Polkadot is a multi-chain blockchain network that enables interoperability between specialized blockchains called parachains. Developer APIs are provided through Subscan (a multi-chain block explorer with a hosted HTTP API) and the Substrate API Sidecar (a REST interface for Polkadot SDK-based chains), enabling queries against extrinsics, events, accounts, blocks, staking data, and parachain state on Polkadot, Kusama, and related networks.
Subscan provides a hosted HTTP API for querying indexed on-chain data across more than 90 Substrate-based networks including Polkadot and Kusama. Endpoints cover blocks, extrinsics, events, accounts, staking, tokens, and parachain data.
The Substrate API Sidecar is an open-source REST service maintained by Parity Technologies that provides a RESTful interface for interacting with Polkadot SDK-based blockchains. It covers blocks, accounts, transactions, staking, and parachain/coretime data.
The Polkadot REST API is a Rust rewrite of the Substrate API Sidecar, maintained by Parity Technologies, offering REST endpoints for blocks, transactions, accounts, staking, and parachain/coretime data.