Solana has released version 3 of its JavaScript SDK, @solana/web3.js, aimed at reducing bundle sizes and streamlining dependencies. The update rebuilds nine legacy classes using the Solana Kit toolkit, which was originally introduced in February 2025.
The new version introduces significant breaking changes, including a shift from synchronous to asynchronous methods and the requirement to use bigint for numeric values. Additionally, account data now utilizes the Uint8Array format for binary data.
The release includes a new wallet adapter package and provides support for Node.js 20.18 and above, modern browsers, and React Native. Version 3.0.0 was tagged on GitHub on October 1, followed by a maintenance release on October 5.
Version 1 of the SDK has been moved to maintenance-only status. Version 3.0.0 is expected to be marked as the default version on GitHub around October 19, 2026, which will automatically apply to new projects.
