Flox Package Publishing Guide

Flox Package Publishing Guide

Core Commands

flox publish                    # Publish all packages
flox publish my_package         # Publish single package
flox publish -o myorg package   # Publish to organization
flox publish -o myuser package  # Publish to personal namespace
flox auth login                 # Authenticate before publishing

Publishing Workflow: Development to Runtime

Publishing packages enables a clear separation between development and runtime/​consumption:

The Complete Workflow

Phase 1: Development Environment

# .flox/​env/​manifest.toml (in git with source code)
[install]
gcc.pkg-path = "gcc13"
make.pkg-path = "make"
python.pkg-path = "python311Full"

[build.myapp]
command = '''
  python setup.py build
  mkdir -p $out/​bin
  cp build/​myapp $out/​bin/
'''
version = "1.0.0"

Developers work in this environment, commit .flox/ to git alongside source code.

Phase 2: Build and Publish

# Build the package
flox build myapp

# Publish to catalog
flox publish -o myorg myapp

The published package contains BINARIES/​ARTIFACTS (what's in $out/), NOT source code.

Phase 3: Runtime Environment

# Separate environment (can be pushed to FloxHub)
[install]
myapp.pkg-path = "myorg/​myapp"  # The published package

Consumers create runtime environments and install the published package. No build tools needed, no source code exposed.

Key insight: You don't install the published package back into the development environment - that would be circular. Published packages are installed into OTHER environments (different projects, production, etc.).

Publishing to Flox Catalog

Prerequisites

Before publishing:

• Package defined in [build] section or .flox/​pkgs/
• Environment in Git repo with configured remote
• Clean working tree (no uncommitted changes)
• Current commit pushed to remote
• All build files tracked by Git
• At least one package installed in [install]

Authentication

Run authentication before first publish:

flox auth login

Publishing Commands

# Publish single package
flox publish my_package

# Publish all packages
flox publish

# Publish to organization
flox publish -o myorg my_package

# Publish to personal namespace (for testing)
flox publish -o mypersonalhandle my_package

Catalog Types

Personal catalogs: Only visible to you (good for testing)

• Published to your personal namespace
• Example: User "alice" publishes "hello" → available as alice/​hello
• Useful for testing before publishing to organization

Organization catalogs: Shared with team members (paid feature)

• Published to organization namespace
• Example: Org "acme" publishes "tool" → available as acme/​tool
• All organization members can install

Build Validation

Flox clones your repo to a temp location and performs a clean build to ensure reproducibility. Only packages that build successfully in this clean environment can be published.

This validation ensures:

• All dependencies are declared
• Build is reproducible
• No reliance on local machine state
• Git repository is clean and up-to-date

After Publishing

• Package available in flox search, flox show, flox install
• Metadata sent to Flox servers
• Package binaries uploaded to Catalog Store
• Install with: flox install <catalog>/<package>

Users can then:

# Search for your package
flox search my_package

# See package details
flox show myorg/​my_package

# Install the package
flox install myorg/​my_package

What Gets Published

Published packages contain:

• Binaries and compiled artifacts (everything in $out/)
• Runtime dependencies specified in runtime-packages
• Package metadata (version, description)

Published packages do NOT contain:

• Source code (unless explicitly copied to $out/)
• Build tools or build-time dependencies
• Development environment configuration
• The .flox/ directory itself

This separation allows you to share built artifacts without exposing source code.

Real-world Publishing Workflows

Application Development Workflow

Developer workflow:

1. Create development environment with build tools:

   mkdir myapp && cd myapp
   flox init
   flox install gcc make python311Full
   

2. Add source code and build definition to .flox/​env/​manifest.toml:

   [build.myapp]
   command = '''make && cp myapp $out/​bin/'''
   version = "1.0.0"
   

3. Commit to git (environment definition + source code):

   git add .flox/ src/
   git commit -m "Add development environment and source"
   git push origin main
   

4. Build and publish package (binaries/​artifacts):

   flox build myapp
   flox publish -o myorg myapp
   

Other developers:

• Clone repo: git clone <repo> && cd myapp && flox activate
• Get the same development environment with build tools

Consumers:

• Create new runtime environment: flox init && flox install myorg/​myapp
• OR install into existing environment: flox install myorg/​myapp
• Get the BUILT package (binaries), not source code
• Can push runtime environment to FloxHub without exposing source

Fork-based Development Pattern

1. Fork upstream repo (e.g., user/​project from upstream/​project)
2. Add .flox/ to fork with build definitions
3. Commit and push: git push origin main
4. Publish package: flox publish -o username package-name
5. Others can install: flox install username/​package-name

Versioning Strategies

Semantic Versioning

[build.mytool]
version = "1.2.3"  # Major.Minor.Patch
description = "My awesome tool"

Git-based Versioning

[build.mytool]
version.command = "git describe --tags"
description = "My awesome tool"

