🧐 Critic Guy

A pi extension that trusts the model. Type critic in any pi session and get a second opinion — from an independent, read-only reviewer you spawn with a single word.

No extra tools. No agent files. No configuration. Just say critic.

critic
critic review the auth code
critic using claude check for race conditions
critic model=deepseek-v4-flash review the error handling

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Why it's different — built the pi way

pi's core bet is simple: the model is capable — give it good context and good tools, then get out of the way. Critic Guy is built on exactly that bet.

It does not wrap reviewing in a rigid tool with fixed modes and schemas. It teaches the model a capability and hands over the judgment:

• What to review? The model picks the most valuable target from your conversation — you don't have to spell it out.
• One critic or several in parallel? The model decides, splitting large scope into focused reviewers however it sees fit.

The only thing Critic Guy locks down is the boundary — and it locks it down with mechanism, not by asking the model nicely:

• The critic spawns as a fresh pi -p session with read-only tools (read, grep, find, ls) — it physically cannot edit files, write files, or run shell commands.
• --offline -ne means the child never hangs on startup network calls and never re-loads this extension (so no runaway nesting).
• Its persona refuses to read credentials, secrets, or dotfiles.

Freedom in the middle, hard rails at the edge. Judgment goes to the model; safety is enforced in code.

That's the whole philosophy — and it's why Critic Guy stays a tiny prompt injection instead of a 1000-line tool. It's the most pi-native way to get a critic.

Highlights

• 🪶 Zero dependencies, zero config — no companion extension, no reviewer.md, nothing to install beyond this package.
• 🔒 Safe by construction — the reviewer is read-only and isolated; the boundary is enforced by --tools, not by trust.
• 🧠 Model-driven — you decide that you want a review; the model decides what and how.
• 💸 Zero overhead when idle — instructions are injected only on turns where you actually type critic. Silent the rest of the time.
• 🎯 Model-aware — resolves the reviewer model from your current session, or one you name with using <name> / model=<id>.

Install

# From npm
pi add npm:@nukcole-xinluo9510/pi-critic-guy

# Or from a local checkout during development
pi add /path/to/pi-critic-guy

That's it. No other setup.

Usage

In any pi session, just mention critic:

You type	What happens
critic	Model picks the most valuable thing from the conversation and reviews it
critic review the auth code	Targeted review of what you point at
critic using claude	Spawn the critic on a model matching "claude"
critic model=deepseek-v4-flash	Spawn the critic on an exact model id

Word-boundary matching means critical, criticism, etc. will not trigger it — only a standalone critic.

How it works

Critic Guy hooks before_agent_start. On any turn where you mention critic:

1. It resolves the reviewer model (your current model, the registry, or one you named).
2. It appends a short "Capability: Critic Guy" section to the system prompt — the capability, the resolved model id, and one spawn command with the hard-boundary flags.
3. The model spawns one or more critics:

   pi -p --offline -ne --no-session -nc --model "<resolved>" \
     --tools read,grep,find,ls \
     --append-system-prompt "<reviewer persona>" \
     "Task: review <files> ..."
   

4. Each critic reads the named files in its own isolated context and returns a critique, which the model relays to you.

If the system prompt is already very large, Critic Guy skips injection that turn and says so — it never silently no-ops.

Requirements

• pi 0.79+

(Yes, that's the whole list.)

Development

npm run check   # tsc --noEmit
npm test        # node --test (matchModel + parseModelQuery)

License

MIT