Claude in Chrome — Windows Fix

Claude Code plugin that fixes claude-in-chrome MCP tools on Windows — flat illustration of a browser window and a terminal window connected by a glowing data pipe with a wrench over the pipe symbolizing the patch

cli.js breaks claude-in-chrome on Windows every time it updates. This plugin patches it on every session start so Chrome tools just work.

The Problem

On Windows, every mcp__claude-in-chrome__* call fails with Browser extension is not connected — even when the extension is signed in, the native host is running, and \\.\pipe\claude-mcp-browser-bridge-<user> is healthy.

Root cause: the Chrome MCP connector factory in cli.js unconditionally prefers the cloud WebSocket bridge (wss://bridge.claudeusercontent.com) and has no fallback to the local socket pool. The cloud path fails (list_extensions returns empty for the account) and there's nothing to catch it. See anthropics/claude-code#23828 for the full diagnosis.

The Solution

A SessionStart hook that:

Locates cli.js via npm root -g
Checks whether the Windows fix marker is already present
If missing, backs up cli.js and applies a one-line patch that forces the local socket pool on Windows
Self-heals across Claude Code auto-updates — no manual re-patching after every release
Pure no-op on macOS and Linux

Every run writes a status blob to ~/.claude/cache/claude-in-chrome-patch.json so you can tell at a glance whether everything's healthy.

How It Works

The patch. In cli.js 2.1.96 the connector factory reads:

function J51(q){return q.bridgeConfig?RO8(q):q.getSocketPaths?Oy7(q):EO8(q)}

where RO8 is the cloud BridgeClient and Oy7 is the local socket pool. The plugin rewrites it to:

function J51(q){if(process.platform==="win32"&&q.getSocketPaths)return Oy7(q);return q.bridgeConfig?RO8(q):q.getSocketPaths?Oy7(q):EO8(q)}

Non-Windows behavior is unchanged.

The hook. Runs on every SessionStart. If the patch marker is already present, it's a silent no-op. If not, it takes a timestamped backup (~/.claude/backups/cli.js.<timestamp>.plugin.bak), applies the textual replacement, verifies the write, and records the result.

Heals the next session, not the current one. SessionStart hooks run after cli.js is already loaded in memory, so the plugin heals the session that follows a Claude Code update, not the one triggering it. If Chrome tools fail immediately after an update, restart Claude Code once — they'll come back.

Status Reference

cat ~/.claude/cache/claude-in-chrome-patch.json — the status field tells you what happened on the last run.

Status	Meaning
`already-patched`	Everything is fine. Steady state.
`reapplied`	Patch was missing (likely a Claude Code update), it was re-applied, `cli.js` is fixed for the next session.
`needs-manual-intervention`	Minified symbol names in `cli.js` drifted in an update. Re-derive the patch constants. See Updating.
`skipped-non-windows`	Running on macOS or Linux. Nothing to fix.
`cli-not-found`	Couldn't locate `cli.js`. Unusual install layout?
`aborted-multiple-matches`	Target string appears more than once. Aborted for safety.
`error`	Unexpected failure. See `message` field.

Installation

Via Claude Code marketplace

/plugin marketplace add https://github.com/robertmonroe/claude-in-chrome-windows-fix
/plugin install claude-in-chrome-windows-fix

Restart Claude Code so the hook fires on the next session.

Local path (for testing or development)

git clone https://github.com/robertmonroe/claude-in-chrome-windows-fix.git
claude --plugin-dir ./claude-in-chrome-windows-fix

Updating

When Claude Code ships a new cli.js bundle with reshuffled minified names, the hook will record needs-manual-intervention and Chrome tools will start failing again. To fix:

Open cli.js — path is in the status file's cliPath field.
Search for bridgeConfig?. You want a tiny factory function of the shape function XXX(q){return q.bridgeConfig?YYY(q):q.getSocketPaths?ZZZ(q):WWW(q)} where YYY is the cloud BridgeClient and ZZZ is the local socket pool.
Update the ORIGINAL, PATCHED, and PATCHED_MARKER constants at the top of hooks/claude-in-chrome-patch.js to match the new minified names.
Commit, push, bump the plugin version.

The shape of the factory (bridgeConfig ? X : getSocketPaths ? Y : Z) is stable across minifier runs even when the symbol names churn — that's what makes the textual patch viable across versions.

Rollback

Every patch takes a backup first. To roll back:

cp ~/.claude/backups/cli.js.<timestamp>.plugin.bak "$(npm root -g)/@anthropic-ai/claude-code/cli.js"