Build from Source

This guide covers prerequisites, platform-specific requirements, and build steps for compiling Browser4 from source.

Prerequisites

Tool	Minimum Version	Required For	Notes
Git	any	Clone, root discovery
JDK	17+ (21+ recommended)	Build & runtime	Eclipse Temurin recommended. JDK 21+ enables best jlink compression (zip-9).
Maven	3.9+	Java build	Included via mvnw wrapper — no separate install needed.
PowerShell 7 (pwsh)	7.0+	Runtime bundle assembly (jlink)	Required on Linux and macOS. Built-in on Windows (powershell.exe). Install: curl -fsSL https://aka.ms/install-powershell.sh | bash
JDK tools (jdeps, jlink, jpackage)	bundled with JDK 16+	Runtime bundle assembly	Included in your JDK installation — no separate install needed.
Chrome / Chromium	latest	Runtime	See auto-detection paths below. Docker images bundle Chromium via apk add chromium.
Rust	stable (edition 2021)	CLI build only	Only needed when building browser4-cli from source (not needed for the Java backend).
Node.js + pnpm	Node 24 / pnpm 10	CLI distribution	Only needed when packaging the CLI for npm publish.

Platform-specific tools for runtime bundle assembly

Platform	Additional tools
Linux	tar, wget or curl
macOS	tar
Windows	powershell.exe (built-in) — Windows PowerShell 5.1+ is sufficient

Chrome Setup

Auto-detection paths

Platform	Search paths
Windows	C:\Program Files\Google\Chrome\Application\chrome.exe, C:\Program Files (x86)\Google\Chrome\Application\chrome.exe
macOS	/Applications/Google Chrome.app/Contents/MacOS/Google Chrome, /Applications/Chromium.app/Contents/MacOS/Chromium
Linux	/opt/google/chrome/chrome, /usr/bin/google-chrome, /usr/bin/chromium-browser, PATH: google-chrome, chromium-browser, chromium

Automatic installation

If Chrome is not found, the CLI attempts automatic installation:

• Windows: via winget or PowerShell download of the standalone installer
• Debian/Ubuntu: via wget/curl + sudo dpkg -i
• RHEL/Fedora: via curl + sudo dnf install -y
• macOS: prints brew install --cask google-chrome instructions

Build Steps

1. Clone the repository

   git clone https://github.com/platonai/Browser4.git
   cd Browser4
   

2. Configure your LLM API key

   Edit application.properties and add your API key, or set environment variables. See LLM Configuration for supported providers and variable names.

3. Build the project

   ./mvnw -DskipTests
   

Building the CLI

The CLI (browser4-cli) is a Rust binary that communicates with the Browser4 backend. It requires Rust (stable, edition 2021) — see the prerequisites table above.

Running without installing (recommended for development):

# From the repo root:
cargo run --manifest-path cli/browser4-cli/Cargo.toml -- <command>

# Or from the CLI directory:
cd cli/browser4-cli
cargo run -- <command>

The backend server starts automatically on first use (no manual ./mvnw required).

Building the release binary:

cd cli/browser4-cli
cargo build --release
# Binary at: target/release/browser4-cli[.exe]

Installing globally:

cd cli/browser4-cli
cargo install --path .
# Now available as: browser4-cli <command>