# What changed in viem

> 15 changes in viem 2 from its official release notes, upgrade guides and advisories: 2 breaking, 1 security, 5 new APIs and options. Each one cited. Sources checked 2026-10-19. HTML: https://unstale.sh/npm/viem/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## viem 2

### Breaking changes

- Renamed the experimental native multisig APIs to configurable accounts, following TIP-1107. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)
- Now builds the manager from a Store instead of a custom get/set/remove source. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)

### Security

- Preserves relay-filled validBefore and validAfter bounds so sponsored Tempo transactions retain a valid fee-payer signature. (2.57.7) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.7)

### New APIs and options

- Added the ousd token address to Addresses in viem/tempo. (2.57.6) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.6)
- Tempo actions now provide typed TempoExecutionError errors, with per-module subclasses carrying decoded arguments, fetched onchain details, and resolution hints. (2.57.6) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.6)
- Added an action for saving authorizations signed elsewhere. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)
- Added the QMS Testnet chain. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)
- Added a Tempo plugin that saves key authorizations signed with Actions.accessKey.signAuthorization and attaches them to the access key's next transaction, including configurable account authorizations at quorum. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)

### Behavior and default changes

- Updated the RPC and block explorer URLs from arc.network to arc.io. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)
- Updated the Tempo mainnet and testnet Earn factory addresses to the latest releases. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)

### Fixes and other changes

- The transport timeout now applies while reading the response body and when the request is given an abort signal. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)
- No longer drops the first parameter when a space follows an opening parenthesis; the same fix applies to toFunctionSelector, toEventSelector, and toSignature. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)
- Calling unsubscribe on webSocket and ipc transports after reconnect now uses the current subscription id, preventing subscription leaks. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)
- Concurrent waits no longer resolve using the first call's options or leave a later wait for the same id hanging. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)
- Now detects replacement transactions and avoids reporting a repriced transaction as replaced when RPC address casing differs. (2.57.5) — [release notes](https://github.com/wevm/viem/releases/tag/viem%402.57.5)