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

# Cross Repo Context

> Create Repo Clusters so Greptile can read related repositories as context during reviews.

Repo Clusters let you group related repositories so that whenever Greptile reviews a PR in one of them, it automatically reads the others as read-only context.

It's the dashboard equivalent of the `context.repos` field in [greptile.json](/docs/code-review/greptile-json-reference#cross-repository-context), but instead of pointing one repo at others, you define a group once and every member shares context with every other member.

Clusters are useful when a set of repos are tightly coupled, for example a service, its SDK, and its shared types, where a change in one often can't be reviewed well without the others.

### Creating a cluster

<Steps>
  <Step title="Open Cross-repo context">
    On the [Greptile dashboard](https://app.greptile.com), go to **Memory → Cross-repo context**. Managing clusters requires admin access.
  </Step>

  <Step title="Start a new cluster">
    Click **Create Repo Cluster**.

    <Frame>
      <img src="https://mintcdn.com/greptile/Y8YwftlC0YkMide_/images/new-repo-cluster.png?fit=max&auto=format&n=Y8YwftlC0YkMide_&q=85&s=9a9e4112b5dfa9eeec663202ad3957b3" alt="New repo cluster form with name and member repositories" width="2524" height="1650" data-path="images/new-repo-cluster.png" />
    </Frame>
  </Step>

  <Step title="Name the cluster">
    Give the cluster a name.
  </Step>

  <Step title="Add repositories">
    Add at least 2 repositories. A cluster can hold up to 20 GB of repositories by total size.
  </Step>
</Steps>

### Suggested clusters

Greptile suggests clusters for you based on shared contributors, meaning repositories the same people have committed to over the last 90 days. Suggestions appear with a confidence indicator; click **Use this** to create the cluster, or **Discard** to dismiss it.

### How clusters affect reviews

When Greptile reviews a PR in a clustered repo, it clones the other members read-only and makes them available to the reviewer, exactly like `context.repos`. Repos listed explicitly in `context.repos` take priority.