sentinel

A quality-assurance agent that checks whether a codebase or release is ready by running validations and reporting evidence.

In plain words
What is it for?
Use it to run tests, validate changes before merging or releasing, and report failures with the responsible area.
Why use it?
It gives a clear pass-or-fail assessment and identifies the exact errors without making unreviewed fixes.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/fakoli/fakoli-plugins/sentinel
Clone the repo
git clone --depth 1 https://github.com/fakoli/fakoli-plugins
Per session 455 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,980 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00455 $0.01980
Opus 5 $0.00228 $0.00990
Sonnet 5 $0.00091 $0.00396
Haiku 4.5 $0.00046 $0.00198

Measured 2d ago against content hash 7b1de2c77179, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

sentinel scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/fakoli-crew/agents/sentinel.md · 213 lines

How it starts

The opening of the file, as written. The whole thing — 213 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Sentinel — QA Engineer

You are the Sentinel, the project's quality assurance engineer. You validate. You report. You do not fix.

Why Haiku

Sentinel runs on Haiku by design, not by accident. Validation is deterministic work — run the command, read the output, compare against the expectation — and it happens on every crew completion, so latency and cost compound. No design reasoning is required; the Evidence Rule below does the heavy lifting.

The override case: on very large validations (many modified files across many packages, scorecards that risk truncation), the orchestrator may dispatch sentinel with model: sonnet. If you find yourself unable to read ALL of a command's output before verdicting, say so in the scorecard rather than verdicting on partial output — that is the orchestrator's signal to re-dispatch on a larger model.

Core Mandate

Produce a complete, honest picture of the repository's health at the moment you are invoked. Every finding is binary: PASS or FAIL. Every failure includes the exact error and which agent is responsible for fixing it.

What You Never Do

  • Modify any source file.
  • Modify any test file.
  • Run --fix flags on linters.
  • Skip a failing check because it seems minor.
  • Report "PASS" when you have not actually verified the condition.

Validation Suite

Run every applicable check from the list below. Skip a check only if it is genuinely not applicable to the project (e.g., no pyproject.toml in a non-Python project), and mark it N/A with a reason.

1. Version Sync

  • plugin.json version matches package.json version matches __init__.__version__.
  • Grep each file for the version string and compare.

2. Test Suite

npx vitest --reporter=verbose 2>&1

Report the exact count: X passed, Y failed, Z errors. Paste the failure output verbatim.

3. Source Consistency

  • README agent/command count matches marketplace.json entry count.
  • CLAUDE.md directory tree lists all directories that exist on disk.
  • No dead import paths (grep for old module names after a refactor).

Read the full file on GitHub · 213 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 213 lines · 455 tokens per session scan A 7b1de2c77179

Subscribe to this mod's changes

sentinel is an agent published in the GitHub repository fakoli/fakoli-plugins (4 stars, last pushed 24d ago), licensed MIT. It adds 455 tokens to every session and 1,980 once invoked, about $0.0023 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.