Migrate to Vitest plugin

Last updated Aug 20, 2026 @cloudflare/vitest-plugin replaces @cloudflare/vitest-pool-workers. The package API and Vitest configuration are unchanged.

Run the codemod

To update your project automatically, run the following command from the project root:

npmyarnpnpm

npx @cloudflare/codemods vitest:pool-workers-to-vitest-plugin

yarn @cloudflare/codemods vitest:pool-workers-to-vitest-plugin

pnpm @cloudflare/codemods vitest:pool-workers-to-vitest-plugin

Use --dry-run to preview the changes. Use --files <glob> to limit the files the codemod updates.

The codemod updates your dependency, imports, and test TypeScript configuration.

Update manually

If you cannot run the codemod, update the package name in your package.json, imports, and test tsconfig.json:

- "@cloudflare/vitest-pool-workers": "^0.16.0"
+ "@cloudflare/vitest-plugin": "^1.0.0"

- import { cloudflareTest } from "@cloudflare/vitest-pool-workers";
+ import { cloudflareTest } from "@cloudflare/vitest-plugin";

- "types": ["@cloudflare/vitest-pool-workers/types"]
+ "types": ["@cloudflare/vitest-plugin/types"]

The same rename applies to subpath imports, including @cloudflare/vitest-plugin/config.

Update request mocking

To mock outbound requests, use @msw/cloudflare ↗︎. For setup instructions, refer to Mock outbound requests.

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description: Mock outbound HTTP and WebSocket requests when testing Workers with the Vitest plugin. title: Mock outbound requests image: https://developers.cloudflare.com/workers/testing/vitest-integration/mock-outbound-requests/og.png?v=953487ab876c21e0

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