@different-ai/opencode-browser

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.

Why this architecture

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

• 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

npx @different-ai/opencode-browser install

The installer will:

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

Configure OpenCode

Your .opencode.json 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.

Tools:

• browser_claim_tab({ tabId })
• browser_release_tab({ tabId })
• browser_list_claims()

Available tools

• browser_version
• browser_status
• browser_get_tabs
• browser_navigate
• browser_click
• browser_type
• browser_screenshot
• browser_snapshot
• browser_scroll
• browser_wait
• browser_execute

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_list_claims() to see who owns a tab
• Use browser_claim_tab({ tabId, force: true }) to take over intentionally

Uninstall

npx @different-ai/opencode-browser uninstall

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