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

# Version Management

> How image tags and deployment versions work, and how to inspect, activate, and roll back versions.

Every `zeroruntime up` produces two things:

* An **image tag**, `<agent-id>:vX.Y`: the Docker image that was built.
* A **version**, `vr_…`: the immutable deployment record that runs that image.

`zeroruntime version` commands take the `vr_…` ID, not the image tag.

## Image tags

You don't name images. Each `up` builds the **next** tag after the one recorded in
`build.image` in `zeroruntime.yaml`, starting at `v0.0`. `X` can be any number and `Y` is a single
digit, so `v0.9` is followed by `v1.0`.

```
v0.0 → v0.1 → … → v0.9 → v1.0 → v1.1 → …
```

```bash theme={null}
zeroruntime up                                    # next tag, e.g. my-agent:v0.1
zeroruntime up --version v1.0                     # jump ahead to my-agent:v1.0
zeroruntime up --skip-build --image my-agent:v0.3 # redeploy an image you already built
```

<Note>
  A tag can jump ahead but never go back. `up` rejects a version lower than or equal to the
  last one built and names the next valid one. `--version` applies only when building; with
  `--skip-build`, use `--image <agent-id>:vX.Y`.
</Note>

## Inspect versions

```bash theme={null}
zeroruntime version list                          # all versions, active one marked
zeroruntime version describe                        # rollout state of the latest version
zeroruntime version describe -v <version-id>      # full details for one version
```

## Activate and roll back

Make any version live, including an older one to roll back:

```bash theme={null}
zeroruntime version activate -v <version-id>
```

To take a single version offline, see [Scaling Down](/deployments/operate/scaling-down).


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