> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mirurobotics.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Opaque

An opaque schema is a metadata-only schema that regards all config instances as valid.

Opaque schemas are useful for config formats which do not have a supported schema language. At the time of writing, this includes:

* XML configuration files
* Plain text configuration files (`.conf`, `.txt`, etc.)

## Example

Below are examples of opaque schemas:

<CodeGroup>
  ```yaml XML theme={null}
  language: opaque
  config_type: motion-control
  instance_filepath: /srv/miru/configs/motion-control.xml
  instance_format: xml
  ```

  ```yaml Plain Text theme={null}
  language: opaque
  config_type: motion-control
  instance_filepath: /srv/miru/configs/motion-control.conf
  instance_format: text
  ```
</CodeGroup>

Consult the [schema annotations](/cfg-mgmt/primitives/schemas/overview#schema-annotations) documentation to learn more about what the individual fields mean and how to use them.

## File formats

Opaque schemas themselves are written as JSON or YAML. Unlike the other languages, CUE is not accepted here:

* **JSON** (`.json`)
* **YAML** (`.yaml`, `.yml`)

Opaque schemas accept the widest set of config instance formats of any Miru schema language:

* **JSON**
* **YAML**
* **XML**
* **Text**

<Note>
  YAML support requires Miru Agent **v0.7.0** or newer
</Note>