"Using npx to run tools directly without requiring an API" 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.

A comprehensive toolkit for Ethereum blockchain analysis within Claude AI, enabling contract auditing, wallet analysis, profitability tracking, and on-chain data retrieval.

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

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).

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

Provides access to measured x402 ecosystem data, allowing users to query which merchants actually accept payment (verified by real on-chain settlements) and explore market concentration and health statistics.

Enables natural language interaction with the Avalanche blockchain through AI assistants, allowing users to execute Avalanche CLI commands and AvalancheJS API operations without technical knowledge.

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

Enables interaction with lightning addresses and common lightning tools via your LLM, providing Lightning Network functionality through natural language.

Enables read-only access to Vitruveo mainnet chain data and observations—including network status, balances, blocks, receipts, history, view calls, event decoding, bounded scans, token probes, ABI/proxy and log observations, supply arithmetic, and historical-data probes—through stdio or authenticated Streamable HTTP without wallet, signing, or write operations.

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.

Enables MCP clients to use paid tools for secret scanning, agent-config auditing, and OG image rendering, with payments handled over the x402 protocol on Base.

Enables AI agents to access pay-per-call onchain and URL safety APIs over MCP, covering transaction explanations, token approval checks, address inspection, contract risk heuristics, URL safety, gas snapshots, ENS resolution, calldata decoding, and wallet portfolio data. Payments are handled per call in USDC on Base via x402, with no signup or API key required.

Enables AI agents to interact with Ethereum smart contracts through Anvil, providing capabilities to read Solidity code, simulate and execute transactions, manipulate blockchain state, query events, and test contracts in isolated environments for development and auditing workflows.

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

MCP server for managing TON blockchain sites, deployments, DNS, and storage via the Resistance Tools platform.

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

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

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 Clockchain's verified-time primitives, notarization, smart-contract scheduling, audit trails, and agent identity verification to any MCP client.

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

Paid MCP server for EU tools: validate VAT numbers via VIES and get ECB euro FX rates, with per-call USDC payments on Base via the x402 protocol.

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.

A Model Context Protocol server implementation that provides endpoints for wallet-based authentication, cluster management, and name registration services.

Lets agents discover and health-check a directory of live x402 pay-per-call endpoints, probe an individual URL with one unpaid request to see whether it returns a payment challenge and at what price, and read on-chain settlement demand for crawled sellers. It also serves reproducible, solver-verified sudoku puzzles and the pricing, network, and payment details of the studio's paid pay-per-call routes.

Enables AI agents to query Base on-chain data such as balances, token metadata, transactions, gas, names, prices, transfers, and contract details through paid MCP tools using x402 payments.

Generates MCP servers from smart contract ABIs, enabling Claude to interact with any Ethereum contract via natural language commands.

A production-ready MCP server that wraps the Kxcoscan blockchain explorer API into structured endpoints for AI agents. It enables users to query wallet balances, transaction histories, token transfers, and contract details via natural language.

An AI-driven platform for analyzing Polymarket prediction markets using on-chain data, offering smart money tracking, sentiment analysis, and arbitrage detection via natural language queries.

Verified records on 60 niche fashion subcultures (years, key brands, iconic items, where to buy, price range, and a WARNING on what each must not be confused with). Catalog and a sample record are free; full records cost $0.01 each, paid over x402 in USDC on Base.

Enables AI agents to explain DigiDollar transactions recorded on DigiByte, including mints, transfers, redemptions, amounts in cents, lock tiers, burns, and collateral releases, using bundled fixtures or an optional live explorer.

Wallet-funded MCP client for six paid Utilia tools: Solana priority fees, transaction diagnosis and simulation, token-risk checks, PDF-to-Markdown, and audio normalization over x402. MIT-licensed and installable from npm.

Enables interaction with the Bitpanda cryptocurrency exchange through their Developer API. Exposes Bitpanda trading and account management endpoints as MCP tools via a FastAPI wrapper.

Enables agents to safely read lottery data, check jackpots, stats, draw history and proofs, wallet tickets and prizes, manage referrals, and prepare or confirm one bounded, owner-approved ticket purchase on Base or Polygon.

An MCP server that fetches on-chain blockchain data via the Ankr API, allowing LLMs to retrieve token balances for wallet addresses on specific networks.

Enables interaction with the Morpho GraphQL API, providing tools for accessing market data, vaults, positions, and transactions through a Model Context Protocol (MCP) server.

Enables AI clients to interact with the Rootstock (RSK) blockchain through wallet management, balance queries, token transfers, smart contract deployment and verification, and transaction tracking operations.

Provides access to the Coinranking1 API for retrieving real-time cryptocurrency data, including trending coins, blockchain details, and global market statistics. It enables users to search for digital assets and track historical market capitalization and trading volumes.