---
title: "Environment Variables and Modes"
locale: "en"
version: "1.x"
canonicalUrl: "https://farmfe.org/docs/1.x/features/env"
publicationStatus: "prerelease"
---

<a id="environment-variables-and-modes"></a>
# Environment Variables and Modes


` Farm ` distinguishes between ` development ` and ` production ` environments through ` process.env.NODE_ENV `.


In different environments, environment variables are replaced statically, so use static constants to represent environment variables instead of dynamic expressions.


<a id="env-file"></a>
## ` .env ` file


` Farm ` uses ` dotenv ` to load your additional environment variables, such as ` .env ` files. By default ` .env ` file are loaded from [` root `](</docs/config/shared#root>), you can use [` envDir `](</docs/1.x/features/env#envdir>) to customize.


```js
// .env
FARM_APP_SECRET=secret
Farm_APP_PASSWORD=password
APP_VERSION=1.0.0
```


` Farm ` loads the file ` .env ` via dotenv, and loads it into ` process.env ` and finally injects it into define.



> [!DANGER]
> danger
> 
> In order to ensure the security of the client, preventing the environment variables in the current system from being exposed to the client ` Farm ` will only identify some important environment variables that start with ` FARM_ `、` VITE_ ` (In order to better compatible with vite and its ecological environment).



` Farm ` expands environment variables through dotenv-expand. For development only envs use ` .env.development `, for production only envs use ` .env.production `, for custom mode passed by ` --mode <stage> `, load from ` .env.<stage> ` file.


- If you want to customize the directory to load ` .env ` file, you can configure [` envDir `](</docs/1.x/features/env#envdir>).
- If you want to customize the prefix of env variables which are injected to [` define `](</docs/config/compilation-options#define>), you can configure [` envPrefix `](</docs/1.x/features/env#envprefix>).


<a id="envprefix"></a>
## envPrefix


- **default value**: ` FARM_ `、` VITE_ `


Customize the prefix of the ` env ` variable by configuring ` envPrefix `. Env variables start with ` envPrefix ` will be injected into define automatically. For example, in the ` .env ` file:


```js
// .env
FARM_CUSTOM_VERSION=1.0.0
APP_VERSION=0.1.0
```


Then ` FARM_CUSTOM_VERSION ` will be injected, but not ` APP_VERSION `, in your business code:


```tsx
export function MyComp() {
  const farmCustomVersion = FARM_CUSTOM_VERSION;
  return <div>Farm Custom Version: {farmCustomVersion}</div>
}
```


` FARM_CUSTOM_VERSION ` will be replaced by ` '1.0.0' ` automatically.


<a id="envdir"></a>
## envDir


- **default value**: ` <root> `


The directory to load [` env file `](</docs/1.x/features/env#env-file>). By default Farm load ` env file ` from root.


```ts
export defineConfig({
  envDir: './env'
})
```


For above config example, Farm will load ` .env `, ` .env.development `, etc from ` <root>/env ` dir.