GitHub Action

The mcpb-pack GitHub Action automates the entire publishing workflow.

Basic Usage

Add to .github/workflows/release.yml:

name: Release
on:
  release:
    types: [published]

permissions:
  contents: write   # Upload to releases
  id-token: write   # OIDC authentication with registry

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: NimbleBrainInc/mcpb-pack@v2

What It Does

When triggered by a GitHub release:

1. Detects your server type from manifest.json
2. Vendors all dependencies (pip/npm)
3. Packages everything into a .mcpb file
4. Uploads the bundle to your GitHub release
5. Announces to mpak.dev with OIDC authentication

Inputs

Input	Default	Description
directory	.	Directory containing manifest.json
output	{name}-{version}.mcpb	Output filename
python-version	3.13	Python version for vendoring
build	true	Whether to build the bundle
upload	true	Whether to upload to GitHub release
announce	true	Whether to register with mpak.dev
announce-url	https://registry.mpak.dev/v1/bundles/announce	Registry endpoint

Outputs

Output	Description
bundle-path	Path to the generated .mcpb file
bundle-size	Size in bytes
bundle-sha256	SHA256 hash
announced	Whether registration succeeded

Examples

Build Only (No Publish)

For testing or private servers:

- uses: NimbleBrainInc/mcpb-pack@v2
  with:
    upload: false
    announce: false

Custom Output Path

- uses: NimbleBrainInc/mcpb-pack@v2
  with:
    output: "my-server-{version}.mcpb"

Subdirectory

If your manifest.json is in a subdirectory:

- uses: NimbleBrainInc/mcpb-pack@v2
  with:
    directory: ./packages/my-server

Manual Re-announce

To re-announce after a failed registration:

on:
  release:
    types: [published]
  workflow_dispatch:
    inputs:
      build:
        description: 'Build bundle'
        type: boolean
        default: true
      announce:
        description: 'Announce to registry'
        type: boolean
        default: true

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: NimbleBrainInc/mcpb-pack@v2
        with:
          build: ${{ inputs.build }}
          announce: ${{ inputs.announce }}

OIDC Authentication

The action uses GitHub OIDC tokens to authenticate with the registry.

This means:

• No API keys - Authentication is automatic
• Provenance - The registry knows exactly which repo published the bundle
• Scope enforcement - Your package scope must match your GitHub org/username

Required Permissions

permissions:
  contents: write   # Upload to releases
  id-token: write   # OIDC token for registry

Supported Runtimes

Runtime	Detection	Dependency Vendoring
Python	server.type: "python"	uv pip install --target deps/
Node.js	server.type: "node"	npm install --omit=dev
Binary	server.type: "binary"	None (you build the binary)

Next Steps

Multi-Platform BuildsBuild for macOS, Linux, ARM, and x64