> ## Documentation Index
> Fetch the complete documentation index at: https://docs.replit.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Dependency Management

> Learn how to install and manage packages and dependencies for your Replit App across different languages.

Replit provides several ways to install and manage packages for your Replit App. You can install packages using the [Shell](/core-concepts/project-editor/editor-and-tools/shell), ask [Agent](/core-concepts/agent/) to handle it for you, or let Replit automatically detect and install missing dependencies when you run your Replit App.

## Install packages using the Shell

Open the **Shell** tool in the Project Editor and run the appropriate command for your language's package manager:

<CodeGroup>
  ```bash Node.js (npm) theme={null}
  npm install <package-name>
  ```

  ```bash Node.js (pnpm) theme={null}
  pnpm add <package-name>
  ```

  ```bash Python (poetry) theme={null}
  poetry add <package-name>
  ```

  ```bash Python (pip) theme={null}
  pip install <package-name>
  ```

  ```bash Ruby theme={null}
  bundle add <gem-name>
  ```
</CodeGroup>

You can also use Replit's [Universal Package Manager (UPM)](https://github.com/replit/upm/) to install packages across supported languages:

```bash theme={null}
upm add <package-name>
```

To install a specific version:

```bash theme={null}
upm add 'flask==2.3.3'
```

For all supported languages and package managers, see [UPM: Supported Languages](https://github.com/replit/upm/#supported-languages).

## Install packages using Agent

You can ask [Agent](/core-concepts/agent/) to install packages for you directly in chat. For example:

* "Install the axios package"
* "Add Flask and SQLAlchemy to my project"
* "Set up TailwindCSS"

Agent installs the package using the appropriate package manager for your project and updates the relevant configuration files.

## Automatic import detection

Replit automatically analyzes your code for missing dependencies each time you select **Run**. If your code imports a package that is not yet installed, Replit detects it and installs the latest version automatically.

For example, if you add `import flask` to `main.py`, the next time you select **Run**, the **Console** displays a message indicating that **Flask** is being installed.

<Note>
  You can configure automatic import detection in the [.replit](/core-concepts/project-editor/app-setup/configuration#replit-file) file using the `packager.features.guessImports` setting.
</Note>

### Override automatic detection

If the wrong package was detected, or you need a specific version, run the correct install command in the Shell. For example:

```bash theme={null}
upm add 'flask==2.3.3'
```

You can also exclude specific packages or paths from automatic detection in your [.replit](/core-concepts/project-editor/app-setup/configuration#replit-file) file:

## Python package managers

When you create a Python Replit App, your package manager is **poetry** by default. This means `pip install` does not manage your dependencies. Instead, use `poetry add <package>` or `upm add <package>` in the Shell.

### Switch from poetry to pip

If you prefer using `pip`, follow these steps:

<Steps>
  <Step>
    Open the Shell and run:

    Remove the lock file so that the packaging infrastructure switches to pip:

    ```bash theme={null}
    rm poetry.lock
    ```
  </Step>

  <Step title="Move your dependencies">
    Transfer your dependencies from the `[tool.poetry.dependencies]` section in `pyproject.toml` to `requirements.txt`. For example, `flask = "^3.0.2"` becomes `flask>=3.0.2,<4`.
  </Step>

  <Step title="Clean up pyproject.toml">
    Delete the `[tool.poetry...]` sections from `pyproject.toml`.
  </Step>
</Steps>

After these changes, the packaging infrastructure uses `pip` for all future operations, and automatic import detection continues to work as expected.

## System dependencies with Nix

Replit supports all programming languages through integration with [Nix](https://nixos.org/). If you need system-level dependencies beyond standard language packages, you can add them to your [replit.nix](/core-concepts/project-editor/app-setup/configuration#replit-nix-file) file.

### Nix packages

Add system-level dependencies by editing `replit.nix` directly. You can search for available packages at [search.nixos.org](https://search.nixos.org/packages).

### Modules

Modules combine support for programming languages, formatters, and packagers. They provide the foundation for your Replit App. If you create a Replit App from a template or GitHub repository, Replit automatically installs the required modules.

You can customize modules and other Nix settings using the [.replit](/core-concepts/project-editor/app-setup/configuration#replit-file) file.

## Packager configuration

You can fine-tune package management behavior in your [.replit](/core-concepts/project-editor/app-setup/configuration#replit-file) file:

| Setting                               | Description                                              | Default                |
| ------------------------------------- | -------------------------------------------------------- | ---------------------- |
| `packager.language`                   | Language used for package operations                     | Detected automatically |
| `packager.features.guessImports`      | Automatically detect and install missing packages on Run | `true`                 |
| `packager.features.packageSearch`     | Enable package search support                            | `true`                 |
| `packager.features.enabledForHosting` | Require package installation when hosting                | `false`                |
| `packager.afterInstall`               | Command to run after a package is installed              | —                      |
| `packager.ignoredPaths`               | Paths to ignore during import detection                  | `[]`                   |
| `packager.ignoredPackages`            | Packages to exclude from automatic detection             | `[]`                   |