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 skills/archive228/loopkit/broken-window-checknpx skills add Archive228/loopkit --skill broken-window-checkgit clone --depth 1 https://github.com/Archive228/loopkitWhat 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 | $0.00046 | $0.00830 |
| Opus 5 | $0.00023 | $0.00415 |
| Sonnet 5 | $0.00009 | $0.00166 |
| Haiku 4.5 | $0.00005 | $0.00083 |
Grade A, and why
broken-window-check scanned grade A with 1 finding 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
| HTTP endpoint | `curl` the route → check status + body | Unit test on the handler function | How it starts
The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Broken-Window Check
Across shift-notes-driven sessions (see shift-notes), agents will sometimes mark a feature complete after unit tests pass — even when the feature is end-to-end broken. The next session opens the repo, sees a green git log, and builds on top of a broken foundation. By the time anyone notices, three features are stacked on the crack.
The check: before picking new work, exercise the most recently "completed" feature end-to-end. If it fails, treat it as your only job this session.
The sequence — run in order, no skipping
- Read the last "done" entry in the shift notes / feature list (whichever the project uses).
- Drive the feature end-to-end using the actual runtime path — browser automation, HTTP request, CLI invocation. Not the unit test.
- Compare observed behavior to the spec — the
stepsfield on the feature, or the acceptance criteria in the spec. - If it works — proceed to normal work selection. Note the check in the shift notes ("verified feature N still green").
- If it fails —
git revertthe commit that claimed completion (do not force-push).- Set that feature's status back to
not-donein the feature list. - Note in shift notes: "reverted feature N, cause: ".
- Fix it. That is your entire session.
Do not pick new work on top of a broken previous feature. Ever.
What "end-to-end" means
The check must exercise the path the user actually takes. Anything less is theater.
| Feature shape | Valid check | Invalid check |
|---|---|---|
| Web UI button | Puppeteer/Playwright click → observe DOM | expect(handler).toHaveBeenCalled() |
| HTTP endpoint | curl the route → check status + body |
Unit test on the handler function |
| CLI flag | Invoke the binary with the flag → observe output | Import the parser, assert on the AST |
| Background job | Trigger it → wait → assert side effect | Assert the job function returns |
Red flags — the check is not doing its job
- You're reading tests instead of running the feature. Tests can pass while the feature is broken (wrong route, missing CORS, config mismatch). Drive the runtime.
- You add a mock to make the check pass. The mock is the bug. Remove it, watch the failure, that's the real state.
- You "fix" by editing the feature list to match reality ("oh it never supported X"). No. Revert. Re-open. Fix the code or negotiate scope in the spec, not the ledger.
- You skip the check because "it worked yesterday". Yesterday's session doesn't run today's dev server.
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 · 56 lines · 46 tokens per session scan A 8ebb02364839
broken-window-check is a skill published in the GitHub repository Archive228/loopkit (753 stars, last pushed 1mo ago), licensed MIT. It adds 46 tokens to every session and 830 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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