"Web search services that don't require 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.

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.

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

Enables AI agents and their users to retrieve scored news sentiment, narratives, historical readings, and cited sources for Bitcoin, gold, and oil, with tamper-evident, time-stamped data for trading decisions.

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.

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

Enables web search for AI agents with pay-per-search in USDC, no API keys needed.

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

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

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.

This MCP wraps Bitrefill public API to allow agents to search for products and shop using cryptocurrencies like Bitcoin, Ethereum, Solana, and many more.

Enables AI agents to evaluate stablecoin treasury allocations by protecting upcoming obligations, calculating true surplus, stress-testing proposed investments, and returning explainable ALLOCATE, HOLD, or BLOCK decisions.

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.

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.

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.