Watchdog test fixture, not a mod to install. live probe: the model the engine runs for an agent registered with one alias

A second model reviews each step that Claude Code takes and sends it short notes while it works: nit, concern or blocker.

Claude Code 2.1.290 or later. Watchdog is a mod: a plugin whose code Claude Code runs inside your session. The npm stable channel (2.1.285 on 2026-10-06) has no mods. Below 2.1.290 the plugin shows unsupported. Desktop support starts when Claude.app bundles Claude Code 2.1.290 or later.
Check claude --version first. If it is below 2.1.290, move to the npm latest channel: npm install -g @anthropic-ai/claude-code@latest.
/plugin marketplace add matteoantoci/claude-plugins
/plugin install watchdog@matteoantoci-plugins
Then run /watchdog on (reviews are off until you do) and ask Claude for a small change. The note shows as a watchdog: [concern] … line in the transcript and as a card, one line with its first sentence above the prompt box. Click the card's ▸, or press ctrl+x tab and then its letter (a, b, c), to read the whole note with its watchdog, age and state; Esc gives the focus back to the prompt. Run /watchdog status to see each watchdog's reviews, notes, tokens and cost. A card names its watchdog when you run two or more.
At its right end a card shows only what needs a look: the subagent type for a note on a subagent; the state while the note has not reached Claude yet, nudge pending (the plugin starts a turn so that Claude reads it), held or aside (Claude reads it with your next prompt); nothing once it is steered (Claude reads it after its next tool result) or nudged. When Claude edited files after the review read its update, the card says outdated? N edits (the open card says may be outdated: N edits since), and Claude reads the same mark with the note. The next review of the same watchdog sees the edits and the note; when the note no longer holds, it retracts it: the card goes, and a note that waits never reaches Claude. A blocker that may be outdated and came after Claude's reply waits as held for that review before it nudges, so Claude does not go after a bug it already fixed.
plugins/watchdog/hooks/.WATCHDOG.json and WATCHDOG.md files, the session's memory files (such as CLAUDE.md), each update of the agent you work with and, when CLAUDE_WATCHDOG is set in a claude -p run, your project and local settings./watchdog on also sends one 1-token request for each model, to check that it exists. Apart from these model requests through Claude Code, the mod makes no network calls: its code never calls $.http.fetch or fetch.<config>/watchdog/dumps/ (<config> is $CLAUDE_CONFIG_DIR or ~/.claude). It keeps its notes and review state in Claude Code's session state and plugin store. In the terminal, /watchdog dump also copies the dump text to the clipboard.Read, Grep and Glob. A project WATCHDOG.json can grant no more; only <config>/WATCHDOG.json can grant other tools and mcp__* tools. Bash, Edit, Write, NotebookEdit, Agent, SendMessage, AskUserQuestion and ToolSearch are always refused. A reviewer never asks you for a permission.Agent call of a watchdog:* type) when Claude Code would ask, so no dialog or Auto-mode classifier sees it. A permission rule that denies Agent still wins.WATCHDOG.json or WATCHDOG.md sets the number of reviewers, their model, effort and instructions. In a repo you did not write, read these files before /watchdog on. Once on, /watchdog status lists each watchdog with its model, effort and file.opus with medium effort by default (in the demo: 3 reviews, 37.2k tokens, $0.07). The built-in "You should know" mod, when on, runs its own side agent too; turn it off in /plugin to pay for one only./watchdog off stops reviews for this session. /plugin uninstall watchdog@matteoantoci-plugins removes the plugin./plugin (Installed, Watchdog, Configure options) or /config: onByDefault (default false) turns reviews on in each new interactive session. immuneTurns (0 to 5, default 3) is the number of turns after a nudge before the next nudge for a concern; a nudge is a turn that the plugin starts so that Claude reads a note that came after its reply./watchdog status shows both counts, for example nudge 1/1 · blocker 0/2./watchdog or /watchdog status: each watchdog's state, reviews, notes, tokens and cost, and the session totals. For a state such as halted, see docs/failures.md./watchdog on and /watchdog off: turn reviews on or off for this session./watchdog dump and /watchdog dump raw: write the review log to a file (raw adds the review prompts).A WATCHDOG.json in your project or in ~/.claude sets the watchdogs. The load order, every key and the tool grants are in docs/configuration.md. This file adds a second reviewer to the default one:
{ "watchdogs": [{ "name": "default" }, { "name": "security", "model": "sonnet", "effort": "high" }] }
claude -p needs CLAUDE_WATCHDOG=on and has no nudge and no cards: see docs/headless.md.plugins/watchdog/hooks/prices.ts); a model not in it shows $?.npm install sets up the tools and the pre-commit hook. npm run check runs the 6 checks of pre-commit and CI: rules, fmt:check, lint, typecheck, validate and test. See docs/plugin-dev.md. Before a release and before a bump of the pinned Claude Code version, run the live probe by hand, on a real model and login: scripts/live-probe/README.md.
Apache-2.0
hooks/model.mjs 65 lines1// §16.5 model compare (§12.2): one agent of this probe mod, registered with the model __MODEL__ and spawned once at
2// the first main-loop turn end. It shows the model the engine runs for that alias (spawn result, `turn.step`,
3// `usage.model`) apart from the watchdog plugin, whose preflight `$.model.complete` can refuse the alias before any
4// spawn (§5.2). The observer logs the spawn, the steps and the end; this file logs the register and the spawn
5// result to __LOG__/rf-model.json. A hooks module cannot import node:fs (§16.3).
6const FILE = '__LOG__/rf-model.json';
7const PLUGIN = 'rfmodel';
8const state = { model: '__MODEL__', register: null, spawn: null };
9let writing = Promise.resolve();
10
11const errorOf = (error) => String(error?.message ?? error).slice(0, 800);
12
13const write = ($) => {
14 writing = writing.then(() => $.fs.write(FILE, `${JSON.stringify(state)}\n`)).catch(() => undefined);
15 return writing;
16};
17
18export const register = (on) => {
19 // §16.4 #6: a register in `session.start` resolves; the agent takes no tool and one turn.
20 on('session.start', async ($, e, next) => {
21 state.register = await $.agent
22 .register({
23 name: 'probe',
24 description: 'Model probe agent. Only the probe spawns it; never delegate to it.',
25 prompt: 'Reply with the single word OK. Do not call any tool.',
26 tools: [],
27 model: state.model,
28 effort: 'low',
29 maxTurns: 1,
30 omitClaudeMd: true,
31 background: true,
32 })
33 .then(
34 (value) => ({ value }),
35 (error) => ({ error: errorOf(error) })
36 );
37 await write($);
38 return next(e);
39 });
40
41 on('agent.offer', async ($, e, next) =>
42 String(e.agent ?? '').startsWith(`${PLUGIN}:`) ? { isOffered: false } : next(e)
43 );
44
45 // §7.2: the main `turn.complete` is a spawn site; the spawn is awaited in the live hook.
46 on('turn.complete', async ($, e, next) => {
47 const result = await next(e);
48 if (!e.agentId && state.spawn === null && state.register?.value !== undefined) {
49 state.spawn = 'pending';
50 state.spawn = await $.agent
51 .spawn({
52 subagentType: `${PLUGIN}:probe`,
53 description: 'rf model probe',
54 prompt: 'Reply with the single word OK. Do not call any tool.',
55 })
56 .then(
57 (value) => ({ value }),
58 (error) => ({ error: errorOf(error) })
59 );
60 await write($);
61 }
62 return result;
63 });
64};
65