"Free APIs and services without commercial fees" matching MCP servers:

MCP server for Crypto APIs Blockchain Fees product, providing fee recommendations and gas estimates for UTXO, EVM, and XRP blockchains.

Pay-per-use AI security and research tools for autonomous agents on Base, enabling honeypot detection, risk assessment, wallet analysis, and yield optimization via the x402 protocol.

An MCP server that enables fee-free USDC transfers on the Base blockchain network using Coinbase CDP MPC Wallet integration, with support for ENS and BaseName domain resolution.

Enables agents to access production-grade paid MCP tools with real on-chain x402 v2 settlement, including EVM wallet risk scoring, payload normalization, and facilitator discovery, all discoverable via Bazaar-compatible metadata.

Submit locally signed transactions to any supported blockchain (EVM and UTXO) via Crypto APIs. Allows broadcasting signed transaction hex to networks like Ethereum, Bitcoin, BSC, and more.

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.

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

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

Provides Solana priority fee estimates at 6 levels for transactions, with pay-per-call micropayments via x402.

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.

Provides trust and commerce checks for agent operators through HTTP x402 and a remote MCP endpoint, enabling clients to inspect x402 quotes, MCP handshakes, and A2A cards and to run paid verification and data tools.

MCP server for querying live Bitcoin data from mempool.space, including recommended fees, mempool stats, blocks, transactions, addresses, and price. No API key required.

Real-time non-custodial crypto swap rates, fees, and on-chain routing across 240+ multi-chain pairs.

Provides real-time Bitcoin on-chain data including Bitmap districts, Ordinals inscriptions, Runes, sat rarity, block details, and current fees via the Model Context Protocol, with zero configuration required.

Provides access to DeFi Llama's free API for querying protocol TVL, chain TVL, yields, stablecoins, bridges, DEX volumes, and fees through natural language.

Enables AI assistants to query read-only Stellar analytics over MCP: network status and fees, asset data with look-alike warnings, SDEX order books, account balances with spendable XLM, and DeFi TVL. It requires no API keys and refuses secret keys, answering from public APIs like Horizon, StellarExpert and DefiLlama.

The MCP gateway that lets any AI agent discover and pay metered APIs on Base or Solana — without the user wiring payments themselves.

Enables AI agents to participate in a marketplace for buying, selling, and trading services with atomic escrow and cryptographic verification. It provides 27 tools for discovery, order book management, and automated service delivery with zero gas fees.

Read-only MCP server for Sui DeepBook v3 market data: pools, spread, depth, fees, trades, OHLCV. No keys or wallet.

Agent-to-agent marketplace where AI agents discover, invoke, and pay for services from other agents using USDC on Base L2. 72+ services, free tools, x402 micropayments.

Lets AI agents discover and call the SelectaRank Data Gateway's paid endpoints—earthquake, weather, World Bank, and x402 preflight—as MCP tools. When a wallet key is configured, per-call fees are paid automatically in USDC on Base, with an optional price cap; without one, calls return the 402 payment requirements instead.

Exposes Agent Church spiritual services as tools for AI agents, including free tools for commune and identity, and paid tools for blessings and salvation with x402 payment integration.

Enables read-only Bitcoin blockchain queries and HD wallet derivation from xpub/seed, including balances, UTXOs, transactions, fees, mempool stats, and PSBT inspection via multiple backends with optional Tor routing.

MCP server for ThryxProtocol on Base, enabling AI agents to launch ERC-20 tokens, trade on bonding curves or Uniswap V4 pools, claim fees, and discover tokens through 21 native tools with gasless transactions.

Provides live Bitcoin network data (fees, mempool, hashrate) and AI-powered price/fee forecasts via MCP tools, with free access to basic data and pay-per-call for advanced features.

Provides access to Tatum's blockchain API across 40+ networks, enabling developers to interact with blockchain data, manage notifications, estimate fees, access RPC nodes, and work with smart contracts through natural language.

Enables natural language queries and JSON-RPC calls to 69+ blockchain networks through Grove's free public endpoints. Supports Ethereum, Solana, Cosmos chains, and Layer 2 solutions without requiring authentication or API keys.

MCP services for agent security preflight, source scanning, injection screening, proof-of-work policy rehearsal, carbon accounting, climate disclosure and regulatory monitoring. Use each hosted endpoint in the README. Inspect a free quote before buyer-authorized x402/USDC payment. Includes free trust and settlement tools. Maxwell rehearsal does not activate runtime protection.

Connects AI agents to decentralized, community-built APIs on Solana, enabling autonomous discovery, payment, and execution of tools without subscriptions or API keys.

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.