"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.

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

Enables AI agents to access 13 paid micro-tools over x402, paying per request in USDC on Base without API keys or signup. It covers email deliverability, grading, and templates, plus utilities like crypto prices, domain age, hashing, JSON conversion, JWT decoding, regex, slugs, UUIDs, and weather.

An unofficial, read-only MCP server for Sarwa Odyssey that provides portfolio, holdings, transactions, watchlists, and agent snapshots via deterministic JSON documents.

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.

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

MCP server for querying cryptocurrency portfolio data, transaction history, net worth, and historical snapshots across 20+ blockchains via the Octav API.

Trust layer for AI agents: 22 pay-per-call x402 tools for scam and fraud checks, payment pre-flight, wallet screening, policy approvals, contact extraction and company research. Free preview with no wallet; paid calls settle in USDC on Base.

Enables MCP clients to access exchange rates for 160+ currencies, currency conversion, historical rates, time series, crypto, metal and stock prices, usage checks, and rate alerts.

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

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 interactive access to TradeSearcher strategies and backtests via CLI and MCP, allowing agents to search, backtest, and compare trading strategies.

A collection of three zero-dependency MCP servers for web scraping via Chrome DevTools Protocol, crypto wallet and price monitoring, and email validation with SMTP sending.

Enables AI agents to fetch real-time trading signals and technical indicators for cryptocurrencies using Binance market data.

Enables AI agents to convert PDFs and images into validated, structured JSON for invoices, receipts, contracts, and resumes, or into any caller-supplied JSON Schema, through five extraction tools. Each tool call pays per use in USDC over x402 from a wallet the caller supplies, with no signup or API key required.

Enables MCP clients to read public web pages as clean markdown, verify whether a quote appears on a page, check the health of up to 25 links, and audit any origin's x402 and agent-readiness setup. Tools are pay-per-call in USDC on Base via x402 with free previews, requiring no signup or API key.

Provides 63 production-ready API tools for AI agents, including web scraping, AI generation, crypto data, OCR, image generation, audio transcription, text-to-speech, email, and domain lookup.

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.

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.

Enables AI agents to use pay-per-call web-to-Markdown, structured extraction, crawling, Base token and wallet data, FX rates, and crypto alert tools via USDC payments on Base.

pay-per-call x402 API endpoints as MCP tools — web search, page-to-markdown, PDF extract, JSON repair/validate, crypto price, weather, IP geo, DNS, markdown lint + 20 agent-commerce aliases. Each tool proxies to vibes-coded.com and settles via x402 (USDC/Solana). Free-trial endpoints need no auth; paid ones need an x402 signature. Catalog is fetched live, so new endpoints appear automatically.

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.

Connects Claude Desktop to crypto and brokerage portfolio data via Coinbase and SnapTrade, providing read-only tools to inspect accounts, holdings, prices, and provider health.

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.

Gives AI assistants access to real-time financial data including stock prices, crypto, forex, market sentiment, sector analysis, and company fundamentals via the Infoway API.

Python/stdio MCP connector providing timestamped crypto intelligence for ten assets: prediction-market intelligence, market regimes, sentiment, funding, liquidity, asset rankings, and component-score explanations. Public access without signup, API keys, or trial activation; no trade execution.

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.

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.

Enables read-only access to ROOTSTOCK DEX and Orchard data on Base and Base Sepolia through 34 stdio tools for querying networks, registries, pools, token balances, and transaction status.

Provides cryptocurrency news, prices, sentiment analysis, and market data through the Crypto News51 API.

Provides read-only crypto perpetual futures market data from Arbitron's tracked venues, including current funding rates, funding history, venue spreads, backtested spreads, and listings calendar, through MCP tools for AI assistants.

Enables AI agents to discover and call hundreds of x402-priced APIs on Base, including token safety checks, prediction-market odds, web/network/market data, and utilities, with a free cross-bazaar discovery search.

Real-time OFAC and global sanctions screening for AI agents: screen crypto addresses, emails, websites, government IDs, and countries against OFAC SDN and 10+ sanctions/crime/risk lists, plus PEP screening, VPN detection, and IP geolocation. Hosted remote streamable-HTTP server at https://api.compliapi.com/mcp (anonymous tools/list; free API key or x402 pay-per-call).

Provides access to NFTGo's Developer API for retrieving NFT collection details, asset information, market data, wallet information, and search capabilities on the Ethereum blockchain.

The Capital.com MCP Server lets your AI assistant talk to your trading account directly. Market data, position checks, trade previews – all in plain language, without leaving your AI tool.

Enables agents to screen Solana tokens, triage swaps before signing, and generate optimized unsigned swap transactions with payment and budget controls through MCP tools.