"Documentation URL for a service API, data, and LLM usage" matching MCP servers:

Cross-chain cryptocurrency swaps via Chainflip. Get quotes, execute swaps, and track progress. No API key required to get started.

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.

Monero/Zcash payment webhooks + DeFi liquidation & Ethereum builder data over MCP. Free tier; x402.

A Model Context Protocol service that enables agent authentication and integration with TrustGo platform, providing access to real-time data like price, sigma score, and mindshare bubble analytics.

A Model Context Protocol (MCP) server providing comprehensive access to the XRP Ledger (XRPL). This service enables AI models to interact with XRPL through standardized endpoints.

Enables AI agents to fetch live multi-chain portfolio, token info, gas prices, and token prices across Ethereum, Base, Polygon, Arbitrum, and Optimism with a single call. No API key required.

23 agent tools: DEX token prices, liquidity, slippage, gas and arbitrage across BNB Chain, Polygon, Arbitrum, Base, Avalanche and Optimism, plus geocoding, weather, web search, URL-to-Markdown, RSS, IP geolocation, holidays, GLEIF LEI lookup and the US Treasury yield curve. 22 are free with no API key, wallet or signup. One paid cross-DEX spread tool pays from your wallet, with hard spend caps.

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

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

A Node.js service that provides spot trading functionality through the LnExchange API.

MCP server providing real-time crypto prices (Chainlink + Binance), Polymarket prediction market data, deep web research, and JS-rendered web scraping. All services available via x402 Solana micropayments.

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.

Lets AI agents make automated USDC micro-payments on Base mainnet via x402/MPP to unlock clean structured data from URLs and other pay-per-call tools like Markdown reading, security scans, wallet enrichment, and settlement proof, with no API key or subscription.

Integrates multiple XRPL data sources including LOS, Validator History Service, XRPL JSON-RPC, and XRPLMeta to provide comprehensive querying of XRPL network data, accounts, transactions, tokens, validators, and more via MCP tools.

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 AI agents to fetch crypto market and on-chain data, including prices across venues, token facts, OHLC candles, market overview, DeFi TVL, and wallet balances, with two free tools and the rest paid per call in USDC on Base via x402.

Enables MCP-capable AI agents to access pay-per-call Solana data such as health, token prices, account balances, transactions, and trending DEX pairs, with automated x402 USDC settlement and no signup or API key required.

Enables MCP-capable AI agents to make pay-per-call Solana data requests (snapshots, risk checks, token reports, health, balances, transactions, trending pairs) with automatic USDC settlement over x402.