Third-Party Packages

Dagger Functions are just regular code, written in your usual programming language. One of the key advantages of this approach is that it opens up access to your language's existing ecosystem of packages or modules. You can easily import these packages/modules in your Dagger module via your language's package manager.

Go

To add a Go module, add it to your go.mod file using go get. For example:

go get github.com/spf13/cobra

Dagger lets you import private Go modules in your Dagger module. To do this, add the URL to the private repository(ies) hosting the module(s) in a config.goprivate key in the module's dagger.json file, as shown below:

{
  "sdk": {
    "source": "go",
    "config": {
      "goprivate": "github.com/user/repository",
    },
  },
}

Multiple URLs can be specified as comma-separated values. The repository name is optional; if left unspecified, all modules under the specified prefix will be included. For example, setting the goprivate URL to github.com/username will include all private modules with the github.com/username prefix.

Note that this feature requires a .gitconfig file entry to use SSH instead of HTTPS for the host. Use the command git config --global url."git@github.com:".insteadOf "https://github.com/" to create the necessary .gitconfig entry.

Python

To add a Python package, add it to your pyproject.toml file using your chosen package manager. For example:

uv

uv add requests

poetry

poetry add requests

uv pip

Add the dependency manually to pyproject.toml:

[project]
dependencies = [
    "requirements>=2.32.3",
]

Then install into your virtual environment:

uv pip install -e ./sdk -e .

note

There's no need to activate the virtual environment before uv pip install, but it does need to exist.

pip

Add the dependency manually to pyproject.toml:

[project]
dependencies = [
    "requirements>=2.32.3",
]

Then install into your virtual environment:

python -m pip install -e ./sdk -e .

tip

If you haven't setup your local environment yet, see IDE Integration.

note

Third-party dependencies are managed in the same way as any normal Python project. The only limitation is in "pinning" the dependencies. Currently, Dagger can install directly from a uv.lock file, or a pip-tools compatible requirements.lock file (notice .lock extension, not .txt). See Language-native packaging for more information.

TypeScript

To add a TypeScript package, add it to the package.json file using your favorite package manager. For example:

npm install pm2

Pinning a specific dependency version or adding local dependencies are supported, in the same way as any Node.js project.

PHP

To add a PHP package, add it to the composer.json file, the same way as any PHP project. For example:

composer require phpunit/phpunit

note

Dagger modules installed as packages via Composer are not registered with Dagger.

You can access its code, like any other PHP package, but this is not the indended use-case of a Dagger module. This may lead to unexpected behaviour.

Use Composer for standard third-party packages.

Use Dagger to install Dagger modules

Java

To add a Java package, add it to your pom.xml file using Maven. For example:

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-simple</artifactId>
    <scope>runtime</scope>
    <version>2.0.16</version>
</dependency>