Product update: Ethers V6 update for Sequence.js and Sequence Kit

At Sequence, we constantly push to ensure our tech stack is up to date, so developers can keep building seamless experiences on the Ethereum blockchain and its entire ecosystem.

Ethers.js is a comprehensive library designed for interacting with EVM blockchains. It is commonly utilized in dapps, wallets, and by individuals who wish to read from or write to blockchains manually.

Version 6 of Ethers.js was released in March 2023 and introduced numerous enhancements and changes compared to its predecessor.

To this end, we updated Sequence.js (TypeScript library) and Sequence Kit (UI integration library) from the existing Ethers V5 implementation to Ethers V6, which will be included in the 0xsequence package 2.x series release going forward.

Key differences between Ethers V5 and V6

Ethers' guide outlining differences between v5 and v6

Ethers.js V6 marks a significant evolution from v5, with a focus on modern JavaScript features and improved reliability. The transition from supporting ES3 targets to embracing ES6 has brought about several notable changes.

One of the most impactful updates is the replacement of the BigNumber class with JavaScript's native BigInt. This change simplifies operations by allowing the use of standard JavaScript operators, making the library faster and more straightforward. However, since BigInt only works with integers, the FixedNumber class is used for non-integer values.

Additionally, the Contract class in V6 is now an ES6 Proxy, enabling dynamic resolution of names and methods at runtime. This makes interacting with smart contracts more convenient and flexible. In V6, overloaded methods can be accessed directly through the TypeScript interface, although some methods previously available in the Contract scope now require a namespace to access.

These updates collectively enhance the performance and usability of Ethers.js, making it a more robust tool for interacting with EVM blockchains and the Ethereum ecosystem.

For complete information on the differences of Ethers v5 to V6 you can read more here in the official docs.

Main changes for developers transitioning to Ethers.js V6 with @0xsequence v2.0

Sequence's Ethers v6 Migration Guide

The @0xsequence package v2.0 now mandates a minimum Ethers.js version of [email protected]. If upgrading to Ethers.js V6 is not feasible, developers can opt to use @0xsequence v1.10.5 or @0xsequence/kit v3.0.0. In addition, if you are using Sequence Kit, then you will want to bump to v4.0.5 to maintain compatibility. 

For those transitioning from ethers@^5.0.0, here are the key changes to be aware of:

Static and default RPC provider

Connecting to a blockchain node and making RPC calls to query information has undergone changes in both static and default usage patterns. Developers should review the updated methods for establishing these connections.

BigNumber support

Ethers.js V6 introduces built-in support for ES2020 BigInt, which is available in modern JavaScript environments. This is particularly useful for generating randomly spaced token IDs, nonces, or other applications involving large string-based numbers.

Removal of Ethers utilities

The ethers.utils path has been deprecated. All references to utility functions should be updated to reflect the new structure, omitting the utils path.

Utility hash value packing

Signature creation and on-chain ecrecover usage have been slightly modified. Developers should familiarize themselves with the new methods for creating signatures and handling hash value packing

We have created a migration guide that details the most important information that you need to know to make sure you are ready when you decide to upgrade to the 2.0.0 release which will be supported going forward. Sequence has also a front-line support team in multiple time zones to help you with the migration.