# Continuous Integration (CI) {#continuous-integration-ci}

To use the registry on your CI, you need to ensure that you have logged in to
the registry by running `tuist registry login` as part of your workflow.

::: info ONLY XCODE INTEGRATION
<!-- -->
Creating a new pre-unlocked keychain is required only if you are using the Xcode
integration of packages.
<!-- -->
:::

Since the registry credentials are stored in a keychain, you need to ensure the
keychain can be accessed in the CI environment. Note some CI providers or
automation tools like [Fastlane](https://fastlane.tools/) already create a
temporary keychain or provide a built-in way how to create one. However, you can
also create one by creating a custom step with the following code:
```bash
TMP_DIRECTORY=$(mktemp -d)
KEYCHAIN_PATH=$TMP_DIRECTORY/keychain.keychain
KEYCHAIN_PASSWORD=$(uuidgen)
security create-keychain -p $KEYCHAIN_PASSWORD $KEYCHAIN_PATH
security set-keychain-settings -lut 21600 $KEYCHAIN_PATH
security default-keychain -s $KEYCHAIN_PATH
security unlock-keychain -p $KEYCHAIN_PASSWORD $KEYCHAIN_PATH
```

`tuist registry login` will then store the credentials in the default keychain.
Ensure that your default keychain is created and unlocked _before_ `tuist
registry login` is run.

Additionally, you need to ensure the `TUIST_TOKEN` environment variable is set.
You can create one by following the documentation
<LocalizedLink href="/guides/server/authentication#as-a-project">here</LocalizedLink>.

An example workflow for GitHub Actions could then look like this:
```yaml
name: Build

jobs:
  build:
    steps:
      - # Your set up steps...
      - name: Create keychain
        run: |
        TMP_DIRECTORY=$(mktemp -d)
        KEYCHAIN_PATH=$TMP_DIRECTORY/keychain.keychain
        KEYCHAIN_PASSWORD=$(uuidgen)
        security create-keychain -p $KEYCHAIN_PASSWORD $KEYCHAIN_PATH
        security set-keychain-settings -lut 21600 $KEYCHAIN_PATH
        security default-keychain -s $KEYCHAIN_PATH
        security unlock-keychain -p $KEYCHAIN_PASSWORD $KEYCHAIN_PATH
      - name: Log in to the Tuist Registry
        env:
          TUIST_TOKEN: ${{ secrets.TUIST_TOKEN }}
        run: tuist registry login
      - # Your build steps
```

### Incremental resolution across environments {#incremental-resolution-across-environments}

Clean/cold resolutions are slightly faster with our registry, and you can
experience even greater improvements if you persist the resolved dependencies
across CI builds. Note that thanks to the registry, the size of the directory
that you need to store and restore is much smaller than without the registry,
taking significantly less time. To cache dependencies when using the default
Xcode package integration, the best way is to specify a custom
`clonedSourcePackagesDirPath` when resolving dependencies via `xcodebuild`. This
can be done by adding the following to your `Config.swift` file:

```swift
import ProjectDescription

let config = Config(
    generationOptions: .options(
        additionalPackageResolutionArguments: ["-clonedSourcePackagesDirPath", ".build"]
    )
)
```

Additionally, you will need to find a path of the `Package.resolved`. You can
grab the path by running `ls **/Package.resolved`. The path should look
something like
`App.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved`.

For Swift packages and the XcodeProj-based integration, we can use the default
`.build` directory located either in the root of the project or in the `Tuist`
directory. Make sure the path is correct when setting up your pipeline.

Here's an example workflow for GitHub Actions for resolving and caching
dependencies when using the default Xcode package integration:
```yaml
- name: Restore cache
  id: cache-restore
  uses: actions/cache/restore@v4
  with:
    path: .build
    key: ${{ runner.os }}-${{ hashFiles('App.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved') }}
- name: Resolve dependencies
  if: steps.cache-restore.outputs.cache-hit != 'true'
  run: xcodebuild -resolvePackageDependencies -clonedSourcePackagesDirPath .build
- name: Save cache
  id: cache-save
  uses: actions/cache/save@v4
  with:
    path: .build
    key: ${{ steps.cache-restore.outputs.cache-primary-key }}
```