---
title: Update
description: Update the pull request branch with its base branch.
---

The `update` action instructs Mergify to update the pull request branch with
its base branch.

<Image src={updateBranchScreenshot} alt="Mergify Branch Update" />

When this action is added to a rule, Mergify will update the pull request
branch with the latest changes from its base branch, if necessary. This is done
by merging the base branch into the pull request branch.

:::note
  You do not need to use this action if you use the [merge
  queue](/merge-queue). The merge queue automatically update the pull requests
  it processes as necessary, making sure they are tested with up-to-date code
  before being merged.
:::

## Parameters

| Key name | Value type | Default | Description |
| --- | --- | --- | --- |
| `bot_account` | template or null | `null` | Mergify can impersonate a GitHub user to update a pull request. If no `bot_account` is set, Mergify will update the pull request itself. |

## Examples

### Update When Behind

You can ask Mergify to update your pull requests when they are a few commits
behind their base branch, for example:

```yaml
pull_request_rules:
  - name: automatic update of pull requests where more 5 commits behind
    conditions:
      - base = main
      - "#commits-behind > 5"
    actions:
      update:
```

### Linear History

As GitHub supports linear history in pull request settings, it is very handy to
use a rule to keep your pull requests up-to-date. As you do not want to trigger
your CI too often by always re-running it on every pull request — especially
when there is still work in progress — you can limit this action to labeled
pull requests.

```yaml
pull_request_rules:
  - name: automatic update for PR marked as “keep-up-to-date“
    conditions:
      - -draft # filter-out draft PRs
      - label = keep-up-to-date
    actions:
      update:
```

When a pull request is not a draft, and has the label `keep-up-to-date`, it
will be automatically updated with its base branch.