Overwatch — Claude Code Plugin

Routes Claude Code hook events directly to the Highflame Cerberus security backend for real-time evaluation (prompt-injection detection, tool-call gating, session auditing).

This is the daemon-less install path: no local process, no background service — just the plugin and an API key. If you want the local-daemon path instead, install @highflame/overwatch from npm.

Plugins

Plugin	Platform
overwatch-mac	macOS / Linux
overwatch-windows	Windows

Each plugin wires the same Claude Code hook events and forwards them to POST /v1/hooks/evaluate?format=ide on Cerberus:

• PreToolUse (matcher .*) — gate tool calls before execution
• PostToolUse (matcher .*) — audit after tool completes
• UserPromptSubmit — inspect user prompts
• SessionStart — session-level context
• Stop — agent stop signal
• Notification — Claude Code notifications (e.g. permission prompts)

Cerberus responds in Claude Code's native hook JSON format (via ?format=ide), so blocking / allow decisions are handled end-to-end.

Install

From the Claude Code CLI:

/plugin marketplace add highflame/overwatch-claude-code
/plugin install overwatch-mac        # or overwatch-windows

For local development, point the marketplace at this checkout:

/plugin marketplace add file:///absolute/path/to/overwatch-claude-code
/plugin install overwatch-mac

Configuration

Set these in your shell environment (the Claude Code process must inherit them):

Variable	Required	Default	Purpose
HIGHFLAME_API_KEY	yes	—	Your Highflame API key
HIGHFLAME_URL	no	https://cerberus.highflame.ai	Cerberus endpoint (override for self-hosted or local dev)

If HIGHFLAME_API_KEY is not set, the hook exits 0 silently (fail-open). Claude Code is never blocked by a missing key or a network failure.

Alternatives

• Local daemon — install @highflame/overwatch (npm) and use ~/.overwatch/universal-hook.sh. The daemon listens on 127.0.0.1:17580 and auto-starts.
• Manual hooks — configure ~/.claude/settings.json directly using the templates in highflame-ramparts/packages/guardian/hooks/claudecode/.

License

Apache-2.0.