Change8

Migrating to Cloudflare Workers wrangler@4.111.0

Version wrangler@4.111.0 introduces 1 breaking change. This guide details how to update your code.

Released: 7/15/2026

1
Breaking Changes
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Migration Steps
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Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

`createTestHarness``wrangler dev``wrangler pages deploy``wrangler pages project create`Vite plugin`wrangler.config.ts``worker-configuration.d.ts``dev.types.includeRuntime`

Breaking Changes

Issue #1

Service environments have been removed. The `legacy_env` configuration field is no longer supported and will raise an error if present in your configuration file. If you were previously using `legacy_env = false`, each environment will now be deployed as a standalone Worker instead of an environment of a single Worker. Refer to https://developers.cloudflare.com/workers/wrangler/environments/ for more information on the new deployment behavior.

Migration Steps

  1. 1
    Remove the `legacy_env` field from your Wrangler configuration file if it is present.

Release Summary

This release removes support for service environments and the `legacy_env` configuration field, simplifying deployment. It also introduces Durable Object eviction support in `createTestHarness` and improves type generation for the experimental new config path.

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View the full release notes and all changes for Cloudflare Workers wrangler@4.111.0.

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