> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/ai-sre/ai-sre-for-administrators/set-up-runbook-management/workflows/overview.md).

# Configure Runbook Workflows

This guide explains how to use incident and alert fields in your runbook actions to create dynamic, context-aware automation.

### Overview <a href="#overview" id="overview"></a>

Runbook actions can reference incident and alert data using two expression systems:

* **Mustache template syntax**: `{{incident.field_name}}` or `{{alert.field_name}}` for simple variable substitution
* **CEL expression syntax**: `${{expression}}` for logic, conditions, and transformations

This allows you to:

* Pass contextual information from incidents to runbook actions
* Create dynamic messages with incident details
* Route actions based on severity, service, or custom fields
* Apply logic and transformations with CEL expressions
* Build reusable runbooks that adapt to different scenarios

All field references are configured through **form-based UI inputs** with a data picker that shows available fields based on your selected incident or alert context.

***

### Choosing between Mustache and CEL <a href="#choosing-between-mustache-and-cel" id="choosing-between-mustache-and-cel"></a>

| Feature      | Mustache (`{{variable}}`)         | CEL (`${{expression}}`)                                 |
| ------------ | --------------------------------- | ------------------------------------------------------- |
| **Purpose**  | Simple variable substitution      | Logic and computation                                   |
| **Use when** | Displaying field values           | Conditional logic, calculations, transformations        |
| **Example**  | `{{incident.severity}}`           | `${{incident.severity == "0" ? "CRITICAL" : "Normal"}}` |
| **Output**   | String only                       | Any type (string, number, boolean, etc.)                |
| **Mixing**   | Cannot mix with CEL in same field | Cannot mix with Mustache in same field                  |

**Decision criteria:**

* Use **Mustache** for simple variable display and basic text substitution
* Use **CEL** when you need conditional logic, regex matching, calculations, or string transformations

{% hint style="warning" %}
**IMPORTANT**

You cannot mix CEL and Mustache syntax in the same field. Each field uses either `${{cel}}` or `{{mustache}}`, not both. Different fields in the same runbook can use different expression modes.
{% endhint %}

Go to [CEL Expressions in AI SRE](/ai-sre/ai-sre-for-administrators/get-started/expression-languages.md) for complete CEL syntax reference and advanced examples.

Go to [Use System Fields in Runbook Actions](/ai-sre/ai-sre-for-administrators/set-up-runbook-management/workflows/use-system-fields-in-runbook-actions.md) for a complete reference of available incident, alert, and activity fields.

***

### Next steps <a href="#next-steps" id="next-steps"></a>

Learn how to use incident and alert data in your runbook actions for dynamic automation.

* Go to [Use System Fields in Runbook Actions](/ai-sre/ai-sre-for-administrators/set-up-runbook-management/workflows/use-system-fields-in-runbook-actions.md) to learn about available system fields.
* Go to [Use Mustache Templates in Runbook Actions](/ai-sre/ai-sre-for-administrators/set-up-runbook-management/workflows/use-mustache-runbook-actions.md) to reference incident data with Mustache templates.
* Go to [Use CEL in Runbook Actions](/ai-sre/ai-sre-for-administrators/set-up-runbook-management/workflows/use-cel-runbook-actions.md) to implement dynamic logic with CEL expressions.
* Go to [Best Practices](/ai-sre/ai-sre-for-administrators/set-up-runbook-management/workflows/best-practices.md) for field usage guidelines.

{% hint style="info" %}
**Need Help?** Contact our support team by email at **<support@harness.io>** or visit the [Harness Documentation](https://docs.harness.io) for additional resources and troubleshooting guides.
{% endhint %}