Deprecations

Review the difference between Wrangler versions, specifically deprecations and breaking changes.

Wrangler v3

Deprecated commands

The following commands are deprecated in Wrangler as of Wrangler v3. These commands will be fully removed in a future version of Wrangler.

`generate`

The wrangler generate command is deprecated, but still active in v3. wrangler generate will be fully removed in v4.

Use npm create cloudflare@latest for new Workers and Pages projects.

`publish`

The wrangler publish command is deprecated, but still active in v3. wrangler publish will be fully removed in v4.

Use npx wrangler deploy to deploy Workers.

`pages publish`

The wrangler pages publish command is deprecated, but still active in v3. wrangler pages publish will be fully removed in v4.

Use wrangler pages deploy to deploy Pages.

Deprecated options

`--experimental-local`

wrangler dev in v3 is local by default so this option is no longer necessary.

`--local`

wrangler dev in v3 is local by default so this option is no longer necessary.

`--persist`

wrangler dev automatically persists data by default so this option is no longer necessary.

`-- <command>`, `--proxy`, and `--script-path` in `wrangler pages dev`

These options prevent wrangler pages dev from being able to accurately emulate production’s behavior for serving static assets and have therefore been deprecated. Instead of relying on Wrangler to proxy through to some other upstream dev server, you can emulate a more accurate behavior by building your static assets to a directory and pointing Wrangler to that directory with wrangler pages dev <directory>.

Wrangler v2

Wrangler v2 introduces new fields for configuration and new features for developing and deploying a Worker, while deprecating some redundant fields.

wrangler.toml is no longer mandatory.
dev and publish accept CLI arguments.
tail can be run on arbitrary Worker names.
init creates a project boilerplate.
JSON bindings for vars.
Local mode for wrangler dev.
Module system (for both modules and service worker format Workers).
DevTools.
TypeScript support.
Sharing development environment on the Internet.
Wider platform compatibility.
Developer hotkeys.
Better configuration validation.

The following video describes some of the major changes in Wrangler v2, and shows you how Wrangler v2 can help speed up your workflow.

Common deprecations

Refer to the following list for 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 Migrate webpack projects from Wrangler version 1. Here are the Wrangler v1 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, 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.

New fields

These are new fields that can be added to your wrangler.toml.

main: string, optional

The main field is used to specify an entry point to the Worker. It may be in the established service worker format, or the newer, preferred modules format. An entry point is now explicitly required, and can be configured either via the main field, or passed directly as a command line, for example, wrangler dev index.js. This field replaces the legacy build.upload.main field (which only applied to modules format Workers).
rules: array, optional

The rules field is an array of mappings between module types and file patterns. It instructs Wrangler to interpret specific files differently than JavaScript. For example, this is useful for reading text-like content as text files, or compiled WASM as ready to instantiate and execute. These rules can apply to Workers of both the established service worker format, and the newer modules format. This field replaces the legacy build.upload.rules field (which only applied to modules format Workers).

Non-mandatory fields

A few configuration fields which were previously required, are now optional in particular situations. They can either be inferred, or added as an optimization. No fields are required anymore when starting with Wrangler v2, and you can gradually add configuration as the need arises.

name: string

The name configuration field is now not required for wrangler dev, or any of the wrangler kv:* commands. Further, it can also be passed as a command line argument as --name <name>. It is still required for wrangler publish.
account_id: string

The account_id field is not required for any of the commands. Any relevant commands will check if you are logged in, and if not, will prompt you to log in. Once logged in, it will use your account ID and will not prompt you again until your login session expires. If you have multiple account IDs, you will be presented with a list of accounts to choose from.

You can still configure account_id in your wrangler.toml file, or as an environment variable CLOUDFLARE_ACCOUNT_ID. This makes startup faster and bypasses the list of choices if you have multiple IDs. The CLOUDFLARE_API_TOKEN environment variable is also useful for situations where it is not possible to login interactively. To learn more, visit Running in CI/CD.
workers_dev boolean, default: true when no routes are present

The workers_dev field is used to indicate that the Worker should be published to a *.workers.dev subdomain. For example, for a Worker named my-worker and a previously configured *.workers.dev subdomain username, the Worker will get published to my-worker.username.workers.dev.com. This field is not mandatory, and defaults to true when route or routes are not configured. When routes are present, it defaults to false. If you want to neither publish it to a *.workers.dev subdomain nor any routes, set workers_dev to false. This useful when you are publishing a Worker as a standalone service that can only be accessed from another Worker with (services).

Deprecated fields (non-breaking)

A few configuration fields are deprecated, but their presence is not a breaking change yet. It is recommended to read the warning messages and follow the instructions to migrate to the new configuration. They will be removed and stop working in a future version.

zone_id: string, deprecated

The zone_id field is deprecated and will be removed in a future release. It is now inferred from route/routes, and optionally from dev.host when using wrangler dev. This also makes it simpler to deploy a single Worker to multiple domains.
build.upload: object, deprecated

The build.upload field is deprecated and will be removed in a future release. Its usage results in a warning with suggestions on rewriting the configuration file to remove the warnings.
- build.upload.main/build.upload.dir are replaced by the main fields and are applicable to both service worker format and modules format Workers.
- build.upload.rules is replaced by the rules field and is applicable to both service worker format and modules format Workers.
- build.upload.format is no longer specified and is automatically inferred by wrangler.

