Unified API Concepts
APIs that return enriched blockchain data applicable to all blockchain networks, eg: token balances, transactions, log events, etc
APIs maintained by Covalent for a specific protocol on a specific blockchain, eg: Constant Product AMMs (XY=K) on various blockchains.
APIs created and maintained by the community.
A Development Key can make requests at 4 RPS.
A Premium Key can make requests at 50 RPS.
Real-time and Batched APIs
Real-time APIs return responses closer to the head of the blockchain, while batched APIs are usually delayed by 30 mins.