Intelligence for 250+ instruments. Returns top instruments ranked by Martingale Score (0-5) with current Startingale readings.

Real-time curated crypto news for AI agents with sentiment, recaps, and search.

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

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

Receipt-backed Base Sepolia commerce with standing mandates and independent outcome verification.

Buy travel eSIMs, gift cards and mobile top-ups with crypto — user confirms before any order.

Discover privacy-first, bounded Venice-powered micro-work calls with exact x402 USDC prices.

Crypto data for AI agents via x402. 31 tools, 4 free. Recorded history, anchored daily on Base.

Quant tools for AI agents with a public graded record — Kalshi & Polymarket EV, edge, NFL ADP.