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

# Agent Versioning

> Publish immutable snapshots of your agent configuration, pin versions to channels, and track changes over time.

# Agent Versioning

Agent versioning lets you capture the full configuration of an agent at a point in time, creating an **immutable snapshot** you can deploy, compare, or restore later. This is essential for production deployments where you need reproducibility and safe rollbacks.

## Concepts

| Concept               | Description                                                                                                                              |
| --------------------- | ---------------------------------------------------------------------------------------------------------------------------------------- |
| **Draft**             | The live, editable configuration of your agent. Changes are immediate. This is what you work with in the agent editor.                   |
| **Published version** | An immutable snapshot of the agent's full configuration at a specific moment. Once published, it cannot be modified.                     |
| **Version number**    | Auto-incrementing integer (V1, V2, V3...) assigned when you publish.                                                                     |
| **Version pinning**   | Deploying a specific published version to a channel (phone number), so production calls use a frozen configuration instead of the draft. |

<Info>
  The draft is always your working copy. Publishing a version does not affect the draft — you can continue editing freely after publishing.
</Info>

***

## What Is Included in a Version

A published version captures the complete agent state:

| Component                                           | Included |
| --------------------------------------------------- | -------- |
| Agent name                                          | Yes      |
| System prompt and welcome message                   | Yes      |
| LLM provider, model, temperature, max tokens        | Yes      |
| TTS voice, STT provider, language                   | Yes      |
| Interruption, turn context, inactivity settings     | Yes      |
| Background sound configuration                      | Yes      |
| Linked knowledge bases (IDs and retrieval settings) | Yes      |
| Linked tools (full tool configuration)              | Yes      |
| Call analysis fields and prompt                     | Yes      |
| Workflow JSON (for workflow agents)                 | Yes      |

***

## Publishing a Version

<Steps>
  <Step title="Open the agent">
    Navigate to **Build > Agents** and select the agent you want to version.
  </Step>

  <Step title="Click Save Version">
    In the agent editor header, click the **Save Version** button.
  </Step>

  <Step title="Name and describe">
    Enter a **version name** (e.g. "Production v1", "Post-holiday update") and an optional description explaining what changed.
  </Step>

  <Step title="Publish">
    Click **Save**. The version is created with the next available version number.
  </Step>
</Steps>

<Warning>
  Published versions are immutable. You cannot edit a published version. To make changes, edit the draft and publish a new version.
</Warning>

***

## Version History

Click the **version history** button in the agent editor header to open the version history panel. It shows:

* The current **Draft** at the top
* All published versions in reverse chronological order
* For each version: version number, name, description, author, and publication date

***

## Restoring a Version

If you need to revert the draft to a previous configuration:

<Steps>
  <Step title="Open version history">
    Click the version history button in the agent editor.
  </Step>

  <Step title="Select a version">
    Find the version you want to restore.
  </Step>

  <Step title="Click Restore">
    Click the **Restore** button on the version. The agent's draft configuration is overwritten with the snapshot data.
  </Step>
</Steps>

<Info>
  Restoring a version overwrites the current draft. If you want to preserve the current draft, publish it as a new version before restoring.
</Info>

***

## Version Pinning (Channels)

By default, phone numbers use the agent's **draft** configuration. For production stability, you can pin a phone number to a specific published version.

1. Navigate to **Deploy > Channels**
2. On the phone number, select an agent
3. Use the **version dropdown** next to the agent selector to choose a published version (or leave it on "Draft")
4. Save the configuration

When a version is pinned, incoming calls on that number use the frozen snapshot — even if you continue editing the draft.

<Tip>
  Use version pinning for production numbers and keep the draft for development and testing. This lets you iterate safely without affecting live calls.
</Tip>

### Version Pinning with A/B Testing

When running an [A/B test](/deploy/channels#ab-testing-weighted-agent-routing), each variant can be pinned to a different version independently. For example:

| Variant | Agent       | Version            | Weight |
| ------- | ----------- | ------------------ | ------ |
| Control | Sales Agent | V3 (stable)        | 80%    |
| Test    | Sales Agent | Draft (new prompt) | 20%    |

***

## Filtering by Version

Published versions integrate with monitoring and analytics:

* **Monitor > Calls**: filter the call list by version number to see only calls handled by a specific version
* **Monitor > Analytics**: version filter available on dashboards to compare performance across versions

This makes it easy to measure the impact of configuration changes on real call data.

***

## Best Practices

<AccordionGroup>
  <Accordion title="Publish before deploying to production">
    Always publish a version and pin it to your production number before going live. This ensures calls are not affected by subsequent edits to the draft.
  </Accordion>

  <Accordion title="Use descriptive version names">
    Names like "V1" are less useful than "Added appointment booking tool" or "French prompt rewrite". A good name tells you what changed without opening the snapshot.
  </Accordion>

  <Accordion title="Compare versions via call analytics">
    After deploying a new version, use the version filter in Analytics to compare metrics (call duration, sentiment, automation rate) between the old and new versions.
  </Accordion>
</AccordionGroup>