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# How versioning works with assistants and tools

> Select a specific or latest tool version for an assistant, and learn how restoring an assistant also restores the tool version selections saved with it.

## How version pinning works

Assistants and tools are [versioned independently](/assistants/versioning), but an assistant configuration records which version of each tool to use. You can select a numbered version or **Current**, which appears as **Latest** when the menu is closed. When you publish the assistant, Vapi saves those selections in the assistant version.

## Choose a tool version in the Dashboard

#### Open the assistant

Open the [Dashboard](https://dashboard.vapi.ai), select **Assistants**, and select the assistant that uses the tool.

#### Open the Tools tab

Select **Tools**.

#### Choose the tool version

Under **Assign Tool Version**, open the version menu for the tool. Choose one of these options:

* **Current**: Always use the tool's current version. The closed menu displays **Latest**.
* **Numbered version**: Pin the assistant to a specific version, such as **v3**. The assistant stays on that version until you change the selection and publish the assistant again.

![Jamie assistant Tools tab with the Assign Tool Version menu open for a transfer call tool](/_fern-img/4dd903b3a9604388e4e53ff2455a5a88b5c676732b2fd6bad3dde0477cba9ab3.webp)

#### Publish the assistant

Select **Publish** and complete the publish flow to save the tool version selection in a new assistant version.

## Use the latest tool version through the API

When you [create](/api-reference/assistants/create) or [update](/api-reference/assistants/update) an assistant through the API, omit the tool version to use **Latest**. The assistant then uses the newest published version of that tool.

## How restoring an assistant affects tools

When you restore an assistant version, Vapi immediately creates a new current assistant version with its saved tool version selections. A specific tool version returns to the saved selection. A tool set to **Latest** continues to use its newest published version.

For example:

* At **v6**, the assistant uses **Tool A v4** and **Tool B v6**.
* The assistant's **v5** configuration used **Tool A v2** and **Tool B v4**.
* You restore assistant **v5**. Vapi creates assistant **v7**, makes it current, and restores the selections for Tool A v2 and Tool B v4.
* If Tool B was set to **Latest** in assistant v5, it continues to use the newest published Tool B version.

## Next steps

#### [Versioning overview](/assistants/versioning)

Save, publish, and restore versions of your assistants and tools.

#### [Versioning with assistants](/assistants/versioning/versioning-assistants)

Publish, view history, and restore versions of an assistant.

#### [Versioning with tools](/assistants/versioning/versioning-tools)

Publish, view history, and restore versions of a tool.