This library provides a clean wrapper around all the methods exposed by a Polkadot/Substrate network client and defines all the types exposed by a node. For complete documentation around the classes, interfaces and their use, visit the documentation portal.

If you are an existing user, please be sure to track the CHANGELOG and UPGRADING guides when changing versions.

Looking for tutorials to get started? Look at examples for guides on how to use the API to make queries and submit transactions.

The API is split up into a number of internal packages -

• @polkadot/api The API library, providing both Promise and RxJS Observable-based interfaces. This is the main user-facing entry point.
• @polkadot/api-derive Derived results that are injected into the API, allowing for combinations of various query results (only used internally and exposed on the Api instances via api.derive.*)
• @polkadot/api-metadata Base extrinsic, storage and constant injectors for injection
• @polkadot/rpc-core Wrapper around all JSON-RPC methods exposed by a Polkadot network client
• @polkadot/rpc-provider Providers for connecting to nodes, including WebSockets and Http

Type definitions for interfaces as exposed by Polkadot & Substrate clients -

• @polkadot/types Codecs for all Polkadot and Substrate primitives