> ## Documentation Index
> Fetch the complete documentation index at: https://bazel-pr-29804.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# config_common

Functions for Starlark to interact with Blaze's configurability APIs.

## Members

* [FeatureFlagInfo](#FeatureFlagInfo)
* [toolchain\_type](#toolchain_type)

## FeatureFlagInfo

```
Provider config_common.FeatureFlagInfo
```

The key used to retrieve the provider containing config\_feature\_flag's value.

## toolchain\_type

```
toolchain_type config_common.toolchain_type(name, *, mandatory=True)
```

Declare a rule's dependency on a toolchain type.

### Parameters

| Parameter   | Description                                                                                                                                           |
| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------- |
| `name`      | [string](/versions/8.6.0/rules/lib/core/string); or [Label](/versions/8.6.0/rules/lib/builtins/Label); required  The toolchain type that is required. |
| `mandatory` | [bool](/versions/8.6.0/rules/lib/core/bool); default is `True`  Whether the toolchain type is mandatory or optional.                                  |