Deprecated fields (breaking)

A few configuration fields are deprecated and will not work as expected anymore. It is recommended to read the error messages and follow the instructions to migrate to the new configuration.

site.entry-point: string, deprecated

The site.entry-point configuration was used to specify an entry point for Workers with a [site] configuration. This has been replaced by the top-level main field.
type: rust | javascript | webpack, deprecated

The type configuration was used to specify the type of Worker. It has since been made redundant and is now inferred from usage. If you were using type = "webpack" (and the optional webpack_config field), you should read the webpack migration guide to modify your project and use a custom build instead.

Deprecated commands

The following commands are deprecated in Wrangler as of Wrangler v2.

`build`

The wrangler build command is no longer available for building the Worker.

The equivalent functionality can be achieved by wrangler publish --dry-run --outdir=path/to/build.

`config`

The wrangler config command is no longer available for authenticating via an API token.

Use wrangler login / wrangler logout to manage OAuth authentication, or provide an API token via the CLOUDFLARE_API_TOKEN environment variable.

`preview`

The wrangler preview command is no longer available for creating a temporary preview instance of the Worker.

Try using wrangler dev to try out a worker during development.

subdomain

The wrangler subdomain command is no longer available for creating a workers.dev subdomain.

Create the workers.dev subdomain in Workers & Pages > select your Worker > Your subdomain > Change.

route

The wrangler route command is no longer available to configure a route for a Worker.

Routes are specified in the wrangler.toml configuration file.

Other deprecated behavior

Cloudflare dashboard-defined routes will not be added alongside Wrangler-defined routes. Wrangler-defined routes are the route or routes key in your wrangler.toml. If both are defined, only routes defined in wrangler.toml will be valid. To manage routes via the Cloudflare dashboard only, remove any route and routes keys from and add workers_dev = false to your wrangler.toml file.
Wrangler will no longer use index.js in the directory where wrangler dev is called as the entry point to a Worker. Use the main configuration field, or explicitly pass it as a command line argument, for example: wrangler dev index.js.
Wrangler will no longer assume that bare specifiers are file names if they are not represented as a path. For example, in a folder like so:
```
project
├── index.js
└── some-dependency.js
```
where the content of index.js is:
```
import SomeDependency from "some-dependency.js";

addEventListener("fetch", (event) => {
  // ...
});
```
Wrangler v1 would resolve import SomeDependency from "some-dependency.js"; to the file some-dependency.js. This will also work in Wrangler v2, but will also log a deprecation warning. In the future, this will break with an error. Instead, you should rewrite the import to specify that it is a relative path, like so:
```
import SomeDependency from "some-dependency.js";
import SomeDependency from "./some-dependency.js";
```

Wrangler v1 and v2 comparison tables

Commands

Command	v1	v2	Notes
`publish`	✅	✅
`dev`	✅	✅
`preview`	✅	❌	Removed, use `dev` instead.
`init`	✅	✅
`generate`	✅	❌	Removed, use `git clone` instead.
`build`	✅	❌	Removed, invoke your own build script instead.
`secret`	✅	✅
`route`	✅	❌	Removed, use `publish` instead.
`tail`	✅	✅
`kv`	✅	✅
`r2`	🚧	✅	Introduced in Wrangler v1.19.8.
`pages`	❌	✅
`config`	✅	❓
`login`	✅	✅
`logout`	✅	✅
`whoami`	✅	✅
`subdomain`	✅	❓
`report`	✅	❌	Removed, error reports are made interactively.

Configuration

Property	v1	v2	Notes
`type = "webpack"`	✅	❌	Removed, refer to this guide to migrate.
`type = "rust"`	✅	❌	Removed, use `workers-rs` ↗ instead.
`type = "javascript"`	✅	🚧	No longer required, can be omitted.

Features

Feature	v1	v2	Notes
TypeScript	❌	✅	You can give wrangler a TypeScript file, and it will automatically transpile it to JavaScript using `esbuild` ↗ under-the-hood.
Local mode	❌	✅	`wrangler dev --local` will run your Worker on your local machine instead of on our network. This is powered by Miniflare ↗.

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Deprecations

Wrangler v3

Deprecated commands

generate

publish

pages publish

Deprecated options

--experimental-local

--local

--persist

-- <command>, --proxy, and --script-path in wrangler pages dev

Wrangler v2

Common deprecations

New fields

Non-mandatory fields

Deprecated fields (non-breaking)

Deprecated fields (breaking)

Deprecated commands

build

config

preview

subdomain

route

Other deprecated behavior

Wrangler v1 and v2 comparison tables

Commands

Configuration

Features

`generate`

`publish`

`pages publish`

`--experimental-local`

`--local`

`--persist`

`-- <command>`, `--proxy`, and `--script-path` in `wrangler pages dev`

`build`

`config`

`preview`