docs(build-distribution): Add Install Groups documentation

docs/platforms/android/build-distribution/install-groups.mdx

@@ -0,0 +1,60 @@
+---
+title: Install Groups
+sidebar_order: 20
+description: Control which Android builds can see updates for each other using install groups.
+---
+
+<Include name="feature-available-for-user-group-early-adopter" />
+
+Install groups let you tag builds with one or more group names to control update visibility between builds. See the [product documentation](/product/build-distribution/#install-groups) for a full explanation of how install groups work.
+
+## Uploading With Install Groups
+
+### Sentry CLI
+
+Pass `--install-group` one or more times:
+
+```bash
+sentry-cli build upload app.apk \
+  --org your-org \
+  --project your-project \
+  --build-configuration Release \
+  --install-group alpha \
+  --install-group staging
+```
+
+### Gradle Plugin
+
+Set `installGroups` in the `distribution` block:
+
+```kotlin {filename:build.gradle.kts}
+sentry {
+  distribution {
+    enabled = true
+    installGroups.set(setOf("alpha", "staging"))
+  }
+}
+```
+
+```groovy {filename:build.gradle}
+sentry {
+  distribution {
+    enabled = true
+    installGroups = ["alpha", "staging"]
+  }
+}
+```
+
+### Fastlane Plugin
+
+Pass the `install_groups` parameter:
+
+```ruby {filename:Fastfile}
+sentry_upload_build(
+  org_slug: 'your-org',
+  project_slug: 'your-project',
+  apk_path: 'path/to/app.apk',
+  build_configuration: 'Release',
+  install_groups: ['alpha', 'staging']
+)
+```

docs/platforms/apple/guides/ios/build-distribution/install-groups.mdx

@@ -0,0 +1,38 @@
+---
+title: Install Groups
+sidebar_order: 20
+description: Control which iOS builds can see updates for each other using install groups.
+---
+
+<Include name="feature-available-for-user-group-early-adopter" />
+
+Install groups let you tag builds with one or more group names to control update visibility between builds. See the [product documentation](/product/build-distribution/#install-groups) for a full explanation of how install groups work.
+
+## Uploading With Install Groups
+
+### Sentry CLI
+
+Pass `--install-group` one or more times:
+
+```bash
+sentry-cli build upload app.xcarchive \
+  --org your-org \
+  --project your-project \
+  --build-configuration Release \
+  --install-group alpha \
+  --install-group staging
+```
+
+### Fastlane Plugin
+
+Pass the `install_groups` parameter:
+
+```ruby {filename:Fastfile}
+sentry_upload_build(
+  org_slug: 'your-org',
+  project_slug: 'your-project',
+  xcarchive_path: 'path/to/YourApp.xcarchive',
+  build_configuration: 'Release',
+  install_groups: ['alpha', 'staging']
+)
+```

docs/product/build-distribution/index.mdx

@@ -25,6 +25,29 @@ Below is the metadata included in your build, regardless of the platform.
 
 <Include name="size-analysis/upload-metadata" />
 
+## Install Groups
+
+Install groups let you tag builds with one or more group names to control update visibility. When a device checks for updates, you can provide a list of install groups — only builds that share at least one install group with this list will be returned as available updates.
+
+This is useful when you have multiple distribution channels (for example, separate branches, teams, or rollout stages) and want to prevent builds from one channel from being offered as updates to another.
+
+### How It Works
+
+When you upload a build, you can assign one or more install groups to it. If the Auto-Update SDK is provided install groups, it only returns builds that have overlapping groups.
+
+Matching requires two builds to have a non-empty intersection of their install groups. For example, a build tagged `["alpha", "staging"]` will see updates from a build tagged `["alpha", "beta"]` because both share `alpha`.
+
+### Use Cases
+
+- **Branch-based testing**: Tag CI builds with the branch name so developers only receive updates from their own branch.
+- **Staged rollouts**: Use groups like `"alpha"`, `"beta"`, and `"internal"` to control which teams receive which builds.
+- **Team separation**: Give each team its own install group so they only see builds relevant to them.
+
+For platform-specific setup instructions, see:
+
+- [Android Install Groups](/platforms/android/build-distribution/install-groups/)
+- [iOS Install Groups](/platforms/apple/guides/ios/build-distribution/install-groups/)
+
 ## Downloading Builds
 
 <Include name="build-distribution/download" />

includes/size-analysis/upload-metadata.mdx

@@ -12,5 +12,6 @@ We use build metadata to organize builds in the UI and ensure correct comparison
 | `pr-number`             | Pull request number                                                                                       |
 | `head-ref`              | Branch or tag name                                                                                        |
 | `base-ref`              | Base branch name                                                                                          |
+| `install-group`         | [Install group(s)](/product/build-distribution/#install-groups) to control update visibility between builds. Can be specified multiple times |
 
 \* _required field_