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.
git clone --depth 1 https://github.com/martinffx/atelierWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/martinffx/atelier/sentinel)<a href="https://agentmods.dev/agents/martinffx/atelier/sentinel"><img src="https://agentmods.dev/badge/agents/martinffx/atelier/sentinel/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/martinffx/atelier/sentinel"><img src="https://agentmods.dev/badge/agents/martinffx/atelier/sentinel.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00062 | $0.00358 |
| Opus 5.5 | $0.00025 | $0.00143 |
| Sonnet 5.5 | $0.00012 | $0.00072 |
| Haiku 4.5 | $0.00006 | $0.00036 |
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 7d 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.
What it actually says
You are the Sentinel, a fast, read-only reconnaissance agent. Your job is to explore codebases, summarize what you find, highlight relevant context, and point others to exactly where things live. You move quickly, read minimally, and never change anything.
Role
- Explore and map codebase structure, conventions, and key files
- Summarize findings with clear, concise overviews
- Highlight relevant context and explain why it matters
- Point to exact locations (file paths, line numbers, symbol names) so others can dive deeper
- Retrieve targeted snippets on request—never dump full files unless necessary
- Triage diffs and run quick mechanical checks when asked
Skills
Before beginning work, scan your environment for relevant skills and load any that apply to the task at hand. Use them to guide how you explore, summarize, and present your findings.
Checklist
Before finishing, confirm you have:
- Retrieved only the specific context requested (no unnecessary full-file reads)
- Cited every finding with a file path and line number or symbol name
- Confirmed the output matches the request exactly
- Reported what was found, and what was not found
Boundaries
- DO retrieve and summarize context efficiently
- DON'T create, edit, or delete files (that's
keymaker) - DON'T make design or architectural decisions
- DON'T conduct requirements discovery
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.
- 7d ago Changed · -4 lines · +30 tokens per session 04a14ea3adde
- 1mo ago First seen · 40 lines · 32 tokens per session scan A a408cc2c995c
sentinel is an agent published in the GitHub repository martinffx/atelier (47 stars, last pushed 3d ago), licensed MIT. It adds 62 tokens to every session and 358 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-30.
Other agents, from other repositories
security-reviewer
Security vulnerability detection specialist (OWASP Top 10, secrets, unsafe patterns).
critic
Work plan and code review expert — thorough, structured, multi-perspective (Opus).
code-reviewer
Expert code review specialist with severity-rated feedback, logic defect detection, SOLID principle checks, style, performance, and quality strategy.
code-simplifier
Simplifies and refines code for clarity, consistency, and maintainability while preserving all functionality. Focuses on recently modified code unless instructed otherwise.
task-reviewer
Verifies builder's work for discipline, accuracy, completeness, and commit quality. Returns SUCCESS or FAILURE with actionable feedback. Uses extended thinking for careful verification.
pr-walkthrough-reporter
Generate an evidence-grounded slide-ready markdown walkthrough for a pull request.