> ## Documentation Index
> Fetch the complete documentation index at: https://docs.0mcp.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Versioning

> Publish changes with confidence.

Every time you make changes to your MCP server, 0mcp saves them as a **version**. A version is a snapshot of your server's configuration, including its [tools](/capabilities/tools), [resources](/capabilities/resources), and [prompts](/capabilities/prompts).

Only one version can be **published** at a time, and all connected MCP clients interact with that published version.

<Info>
  Draft changes do not affect connected clients. Your MCP endpoint continues using the current published version until you publish another one.
</Info>

## Draft vs. published

Changes you make are first saved as a **draft**.

Your live MCP endpoint continues serving the current published version until you explicitly publish a new one.

This allows you to review, test, and refine changes without affecting existing clients.

## Publishing a version

When you're ready to make changes available:

1. Open **Versions**.
2. Review the version summary and validation results.
3. Publish the version.

Once published, it becomes the live configuration for your MCP server.

Clients discover the updated capabilities the next time they reconnect or refresh their available tools.

<Warning>
  Test important tool changes in the [Playground](/guides/playground) before publishing them to clients that use production data.
</Warning>

## Rolling back

If a newly published version causes issues, you can quickly return to a previous version.

Simply select an earlier version and publish it again.

The selected version immediately becomes the active configuration, while your newer drafts and version history remain intact.

## Version history

Version history gives you a record of how your MCP server has evolved over time.

For each version, consider adding a short description explaining what changed, such as:

* Added customer management tools
* Updated authentication configuration
* Removed deprecated endpoints
* Fixed tool descriptions

Meaningful version notes make it easier to identify the correct version when reviewing history or performing a rollback.

## Pausing vs. versioning

Publishing controls **what** your MCP server exposes.

Pausing controls **whether** your MCP server accepts requests.

Pausing your server temporarily stops incoming MCP requests without changing the currently published version. When you resume serving, the same published version becomes available again.

<Note>
  Pausing does not create, publish, or remove a version.
</Note>