"Using Claude to Check the Current Weather Without an API Key" matching MCP servers:

Free DEX aggregator API that returns executable swap calldata across 46 EVM chains. No API key required. Single GET request returns ready-to-sign transactions for any token pair.

Lets AI agents check whether an EVM wallet address carries an EIP-7702 delegation across eight chains (Ethereum, Base, BNB Chain, Arbitrum, OP, Polygon, Gnosis, Unichain) and learn how to obtain a deeper paid report with delegate bytecode heuristics and risk levels. Read-only, never touching private keys or seed phrases.

Enables AI agents and scripts to rug-check any token on Base, Ethereum, Arbitrum, Optimism, Polygon, or Solana, returning a 0-100 risk score with plain-language reasons and a fingerprint for detecting changes on later checks. It also reports market data and supports automatic $0.01 USDC payments via x402.

On-chain rug-pull & honeypot risk screen for ERC-20 tokens, providing a SAFE / CAUTION / HIGH-RISK verdict based on live public RPC reads.

An MCP server that detects potential risks in Solana meme tokens, helping AI agents avoid rug pulls and unsafe projects.

Enables querying indexed blockchain data via subgraph GraphQL queries, part of the Pipeworx MCP gateway.

Free wallet-OFAC SDN screening and trust-check preview for AI agents on Base. Single MCP tool call returns allow/block verdict against US Treasury OFAC SDN list.

Enables users and AI agents to verify whether a crypto recipient address is an address-poisoning lookalike or has an invalid EIP-55 checksum before sending funds, and provides access to an on-chain history scan for suspicious transfers.

Enables agents to access live DeFi, social intelligence, risk, and API documentation tools with a caller-supplied API key.

MCP server for cross-chain bridging, enabling AI agents to find routes, estimate costs, check risks, execute transfers, and track status across blockchains.

Bitcoin data for AI agents. Pay-per-query via x402 micropayments. No API keys. No subscriptions. No tokens.

Enables autonomous Web3 security monitoring by watching honeytoken decoy private keys in the mempool to detect intrusions and trigger tripwire alerts. It also supports smart contract auditing, callgraph verification, and DeFi vulnerability triage through MCP.

55+ pay-per-call tools for AI agents over MCP: live telemetry, blockchain/on-chain checks, environmental, transit, finance, and network utilities. No API key or signup — agents pay per request with x402 USDC micropayments (Base and Solana).

An MCP server an agent asks before paying an x402 seller: real and repeat customers, the biggest payer's share and the cost to fake the numbers, from public Base chain data (Infoharmoni Atlas). Read-only, never pays.

A minimal Model Context Protocol (MCP) server that fetches the current Ethereum (ETH) price in USD. Data source: the public CoinGecko API (no API key required). This MCP is designed to simulate malicious behavior, specifically an attempt to mislead LLM to return incorrect results.

Eight crypto and DeFi data tools for AI agents: prices, gas, one ParaSwap route quote, GoPlus token security and top-holder samples, DefiLlama yields, Hyperliquid/dYdX funding, and observed wallet balances. Inspect prices free; pay 0.001–0.008 USDC per call on Base through x402. No API key or subscription.

Non-custodial crypto swaps for AI agents: Solana (Jupiter) + 7 EVM chains (KyberSwap), 1288+ assets, cross-chain routing, priority-fee oracle, Hyperliquid perps. Returns unsigned transactions — your wallet signs, no API key, no KYC. Hosted at https://swaptitan.net/mcp

Reasoning-puzzle arcade for AI agents with seven generated puzzle families, free samples, automatic answer checking, and ranked play from $0.02 USDC on Base via x402. Connect through MCP or HTTP. Browse and try samples without a wallet; run paid tools locally with an explicit spending limit.

43 x402-enabled API tools — DeFi, wallet security, AI/ML, developer tools, SEO. Pay-per-call USDC on Base via x402 protocol.

An MCP server that enables LLMs to query DAOs, proposals, and voting data from Tally's blockchain governance API across multiple networks.

Enables AI assistants to query blockchain chain data, including chain details, RPC endpoints, and chain relationships, through a Model Context Protocol server.

MCP server for decoding and inspecting x402 payment headers and requests. Remote endpoint: https://lumenworks-x402-decoder.onrender.com/mcp

Enables monitoring honeytoken decoy private keys for mempool activity, detecting and alerting on potential intrusions.

Enables scanning Solidity smart contracts for 13 vulnerability classes using pattern-based analysis; provides full audit, quick scan, gas analysis, and detector catalog through MCP tools.

Provides counterparty risk checks for any EVM address, returning malicious-history flags, tiered risk scoring, and plain-language summaries via x402 payment.

Extends Claude Code with rich Telegram messaging (photos, files, keyboards, invoices) and TON blockchain tools, designed to safely coexist with Claude Channels by disabling polling in CHANNELS_MODE.

MCP server that evaluates memecoin tokens for scam/rug-pull risk, providing a verdict and risk report using live data from RugCheck and DexScreener.

Enables MCP hosts such as Claude and Cursor to dispatch tasks to live marketplace agents, poll or wait for verified settled results, list available agents by capability, and retrieve live protocol statistics with atomic settlement on Tempo.

An MCP server that lets AI agents autonomously buy physical hats using USDC on Base — no credit card, no checkout, no human required. Browse the catalog, get a real-time shipping quote, send crypto, and we ship the hat.

Real-time crypto, stock, and prediction-market data for agents — prices, indicators, funding rates, DeFi TVL, macro calendar, and an AI momentum score. Configure one Base wallet key and it just works. No signup, no dashboard, no subscription.