Publishing

Nucleus can publish your installers and update metadata to GitHub Releases, Amazon S3, or a generic HTTP server.

Configuration

nativeDistributions {
    publish {
        // Publish mode
        publishMode = PublishMode.Auto // Never, Auto, Always

        github {
            enabled = true
            owner = "myorg"
            repo = "myapp"
            token = System.getenv("GITHUB_TOKEN")
            channel = ReleaseChannel.Latest
            releaseType = ReleaseType.Release
        }

        // Or S3
        s3 {
            enabled = true
            bucket = "my-updates-bucket"
            region = "us-east-1"
            path = "releases"
            acl = "public-read"
        }

        // Or generic HTTP server
        generic {
            enabled = true
            url = "https://updates.example.com/releases/"
            channel = ReleaseChannel.Latest
            useMultipleRangeRequest = true
        }
    }
}

GitHub Releases

The most common publishing target. Installers and YML metadata files are uploaded as release assets.

publish {
    github {
        enabled = true
        owner = "myorg"                      // GitHub org or user
        repo = "myapp"                       // Repository name
        token = System.getenv("GITHUB_TOKEN") // Authentication token
        channel = ReleaseChannel.Latest      // Latest, Beta, Alpha
        releaseType = ReleaseType.Release    // Release, Draft, Prerelease
    }
}

Release Structure

A GitHub Release created by Nucleus contains:

v1.0.0 (Release)
├── MyApp-1.0.0-macos-arm64.dmg
├── MyApp-1.0.0-macos-amd64.dmg
├── MyApp-1.0.0-macos-universal.dmg
├── MyApp-1.0.0-windows-amd64.exe
├── MyApp-1.0.0-windows-arm64.exe
├── MyApp-1.0.0-windows.msixbundle
├── MyApp-1.0.0-linux-amd64.deb
├── MyApp-1.0.0-linux-arm64.deb
├── MyApp-1.0.0-linux-amd64.rpm
├── MyApp-1.0.0-linux-amd64.AppImage
├── latest-mac.yml          ← Auto-update metadata
├── latest.yml              ← Auto-update metadata (Windows)
└── latest-linux.yml        ← Auto-update metadata

GitHub Token

Use a GITHUB_TOKEN with contents: write permission:

# GitHub Actions — automatic token
permissions:
  contents: write

env:
  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Amazon S3

Publish to an S3 bucket for self-hosted update distribution:

publish {
    s3 {
        enabled = true
        bucket = "my-updates-bucket"
        region = "us-east-1"
        path = "releases/myapp"    // Prefix path in the bucket
        acl = "public-read"        // ACL for uploaded files
    }
}

S3 Bucket Structure

s3://my-updates-bucket/releases/myapp/
├── MyApp-1.0.0-macos-arm64.dmg
├── MyApp-1.0.0-windows-amd64.exe
├── MyApp-1.0.0-linux-amd64.deb
├── latest-mac.yml
├── latest.yml
└── latest-linux.yml

S3 Authentication

Set AWS credentials via environment variables:

export AWS_ACCESS_KEY_ID=AKIA...
export AWS_SECRET_ACCESS_KEY=...
export AWS_REGION=us-east-1

Generic HTTP Server

For self-hosted update distribution without cloud dependencies. The generic provider generates the latest-*.yml metadata files and configures the auto-updater to fetch from a base URL. You are responsible for uploading the output to your server.

publish {
    generic {
        enabled = true
        url = "https://updates.example.com/releases/"
        channel = ReleaseChannel.Latest        // Latest, Beta, Alpha
        useMultipleRangeRequest = true         // Differential downloads
    }
}

Server Structure

Upload the installer and YML files to your server:

https://updates.example.com/releases/
├── MyApp-1.0.0-macos-arm64.dmg
├── MyApp-1.0.0-windows-amd64.exe
├── MyApp-1.0.0-linux-amd64.deb
├── latest-mac.yml
├── latest.yml
└── latest-linux.yml

Any static file server (Nginx, Caddy, Apache, S3 with public access, Cloudflare R2, etc.) works — the auto-updater simply fetches <url>/latest-<platform>.yml and downloads the installer from the same base URL.

Release Channels

Channels allow you to distribute pre-release versions to testers:

Channel	YML Prefix	Version Pattern	Audience
ReleaseChannel.Latest	latest-	1.0.0	All users
ReleaseChannel.Beta	beta-	1.0.0-beta.1	Beta testers
ReleaseChannel.Alpha	alpha-	1.0.0-alpha.1	Internal testers

Users on the beta channel receive both latest and beta updates. Users on the alpha channel receive all updates.

Configure the channel in the updater runtime:

NucleusUpdater {
    provider = GitHubProvider(owner = "myorg", repo = "myapp")
    channel = "beta" // Subscribe to beta updates
}

Release Types

Type	Description
ReleaseType.Release	Visible on the releases page
ReleaseType.Draft	Hidden until manually published
ReleaseType.Prerelease	Marked as pre-release

Publish Modes

Mode	Description
PublishMode.Never	Do not publish (build only)
PublishMode.Auto	Publish if on CI, skip locally
PublishMode.Always	Always publish

DSL Reference

publish { }

Property	Type	Default	Description
publishMode	PublishMode	Never	When to publish

publish { github { } }

Property	Type	Default	Description
enabled	Boolean	false	Enable GitHub publishing
owner	String	—	GitHub owner/org
repo	String	—	Repository name
token	String?	null	GitHub token
channel	ReleaseChannel	Latest	Release channel
releaseType	ReleaseType	Release	Release type

publish { s3 { } }

Property	Type	Default	Description
enabled	Boolean	false	Enable S3 publishing
bucket	String	—	S3 bucket name
region	String	—	AWS region
path	String?	null	Key prefix
acl	String?	null	S3 ACL

publish { generic { } }

Property	Type	Default	Description
enabled	Boolean	false	Enable generic HTTP publishing
url	String	—	Base URL where update files are hosted
channel	ReleaseChannel	Latest	Release channel
useMultipleRangeRequest	Boolean	true	Use multiple range requests for differential downloads