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Migrate from Wrangler 1

This document describes the steps to migrate a project from Wrangler 1 to Wrangler 2.

Wrangler 2 ships with new features and improvements that may require some changes to your configuration.

The CLI itself will guide you through the upgrade process.

Update Wrangler version

The first step is to update to the latest version of Wrangler in your Worker project. If you had previously installed Wrangler 1 globally, you can uninstall it with:

$ npm uninstall -g @cloudflare/wrangler

Now, install the latest version of Wrangler into your project, adding it to your devDependencies:

$ npm install -D [email protected]

To check that you have installed the correct Wrangler version, run:

npx wrangler --version

Build your Worker

Run the wrangler dev command. This will show any warnings or errors that should be addressed. Note that in most cases, the messages will include actionable instructions on how to resolve the issue.

  • Errors need to be fixed before Wrangler can build your Worker.
  • In most cases, you will only see warnings. These do not stop Wrangler from building your Worker, but consider updating the configuration to remove them.
    $ npx wrangler dev

Here is an example of some warnings and errors:

⛅️ wrangler 2.0.0
▲ [WARNING] Processing wrangler.toml configuration:
- 😶 Ignored: "type":
Most common features now work out of the box with wrangler, including modules, jsx,
typescript, etc. If you need anything more, use a custom build.
- Deprecation: "zone_id":
This is unnecessary since we can deduce this from routes directly.
- Deprecation: "build.upload.format":
The format is inferred automatically from the code.
✘ [ERROR] Processing wrangler.toml configuration:
- Expected "route" to be either a string, or an object with shape { pattern, zone_id | zone_name }, but got "".

Common deprecations

Here are common fields that are no longer required.

  • type is no longer required. Wrangler will infer the correct project type automatically.
  • zone_id is no longer required. It can be deduced from the routes directly.
  • build.upload.format is no longer used. The format is now inferred automatically from the code.
  • build.upload.main and build.upload.dir are no longer required. Use the top level main field, which now serves as the entry-point for the Worker.
  • site.entry-point is no longer required. The entry point should be specified through the main field.
  • webpack_config and webpack properties are no longer supported. Refer to Ejecting Webpack .

Here are the Wrangler 1 commands that are no longer supported:

  • wrangler preview - Use the wrangler dev command, for running your worker in your local environment.
  • wrangler generate - If you want to use a starter template, clone its GitHub repository and manually initialize it.
  • wrangler route - Routes are defined in the wrangler.toml configuration file.
  • wrangler report - If you find a bug please report it at Wrangler issues.
  • wrangler build - If you wish to access the output from bundling your Worker use wrangler publish --outdir=path/to/output.

Refer to the deprecations guide for more details on what is no longer supported.