# Configuration

When you deploy to the Mastra platform, the CLI generates a `.mastra-project.json` config file and reads environment variables from your local `.env` files.

This page explains both mechanisms and how they differ between Studio and Server deployments.

## Project config

The `.mastra-project.json` file is auto-generated on your first Studio or Server deploy. It links your local project to a platform project.

Commit it to your version control so that subsequent deploys (including from CI) target the correct project.

Your file will look something like this:

```json
{
  "projectId": "06daaac4-89b1-40f0-9e3f-0993e039a627",
  "projectName": "my-project",
  "organizationId": "org_01KNA5YSP52SX4M6YVSXC2MAHP"
}
```

| Field          | Description                                                                                          |
| -------------- | ---------------------------------------------------------------------------------------------------- |
| projectId      | UUID for the project. Assigned when the project is created.                                          |
| projectName    | Human-readable project name. Used as a display label in the dashboard and CLI output.                |
| organizationId | The organization that owns the project. All deploys, API keys, and resources are scoped to this org. |

## Environment variables

The CLI reads from `.env` and `.env.local` files in your project directory during deploy. Variables from `.env.local` override those in `.env`.

You can set environment variables like so:

- **Studio**: Environment variables are read from your local `.env` files and bundled into the deploy artifact. To update them, redeploy.
- **Server**: On the first deploy, the CLI automatically seeds environment variables from your local `.env` files. After that, manage them per-project through the dashboard or API.