## Use API key

To use the API key, you either:
- **Set the API key as the `E2B_API_KEY` environment variable**
- Or pass it directly to the `CodeInterpreter` constructor like this:
<CodeGroup isRunnable={false}>
```js {{ language: 'js' }}
import { CodeInterpreter } from '@e2b/code-interpreter'

const sandbox = await CodeInterpreter.create({ apiKey: 'YOUR_API_KEY' })
await sandbox.notebook.execCell('x = 1')

const execution = await sandbox.notebook.execCell('x+=1; x')
console.log(execution.text)  // outputs 2

await sandbox.close()
```
```python {{ language: 'python' }}
from e2b_code_interpreter import CodeInterpreter

with CodeInterpreter(api_key="YOUR_API_KEY") as code_interpreter:
  sandbox.notebook.exec_cell("x = 1")
  execution = sandbox.notebook.exec_cell("x+=1; x")
  print(execution.text)  # outputs 2
```
</CodeGroup>
