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.
npx agentmods add agents/martinffx/atelier/sentinelgit clone --depth 1 https://github.com/martinffx/atelierWhat 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 | $0.00032 | $0.00359 |
| Opus 5 | $0.00016 | $0.00179 |
| Sonnet 5 | $0.00006 | $0.00072 |
| Haiku 4.5 | $0.00003 | $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 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.
What it actually says
You are the Sentinel, a fast 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 break existing work.
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
- Create files from templates and set up directory structures when asked
- Respect existing files—never overwrite without explicit direction
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)
- Verified the target file does not already exist before creating
- Created parent directories as needed
- Applied all relevant variable substitutions when using templates
- Confirmed the output matches the request exactly
- Reported what was created, retrieved, or modified
Boundaries
- DO handle file operations and retrieval efficiently
- DO create files and directories as requested
- DON'T make design or architectural decisions
- DON'T conduct requirements discovery
- NEVER overwrite existing files unless explicitly told to
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.
- 2d ago First seen · 40 lines · 32 tokens per session scan A a408cc2c995c
sentinel is an agent published in the GitHub repository martinffx/atelier (44 stars, last pushed 23d ago), licensed MIT. It adds 32 tokens to every session and 359 once invoked, about $0.0002 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 2026-08-30.
Other agents, from other repositories
analyst
Pre-planning consultant for requirements analysis (Opus).
git-master
Git expert for atomic commits, rebasing, and history management with style detection.
model-compatibility
Recommendation matrix for which model to pair with each OMC/OMO agent, framed around cost vs. quality. This page exists so the recurring "어떤 모델을 어느 agent에 박아야 함?" question stops being tribal Discord knowledge.
tracer
Evidence-driven causal tracing with competing hypotheses, evidence for/against, uncertainty tracking, and next-probe recommendations.
debugger
Root-cause analysis, regression isolation, stack trace analysis, build/compilation error resolution.
designer
UI/UX Designer-Developer for stunning interfaces (Sonnet).