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

# Development Setup

> Get your local development environment ready for contributing to the Sentry JavaScript SDK.

This guide will help you set up your local development environment for contributing to the Sentry JavaScript SDK monorepo.

## Prerequisites

### Volta

We use [Volta](https://volta.sh/) to ensure consistent versions of Node.js, Yarn, and pnpm across all contributors. Volta automatically manages the correct versions based on the `volta` field in `package.json`.

Install Volta:

```bash theme={null}
curl https://get.volta.sh | bash
```

For more installation options, see the [Volta documentation](https://docs.volta.sh/guide/getting-started).

### Enable pnpm Support

Make sure to enable [pnpm support in Volta](https://docs.volta.sh/advanced/pnpm) if you want to run the E2E tests locally:

```bash theme={null}
export VOLTA_FEATURE_PNPM=1
```

Add this to your shell configuration file (`.bashrc`, `.zshrc`, etc.) to make it permanent.

### Python

<Note>
  Due to package incompatibilities, building native binaries currently requires Python version \< 3.12.
</Note>

## Initial Setup

Once you have the prerequisites installed, clone the repository and install dependencies:

```bash theme={null}
# Clone the repository
git clone https://github.com/getsentry/sentry-javascript.git
cd sentry-javascript

# Install all dependencies
yarn

# Perform an initial build
yarn build
```

The initial build is important because it:

* Transpiles TypeScript code to JavaScript
* Generates type definitions
* Links packages together in the monorepo
* Ensures TypeScript can read all linked type definitions

With that, the repo is fully set up and you are ready to run all commands.

## Monorepo Structure

The Sentry JavaScript SDK is a monorepo containing 40+ packages, managed with [Yarn workspaces](https://classic.yarnpkg.com/en/docs/workspaces/) and [Nx](https://nx.dev/).

```
sentry-javascript/
├── packages/              # SDK packages (@sentry/*)
│   ├── core/             # Base SDK implementation
│   ├── browser/          # Browser SDK
│   ├── node/             # Node.js SDK
│   ├── react/            # React integration
│   └── ...               # 40+ more packages
├── dev-packages/         # Development and testing packages
│   ├── browser-integration-tests/
│   ├── e2e-tests/
│   ├── node-integration-tests/
│   └── test-utils/
├── docs/                 # Documentation and guides
└── scripts/              # Build and automation scripts
```

## Workspace Configuration

All workspaces are defined in the root `package.json:workspaces` field:

```json theme={null}
"workspaces": [
  "packages/angular",
  "packages/browser",
  "packages/core",
  "packages/node",
  "dev-packages/browser-integration-tests",
  "dev-packages/e2e-tests",
  // ... and more
]
```

## Version Management

Volta pins specific versions in `package.json`:

```json theme={null}
"volta": {
  "node": "20.19.2",
  "yarn": "1.22.22",
  "pnpm": "9.15.9"
}
```

<Warning>
  Never change Volta, Yarn, or package manager versions unless explicitly asked or approved by the core team.
</Warning>

## Verifying Your Setup

After completing the initial setup, verify everything is working:

```bash theme={null}
# Check that the build completed successfully
ls packages/core/build

# Run a simple test
cd packages/core
yarn test
```

If you see the `build/` directory with `cjs/`, `esm/`, and `types/` subdirectories, and tests pass, your environment is ready!

## Next Steps

Now that your environment is set up, you can:

* [Build packages](/contributing/building) for development
* [Run tests](/contributing/testing) to verify your changes
* Learn about the [development workflow](/contributing/workflow)
* Explore the [monorepo architecture](/contributing/architecture/overview)