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This page covers how to set and use environment variables in a sandbox, and default environment variables inside the sandbox.

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Default environment variables

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Knowing if you are inside a sandbox

Sometimes it’s useful to know if the code is running inside a sandbox. Upon creating a sandbox, useful sandbox metadata is set as environment variables for commands:
  • E2B_SANDBOX is set to true for processes to know if they are inside our VM.
  • E2B_SANDBOX_ID to know the ID of the sandbox.
  • E2B_TEAM_ID to know the team ID that created the sandbox.
  • E2B_TEMPLATE_ID to know what template was used for the current sandbox.
You can try it out by running the following code in the sandbox: 
const sandbox = await Sandbox.create()
const result = await sandbox.commands.run('echo $E2B_SANDBOX_ID')
These default environment variables are only accessible via the SDK, when using the CLI you can find them in the form of dot files in the /run/e2b/ dir:
user@e2b:~$ ls -a /run/e2b/
.E2B_SANDBOX  .E2B_SANDBOX_ID  .E2B_TEAM_ID  .E2B_TEMPLATE_ID

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Setting environment variables

There are 3 ways to set environment variables in a sandbox:
  1. Global environment variables when creating the sandbox.
  2. When running code in the sandbox.
  3. When running commands in the sandbox.

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1. Global environment variables

You can set global environment variables when creating a sandbox. 
import { Sandbox } from '@e2b/code-interpreter'

const sandbox = await Sandbox.create({
  envs: {
    MY_VAR: 'my_value',
  },
})

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2. Setting environment variables when running code

You can set environment variables for specific code execution call in the sandbox.
  • These environment variables are scoped to the command but are not private in the OS.
  • If you had a global environment variable with the same name, it will be overridden only for the command.
const sandbox = await Sandbox.create()
const result = await sandbox.runCode('import os; print(os.environ.get("MY_VAR"))', {
  envs: {
    MY_VAR: 'my_value',
  },
})

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3. Setting environment variables when running commands

You can set environment variables for specific command execution in the sandbox.
  • These environment variables are scoped to the command but are not private in the OS.
  • If you had a global environment variable with the same name, it will be overridden only for the command.
const sandbox = await Sandbox.create()
sandbox.commands.run('echo $MY_VAR', {
  envs: { 
    MY_VAR: '123', 
  }, 
})
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