Check Crypto Address Balance Skill Query cryptocurrency address balances across multiple blockchains using free public APIs. Supports Bitcoin, Ethereum, BSC, Solana, Litecoin, and other major chains without requiring API keys for basic queries. Supported chains & best free APIs | Chain | API | Base URL | Rate limit | Notes | |-------|-----|----------|------------|-------| | Bitcoin (BTC) | Blockchain.info | | 1 req/10s | Most reliable, no key needed | | Bitcoin (BTC) | Blockstream | | Generous | Esplora API, open-source | | Ethereum (ETH) | Etherscan | | 5 req/sec (free) | Optional key for hi…