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/jstxn/reinWrote 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/rules/jstxn/rein/rein-inspect)<a href="https://agentmods.dev/rules/jstxn/rein/rein-inspect"><img src="https://agentmods.dev/badge/rules/jstxn/rein/rein-inspect.svg" alt="Measured on agentmods" 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 | $0.00020 | $0.01250 |
| Opus 5 | $0.00010 | $0.00625 |
| Sonnet 5 | $0.00004 | $0.00250 |
| Haiku 4.5 | $0.00002 | $0.00125 |
Grade A, and why
rein-inspect 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 174 lines — stays where its author put it; the contents beside it link to each section on GitHub.
rein-inspect
rein-inspect is a documentation-first reconnaissance skill. Its job is to understand a codebase carefully and maintain a durable map of that understanding under .rein/codebase/.
The skill produces:
.rein/codebase/MAP.md- topical companion docs under
.rein/codebase/
It observes and records. It does not recommend fixes.
When to Use
Use this skill when:
- you need a high-signal map of an unfamiliar repo or subsystem
- a project has grown beyond what one README can orient cleanly
- you want durable codebase reference docs for future agents or humans
- repeated work keeps re-discovering the same architecture or boundary facts
Do Not Use
Do not use this skill when:
- the user asked for implementation, refactoring, or repair rather than inspection
- the repo already has a maintained codebase map that only needs a tiny manual update
- you only need a quick one-turn explanation instead of persistent docs
- you are not prepared to read enough of the codebase to support the claims you write
Operating Boundaries
- Read before writing.
- Follow actual code evidence, not guessed architecture.
- Keep output rooted at
.rein/codebase/. - Preserve and update existing docs in place.
- Add a new topical doc only when the inspected codebase reveals a real uncovered area.
- Record observations and evidence-backed inferred risks.
- Do not propose fixes, refactors, or migrations.
- Do not edit application code as part of this skill unless the user explicitly asked for code changes outside the inspection pass.
Output Contract
Always maintain this docs tree:
.rein/
codebase/
MAP.md
<topic>.md
<topic>.md
MAP.md is the entrypoint. It should explain the major sections of the codebase and link to the topical docs.
Topical docs should be created from discovered domains, not a hard-coded list. Examples might include:
architecture.mdfrontend.mdbackend.mddata-flow.mdtesting.mdtooling.md
The exact set depends on the repo.
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.
- 8d ago First seen · 174 lines · 20 tokens per session scan A 7d0c5abfc452
rein-inspect is a cursor rule published in the GitHub repository jstxn/rein (12 stars, last pushed 4mo ago), licensed MIT. It adds 20 tokens to every session and 1,250 once invoked, about $0.0001 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.
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