File-based Versioning

[build.mytool]
version.file = "VERSION.txt"
description = "My awesome tool"

Dynamic Versioning from Source

[build.rustapp]
version.command = "cargo metadata --no-deps --format-version 1 | jq -r '.packages[0].version'"

Publishing Multiple Variants

You can publish multiple variants of the same project:

[build.myapp]
command = '''
  cargo build --release
  mkdir -p $out/​bin
  cp target/​release/​myapp $out/​bin/
'''
version = "1.0.0"
description = "Production build"
sandbox = "pure"

[build.myapp-debug]
command = '''
  cargo build
  mkdir -p $out/​bin
  cp target/​debug/​myapp $out/​bin/​myapp-debug
'''
version = "1.0.0"
description = "Debug build with symbols"
sandbox = "off"

Both can be published and users can choose which to install.

Testing Before Publishing

Local Testing

1. Build the package:

flox build myapp

1. Test the built artifact:

./​result-myapp/​bin/​myapp --version

1. Install locally to test:

flox install ./​result-myapp

Personal Catalog Testing

Publish to your personal namespace first:

flox publish -o myusername myapp

Then test installation:

flox install myusername/​myapp

Once validated, republish to organization:

flox publish -o myorg myapp

Common Gotchas

Branch names

Many repos use master not main - check with git branch

Auth required

Run flox auth login before first publish

Clean git state

Commit and push ALL changes before flox publish:

git status  # Check for uncommitted changes
git add .flox/
git commit -m "Add flox build configuration"
git push origin master

runtime-packages

List only what package needs at runtime, not build deps:

[install]
gcc.pkg-path = "gcc"
make.pkg-path = "make"

[build.myapp]
command = '''make && cp myapp $out/​bin/'''
runtime-packages = []  # No runtime deps needed

Git-tracked files only

All files referenced in build must be tracked:

git add .flox/​pkgs/​*
git add src/
git commit -m "Add build files"

Publishing Nix Expression Builds

For Nix expression builds in .flox/​pkgs/:

1. Create the Nix expression:

mkdir -p .flox/​pkgs
cat > .flox/​pkgs/​hello.nix << 'EOF'
{ hello }:
hello.overrideAttrs (oldAttrs: {
  patches = (oldAttrs.patches or []) ++ [ ./​my.patch ];
})
EOF

1. Track with Git:

git add .flox/​pkgs/​*
git commit -m "Add hello package"
git push

1. Publish:

flox publish hello

Publishing Configuration and Assets

You can publish non-code artifacts:

Configuration templates

[build.nginx-config]
command = '''
  mkdir -p $out/​etc
  cp nginx.conf $out/​etc/
  cp -r conf.d $out/​etc/
'''
version = "1.0.0"
description = "Organization Nginx configuration"

Protocol buffers

[build.api-proto]
command = '''
  mkdir -p $out/​share/​proto
  cp proto/​**/​*.proto $out/​share/​proto/
'''
version = "2.1.0"
description = "API protocol definitions"

Teams install and reference via $FLOX_ENV/​etc/ or $FLOX_ENV/​share/.

Continuous Integration Publishing

GitHub Actions Example

name: Publish to Flox

on:
  push:
    tags:
      - 'v*'

jobs:
  publish:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/​checkout@v3

      - name: Install Flox
        run: |
          curl -fsSL https://downloads.flox.dev/​by-env/​stable/​install | bash

      - name: Authenticate
        env:
          FLOX_AUTH_TOKEN: ${{ secrets.FLOX_AUTH_TOKEN }}
        run: flox auth login --token "$FLOX_AUTH_TOKEN"

      - name: Publish package
        run: flox publish -o myorg mypackage

GitLab CI Example

publish:
  stage: deploy
  only:
    - tags
  script:
    - curl -fsSL https://downloads.flox.dev/​by-env/​stable/​install | bash
    - flox auth login --token "$FLOX_AUTH_TOKEN"
    - flox publish -o myorg mypackage

Package Metadata Best Practices

Good Descriptions

[build.cli]
description = "High-performance log shipper with filtering"  # Good: specific, descriptive

# Avoid:
# description = "My tool"  # Too vague
# description = "CLI"      # Not descriptive enough

Proper Versioning

• Use semantic versioning: MAJOR.MINOR.PATCH
• Increment MAJOR for breaking changes
• Increment MINOR for new features
• Increment PATCH for bug fixes

Runtime Dependencies

Only include what's actually needed at runtime:

[install]
# Build-time only
gcc.pkg-path = "gcc"
make.pkg-path = "make"
# Runtime dependency
libssl.pkg-path = "openssl"

[build.myapp]
runtime-packages = ["libssl"]  # Only runtime deps

Related Skills

• flox-builds - Building packages before publishing, dual-environment workflow
• flox-environments - Setting up development and runtime environments
• flox-sharing - Sharing environment definitions (via git or FloxHub) vs publishing packages (binaries/​artifacts)