# Environment variables

> Settings and secrets for your app: how to add them, when they apply, which ones are set for you, who sees their values, and the limits.

Environment variables hold what should not be in your code: database addresses, API keys, settings that differ between apps. Your app reads them from `process.env`. They are stored encrypted.

## Add a variable

Open **Variables**, enter a **Key** and a **Value** and choose **Add**.

To add many at once, choose **Bulk edit** and write one `KEY=value` per line. You can paste the content of a `.env` file. Lines you remove are deleted when you save.

## When a change applies

A saved variable reaches the app with the next deployment. After a change, the app shows a notice with **Redeploy now**: it puts the current version online again with the new values.

## Where they are available

| Where | Available |
| --- | --- |
| The running app | Yes |
| [Deploy commands](https://arrangic.com/docs/deploy-commands.md) | Yes |
| Install and build | Only the ones with **Build** turned on |

## During the build

A variable is not set while the app is installed and built, unless you turn on **Build** next to it. Turn it on for what the install or the build really needs:

- a token for a private package, read by your `.npmrc`
- a value your build puts into the built files

Leave it off for everything else, so your build is given no secret it does not need.

A variable with **Build** on is set for the install and the build commands only while they run. It is not stored in the built image.

After you turn **Build** on or off, or change a variable that has it on, the next deployment builds the app again.

> **What the build prints**
>
> Your build can print a variable it was given. Then the value is in your build log, where everyone in your team can read it.

## Names

A name is made of capital letters, digits and underscores, and does not start with a digit: `DATABASE_URL`, `STRIPE_KEY`, `MAX_ITEMS`.

## Set for you

These are set for every app. You cannot change or remove them:

| Variable | Value |
| --- | --- |
| `PORT` | The port from your [build settings](https://arrangic.com/docs/build-settings.md#port), 3000 unless you change it |
| `NODE_ENV` | `production` |
| `APP_URL` | The address of your app, with `https://` |

Names that start with `PLATFORM_` are kept for the platform as well.

## Who sees the values

| Role | Can set variables | Can see values |
| --- | --- | --- |
| Owner | Yes | Yes |
| Admin | Yes | Yes |
| Member | Yes | No |

See [Teams](https://arrangic.com/docs/teams.md) for the roles.

## Limits

| | Limit |
| --- | --- |
| Variables for one app | 200 |
| One value | 32 KB |
| All names and values together | 256 KB |

## A .env file

A `.env` file that is not committed does not exist on the platform, and it should not be committed. Add its content under **Variables** instead. A package like `dotenv` does no harm: it finds no file and the variables are already set.

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This page on the site: https://arrangic.com/docs/environment-variables  
All pages of the documentation: https://arrangic.com/llms.txt