OpenCode Browser

Browser automation plugin for OpenCode.

Control your real Chromium browser (Chrome/Brave/Arc/Edge) using your existing profile (logins, cookies, bookmarks). No DevTools Protocol, no security prompts.

demo-1.mp4

Why this architecture

This version is optimized for reliability and predictable multi-session behavior:

• No MCP -> just opencode plugin
• No WebSocket port → no port conflicts
• Chrome Native Messaging between extension and a local host process
• A local broker multiplexes multiple OpenCode plugin sessions and enforces per-tab ownership

Installation

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bunx @different-ai/opencode-browser@latest install

install-1.mp4

The installer will:

1. Copy the extension to ~/.opencode-browser/extension/
2. Walk you through loading + pinning it in chrome://extensions
3. Ask for the extension ID and install a Native Messaging Host manifest
4. Update your opencode.json or opencode.jsonc to load the plugin

Configure OpenCode

Note: if you run the installer you'll be prompted to include this automatically. If you said "yes", you can skip this part.

Your opencode.json or opencode.jsonc should contain:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["@different-ai/opencode-browser"]
}

How it works

OpenCode Plugin <-> Local Broker (unix socket) <-> Native Host <-> Chrome Extension

• The extension connects to the native host.
• The plugin talks to the broker over a local unix socket.
• The broker forwards tool requests to the extension and enforces tab ownership.

Per-tab ownership

• First time a session touches a tab, the broker auto-claims it for that session.
• Other sessions attempting to use the same tab will get an error.
• Use browser_status to inspect claims if needed.

Available tools

Core primitives:

• browser_status
• browser_get_tabs
• browser_open_tab
• browser_navigate
• browser_query (modes: text, value, list, exists, page_text; optional timeoutMs/pollMs)
• browser_click
• browser_type
• browser_scroll
• browser_wait

Diagnostics:

• browser_snapshot
• browser_screenshot
• browser_version

Roadmap

• Add tab management tools (browser_set_active_tab, browser_close_tab)
• Add navigation helpers (browser_back, browser_forward, browser_reload)
• Add keyboard input tool (browser_key)
• Add download support (browser_download, browser_list_downloads)
• Add upload support (browser_set_file_input)

Troubleshooting

Extension says native host not available

• Re-run npx @different-ai/opencode-browser install
• Confirm the extension ID you pasted matches the loaded extension in chrome://extensions

Tab ownership errors

• Use browser_status to see current claims
• Close the other OpenCode session to release ownership

Uninstall

npx @different-ai/opencode-browser uninstall

Then remove the unpacked extension in chrome://extensions and remove the plugin from opencode.json or opencode.jsonc.