Bun supports loading configuration options from .npmrc files, allowing you to reuse existing registry/scope configurations.

NOTE

We recommend migrating your `.npmrc` file to Bun's [`bunfig.toml`](/runtime/bunfig) format, as it provides more flexible options and can let you configure Bun-specific options.

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Supported options

Set the default registry

The default registry is used to resolve packages, its default value is npm's official registry (https://registry.npmjs.org/).

To change it, you can set the registry option in .npmrc:

registry=http://localhost:4873/

The equivalent bunfig.toml option is install.registry:

install.registry = "http://localhost:4873/"

Set the registry for a specific scope

@<scope>:registry allows you to set the registry for a specific scope:

@myorg:registry=http://localhost:4873/

The equivalent bunfig.toml option is to add a key in install.scopes:

[install.scopes]
myorg = "http://localhost:4873/"

Configure options for a specific registry

//<registry_url>/:<key>=<value> allows you to set options for a specific registry:

# set an auth token for the registry
# ${...} is a placeholder for environment variables
//http://localhost:4873/:_authToken=${NPM_TOKEN}


# or you could set a username and password
# note that the password is base64 encoded
//http://localhost:4873/:username=myusername

//http://localhost:4873/:_password=${NPM_PASSWORD}

# or use _auth, which is your username and password
# combined into a single string, which is then base 64 encoded
//http://localhost:4873/:_auth=${NPM_AUTH}

The following options are supported:

• _authToken
• username
• _password (base64 encoded password)
• _auth (base64 encoded username:password, e.g. btoa(username + ":" + password))

The equivalent bunfig.toml option is to add a key in install.scopes:

[install.scopes]
myorg = { url = "http://localhost:4873/", username = "myusername", password = "$NPM_PASSWORD" }

link-workspace-packages: Control workspace package installation

Controls how workspace packages are installed when available locally:

link-workspace-packages=true

The equivalent bunfig.toml option is install.linkWorkspacePackages:

[install]
linkWorkspacePackages = true

save-exact: Save exact versions

Always saves exact versions without the ^ prefix:

save-exact=true

The equivalent bunfig.toml option is install.exact:

[install]
exact = true