# How to Configure Dewy to Use GitHub Releases as a Registry > Configure Dewy to use GitHub Releases as a registry with the ghr:// scheme. Easily control version selection using query parameters for seamless integration. - Repository: [Tomohisa Oda/dewy](https://github.com/linyows/dewy) - Tags: how-to-guide - Published: 2026-03-06 --- **To configure Dewy to use GitHub Releases as a registry, pass a URL with the `ghr://` scheme using the `--registry` flag or `DEWY_REGISTRY` environment variable, optionally appending query parameters like `?pre-release=true` or `?artifact=` to control version selection.** Dewy is an open-source deployment tool that supports multiple artifact registries through a unified URL syntax. When you configure Dewy to use GitHub Releases, it can automatically resolve the latest tags, download specific assets, and deploy them without manual intervention. This guide explains the exact syntax, internal resolution logic, and practical examples based on the `linyows/dewy` source code. ## Understanding the GitHub Releases Registry Scheme Dewy identifies GitHub Releases using the **`ghr://`** URL scheme. In [`registry/registry.go`](https://github.com/linyows/dewy/blob/main/registry/registry.go), the scheme is defined as a constant that routes incoming requests to the GitHub Releases implementation. ### Registry URL Format The standard format follows this pattern: ```bash ghr:/// ``` You can optionally append query parameters to customize artifact selection. The URL parsing logic in [`registry/registry.go`](https://github.com/linyows/dewy/blob/main/registry/registry.go) (lines 61-80) strips the scheme and extracts the repository owner and name before delegating to the GitHub Releases handler. ### Supported Query Parameters The GitHub Releases implementation in [`registry/ghr.go`](https://github.com/linyows/dewy/blob/main/registry/ghr.go) (lines 70-78) recognizes two key query parameters: - **pre-release**: Set to `true` to include pre-release versions in the search - **artifact**: Specify a custom asset name to download instead of the default ## Setting the Registry via CLI and Environment Variables The registry URL is supplied to Dewy through the **`--registry`** flag defined in [`cli.go`](https://github.com/linyows/dewy/blob/main/cli.go) (line 41). Alternatively, you can use the **`DEWY_REGISTRY`** environment variable to configure the endpoint declaratively. ```bash # Using the CLI flag dewy server --registry ghr://linyows/myapp # Using environment variable export DEWY_REGISTRY=ghr://linyows/myapp dewy server ``` ## How Dewy Resolves GitHub Releases Internally When configured with a `ghr://` URL, Dewy instantiates a **GHR** object that interacts directly with the GitHub API to resolve tags and download artifacts. ### URL Parsing and Scheme Detection In [`registry/registry.go`](https://github.com/linyows/dewy/blob/main/registry/registry.go) (line 16), the registry handler maintains a registry of supported schemes. When it encounters the `ghr` scheme, it initializes the GitHub Releases provider and passes the sanitized repository path to the constructor. ### Artifact Resolution and Download The concrete implementation in [`registry/ghr.go`](https://github.com/linyows/dewy/blob/main/registry/ghr.go) performs three critical operations: 1. **Tag Resolution**: Queries the GitHub API to find the latest release (or latest pre-release if specified via query parameter) 2. **Asset Filtering**: Locates the specified artifact by name using the `artifact` query parameter 3. **Download Generation**: Constructs the authenticated download URL (line 158) to fetch the binary securely ## Complete Configuration Examples ### Server Deployment Examples Deploy a server using the latest stable release from a GitHub repository: ```bash dewy server --registry ghr://linyows/myapp \ --slot blue -- /opt/myapp/current/myapp ``` Deploy using a pre-release version and a specific asset file: ```bash dewy server --registry "ghr://linyows/myapp?pre-release=true&artifact=dewy.tar" \ --slot blue -- /opt/myapp/current/myapp ``` ### Asset Download Examples Download frontend assets from a GitHub Release to a specific directory: ```bash dewy assets --registry ghr://linyows/frontend \ -d /var/www/html \ -l info ``` This pattern corresponds to the example found in the README (line 69). ## Summary - Use the **`ghr://`** scheme to configure GitHub Releases as your Dewy registry - Pass the URL via **`--registry`** flag or **`DEWY_REGISTRY`** environment variable - Append **`?pre-release=true`** to target pre-release versions instead of stable releases - Specify **`?artifact=`** to download a specific asset from the release - Dewy handles resolution logic in [`registry/ghr.go`](https://github.com/linyows/dewy/blob/main/registry/ghr.go) and URL routing in [`registry/registry.go`](https://github.com/linyows/dewy/blob/main/registry/registry.go) ## Frequently Asked Questions ### What URL scheme does Dewy use for GitHub Releases? Dewy uses the **`ghr://`** scheme to identify GitHub Releases registries. This constant is defined in [`registry/registry.go`](https://github.com/linyows/dewy/blob/main/registry/registry.go) (line 16) and triggers the GitHub-specific resolution logic implemented in [`registry/ghr.go`](https://github.com/linyows/dewy/blob/main/registry/ghr.go) when parsed. ### Can I filter for pre-release versions? Yes. Append **`?pre-release=true`** to your registry URL. The [`registry/ghr.go`](https://github.com/linyows/dewy/blob/main/registry/ghr.go) file (lines 70-78) decodes this parameter and includes pre-releases when querying the GitHub API for the latest tag, allowing you to deploy bleeding-edge builds. ### How do I specify a custom artifact name? Use the **`artifact`** query parameter in your registry URL, such as `ghr://owner/repo?artifact=myapp-linux-amd64.tar.gz`. If omitted, Dewy relies on its default asset resolution logic to select the appropriate file from the release. ### Is the registry URL configurable via environment variables? Yes. While the `--registry` flag defined in [`cli.go`](https://github.com/linyows/dewy/blob/main/cli.go) (line 41) provides CLI access, Dewy also respects the **`DEWY_REGISTRY`** environment variable, allowing you to configure the GitHub Releases endpoint without modifying startup scripts or systemd service files.