patcher-browser

Patcher is an experimental browser that lets AI coding agents generate and install custom browser extensions based on natural-language prompts. Describe what you want a website or the browser itself to do; the agent writes a Patcher plugin, displays the generated code and declared permissions, and installs it after your approval. The browser preserves persistent Chromium tabs, browsing sessions, omnibox search, real popups for OAuth/payments, history, downloads, DevTools, and tab management. Plugins can add toolbar items, side panels, context-menu entries, new-tab widgets, page scripts/styles, cron schedules, and background services with per-plugin SQLite storage. Patcher uses coding agents you already have authenticated — Claude Code, Codex, Cursor, Pi, OpenCode, Grok Build, Hermes, or any ACP-compatible agent. Agent-requested plugin changes pause for your confirmation, showing declared permissions and site scopes before installation. Security model: the approval prompt is a consent and audit boundary, not a sandbox. Browser access operates on your real authenticated sessions. Plugins run in their own process but have filesystem, subprocess, and network access as you. Treat installing a plugin like running a local script with your account's privileges. Only install plugins you understand and trust. Current limitations: macOS arm64 alpha only, not notarized, no Chrome extension compatibility, missing some features (user-facing print, spellcheck, audio indicators, download progress). Linux and WSL2 support is experimental. Built as a fork of bb by Michael Yong, using MIT license. Data directories, ports, and package names are independent so both can coexist. Install the desktop browser from GitHub releases as a .dmg for macOS Apple Silicon, or build from source with Bun. Run `npx patcher-app@latest` for the agent runtime and web app on localhost:38986.