Catalogs

"Catalogs" are a workspace feature for defining dependency version ranges as reusable constants. Constants defined in catalogs can later be referenced in package.json files.

The Catalog Protocol (catalog:)

Once a catalog is defined in pnpm-workspace.yaml,

pnpm-workspace.yaml

packages:
  - packages/*

# Define a catalog of version ranges.
catalog:
  react: ^18.3.1
  redux: ^5.0.1

The catalog: protocol can be used instead of the version range itself.

packages/example-app/package.json

{
  "name": "@example/app",
  "dependencies": {
    "react": "catalog:",
    "redux": "catalog:"
  }
}

This is equivalent to writing a version range (e.g. ^18.3.1) directly.

packages/example-app/package.json

{
  "name": "@example/app",
  "dependencies": {
    "react": "^18.3.1",
    "redux": "^5.0.1"
  }
}

You may use the catalog: protocol in the next fields of your package.json:

• dependencies
• devDependencies
• peerDependencies
• optionalDependencies
• pnpm.overrides

The catalog: protocol allows an optional name after the colon (ex: catalog:name) to specify which catalog should be used. When a name is omitted, the default catalog is used.

Depending on the scenario, the catalog: protocol offers a few advantages compared to writing version ranges directly that are detailed next.

Advantages

In a workspace (i.e. monorepo or multi-package repo) it's common for the same dependency to be used by many packages. Catalogs reduce duplication when authoring package.json files and provide a few benefits in doing so:

• Maintain unique versions — It's usually desirable to have only one version of a dependency in a workspace. Catalogs make this easier to maintain. Duplicated dependencies can conflict at runtime and cause bugs. Duplicates also increase size when using a bundler.
• Easier upgrades — When upgrading a dependency, only the catalog entry in pnpm-workspace.yaml needs to be edited rather than all package.json files using that dependency. This saves time — only one line needs to be changed instead of many.
• Fewer merge conflicts — Since package.json files do not need to be edited when upgrading a dependency, git merge conflicts no longer happen in these files.

Defining Catalogs

Catalogs are defined in the pnpm-workspace.yaml file. There are two ways to define catalogs.

1. Using the (singular) catalog field to create a catalog named default.
2. Using the (plural) catalogs field to create arbitrarily named catalogs.

tip

If you have an existing workspace that you want to migrate to using catalogs, you can use the following codemod:

pnpx codemod pnpm/catalog

Default Catalog

The top-level catalog field allows users to define a catalog named default.

pnpm-workspace.yaml

catalog:
  react: ^18.2.0
  react-dom: ^18.2.0

These version ranges can be referenced through catalog:default. For the default catalog only, a special catalog: shorthand can also be used. Think of catalog: as a shorthand that expands to catalog:default.

Named Catalogs

Multiple catalogs with arbitrarily chosen names can be configured under the catalogs key.

pnpm-workspace.yaml

catalogs:
  # Can be referenced through "catalog:react17"
  react17:
    react: ^17.0.2
    react-dom: ^17.0.2

  # Can be referenced through "catalog:react18"
  react18:
    react: ^18.2.0
    react-dom: ^18.2.0

A default catalog can be defined alongside multiple named catalogs. This might be useful in a large multi-package repo that's migrating to a newer version of a dependency piecemeal.

pnpm-workspace.yaml

catalog:
  react: ^16.14.0
  react-dom: ^16.14.0

catalogs:
  # Can be referenced through "catalog:react17"
  react17:
    react: ^17.0.2
    react-dom: ^17.0.2

  # Can be referenced through "catalog:react18"
  react18:
    react: ^18.2.0
    react-dom: ^18.2.0

Pubblicazione

The catalog: protocol is removed when running pnpm publish or pnpm pack. This is similar to the workspace: protocol, which is also replaced on publish.

Ad esempio,

packages/example-components/package.json

{
  "name": "@example/components",
  "dependencies": {
    "react": "catalog:react18",
  }
}

Will become the following on publish.

packages/example-components/package.json

{
  "name": "@example/components",
  "dependencies": {
    "react": "^18.3.1",
  }
}

The catalog: protocol replacement process allows the @example/components package to be used by other workspaces or package managers.

Caveats

The pnpm update command does not yet support catalogs.

To update dependencies defined in pnpm-workspace.yaml, newer version ranges will need to be chosen manually until a future version of pnpm handles this.