Files
BrowserOS/packages/browseros
Nikhil 8de2bf984f feat: build linux x64 + arm64 in a single invocation (#652)
`release.linux.yaml` now declares `architecture: [x64, arm64]` and the
runner loops the entire pipeline once per architecture. depot_tools
fetches both Linux sysroots automatically — `git_setup` idempotently
ensures `target_cpus = ['x64', 'arm64']` is in `.gclient` before
`gclient sync`, so cross-compiling arm64 from an x64 host just works.

The resolver returns `List[Context]` (single-element for the common
single-arch case), and `build/cli/build.py` loops `execute_pipeline` over
the per-arch contexts. Modules stay 100% arch-agnostic — no new
orchestration module, no new YAML schema beyond the list form.

Also fix a cross-compile bug in `build/modules/package/linux.py`: the
appimagetool binary must match the BUILD machine's arch (it executes
locally), not the target arch. Split into a host-keyed
`LINUX_HOST_APPIMAGETOOL` lookup vs the existing target-keyed
`LINUX_ARCHITECTURE_CONFIG`. Target arch is still passed to appimagetool
via the `ARCH` env var.

- build/common/resolver.py: scalar OR list `architecture` -> List[Context]
- build/cli/build.py: loop pipeline per arch, log multi-arch headers
- build/config/release.linux.yaml: `architecture: [x64, arm64]`
- build/modules/setup/git.py: idempotent `target_cpus` edit on Linux
- build/modules/package/linux.py: host vs target appimagetool split
- build/modules/package/linux_test.py: cover the host/target split
2026-04-06 13:08:06 -07:00
..
2026-03-04 18:31:20 -08:00

BrowserOS Browser (Chromium Fork)

Custom Chromium build with AI agent integration, enhanced privacy patches, and native MCP support.

Based on Chromium 146.0.7680.31 · Built with Python 3.12+ · Licensed under AGPL-3.0

What This Is

This package contains the BrowserOS browser build system — everything needed to fetch Chromium source, apply BrowserOS patches, and produce signed binaries for macOS, Windows, and Linux. The build system is a Python CLI that orchestrates the entire pipeline from source to distributable.

BrowserOS patches add:

  • Native AI agent sidebar and new tab integration
  • MCP server endpoints baked into the browser
  • Enhanced privacy via ungoogled-chromium patches
  • Custom branding, icons, and entitlements
  • Keychain access group management (macOS)
  • Sparkle auto-update framework (macOS)

Prerequisites

Requirement Details
Disk space ~100 GB for Chromium source + build artifacts
Python 3.12+
macOS Xcode + Command Line Tools
Linux build-essential, clang, lld, and Chromium's Linux deps
Windows Visual Studio 2022, Windows SDK

Directory Structure

packages/browseros/
├── build/                   # Build system (Python CLI)
│   ├── __main__.py          # CLI entry point
│   ├── browseros.py         # Main app definition
│   ├── modules/
│   │   ├── setup/           # Chromium source fetch and setup
│   │   ├── patches/         # Patch application logic
│   │   ├── apply/           # Apply patches to source tree
│   │   ├── extract/         # Extract patches from modified source
│   │   ├── feature/         # Feature flag management
│   │   ├── package/         # Binary packaging
│   │   ├── sign/            # Code signing (macOS, Windows)
│   │   ├── ota/             # Over-the-air update support
│   │   └── resources/       # Resource management
│   ├── config/              # Build configuration
│   └── features.yaml        # Feature flag definitions
│
├── chromium_patches/        # BrowserOS patches applied to Chromium source
│   ├── chrome/browser/      # Browser UI and feature patches
│   ├── components/          # Component patches (e.g., os_crypt)
│   └── ...                  # Organized to mirror Chromium source tree
│
├── chromium_files/          # New files added to Chromium (not patches)
├── series_patches/          # Ordered patch series
├── resources/               # Icons, entitlements, signing resources
│   └── entitlements/        # macOS entitlements (app, helper, GPU, etc.)
│
├── tools/
│   └── bdev                 # Developer tool
│
├── CHROMIUM_VERSION          # Pinned Chromium version (MAJOR.MINOR.BUILD.PATCH)
├── BASE_COMMIT              # Base Chromium commit hash
├── pyproject.toml           # Python project config
└── requirements.txt         # Python dependencies

Build System

The browseros CLI manages the full build lifecycle:

# Install the build system
pip install -e .

# Or use uv
uv pip install -e .

Key commands:

browseros setup          # Fetch and prepare Chromium source
browseros apply          # Apply all patches to Chromium source
browseros build          # Build BrowserOS binary
browseros package        # Package into distributable (DMG, installer, AppImage)
browseros sign           # Code sign the binary (macOS/Windows)

Patch System

BrowserOS applies patches on top of vanilla Chromium. Patches are organized in two directories:

  • chromium_patches/ — Individual file patches, organized to mirror the Chromium source tree. Each file here replaces or modifies the corresponding file in Chromium.
  • series_patches/ — Ordered patch series applied sequentially.

Adding a New Patch

  1. Make your changes in the Chromium source tree
  2. Use browseros extract to pull changes back into patch format
  3. Place the patch in the appropriate directory mirroring Chromium's structure
  4. Test with a full browseros apply && browseros build cycle

Chromium Version Pinning

The exact Chromium version is pinned in CHROMIUM_VERSION:

MAJOR=146
MINOR=0
BUILD=7680
PATCH=31

To update the base Chromium version, update this file and BASE_COMMIT, then resolve any patch conflicts.

Signing (macOS)

macOS builds require code signing for Keychain access, Gatekeeper, and notarization:

  • Entitlements are in resources/entitlements/ (app, helper, GPU, renderer, etc.)
  • Designated requirements pin to Team ID for Keychain persistence across updates
  • The signing module is at build/modules/sign/macos.py

Feature Flags

Feature flags are defined in features.yaml and control which BrowserOS-specific features are compiled into the build. The feature module (build/modules/feature/) manages flag resolution at build time.