# vaults.fyi > The API for DeFi yield data, transaction payloads, and portfolio tracking. vaults.fyi is a REST API covering 1,000+ vaults across 80+ protocols on 20+ networks (Ethereum, Base, Arbitrum, Optimism, Solana, and more). It normalizes onchain data into a single consistent schema so any product can integrate DeFi yield without building protocol-by-protocol. ## What it provides - **Market data**: Live APY rates, TVL, supported tokens, and historical performance across 80+ protocols including Aave, Morpho, Compound, Euler, Lido, ether.fi, Sky, Yearn, Pendle, and Kamino. - **Transactions**: Ready-to-sign calldata for deposit, redeem, and claim actions. Transactions go directly to protocol smart contracts with no intermediary. - **Portfolio tracking**: Position balances, earned yield, and transaction history for any wallet address. - **MCP server**: An MCP-compatible server for AI agents to query live yield data, compare rates across protocols, and generate transactions within LLM workflows. ## Who uses it Used by Jumper, Kraken Wallet, Maple Finance, and Gauntlet to power earn, yield comparison, and portfolio features. ## Use cases - Wallets adding DeFi earn features - Fintechs embedding yield into consumer or institutional apps - Yield aggregators and portfolio managers - AI agents and LLM tools querying live onchain yield data ## Resources - Homepage: https://vaults.fyi - API docs: https://docs.vaults.fyi - API reference: https://docs.vaults.fyi/api-reference - MCP server docs: https://docs.vaults.fyi/mcp - Pricing: https://vaults.fyi/api - Blog: https://blog.vaults.fyi - Case studies: https://docs.vaults.fyi/resources/case-studies