---
title: env_get
description: Read a value from a task environment while evaluating Starlark.
---

# `env_get`

`env_get` reads an environment variable while the Starlark file is evaluated. It returns a string when the variable exists and `None` when it does not. Reading a value does not modify the base environment or any task.

## Arguments

| Argument | Required | Description |
| --- | --- | --- |
| `key` | Yes | Environment variable name to read. |
| `deps` | No | Dependencies applied to an environment clone before reading. Defaults to `[]`. |

## Examples

### Read a base value

```python
load("@os@1", "env_get")

system_path = env_get("PATH")
```

### Read a composed environment

```python
load("@os@1", "env_get", "env_set")

go_flags = env_get(
    "GOFLAGS",
    deps=[env_set("GOFLAGS", "-trimpath")],
)

print(go_flags)
```

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