Borrowing it
Nothing to install: this file belongs to richardthe3rd/cambridge-beer-festival-app. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/richardthe3rd/cambridge-beer-festival-app/main/.claude/skills/debugging-playbook/SKILL.mdgit clone --depth 1 https://github.com/richardthe3rd/cambridge-beer-festival-appWrote 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/skills/richardthe3rd/cambridge-beer-festival-app/debugging-playbook)<a href="https://agentmods.dev/skills/richardthe3rd/cambridge-beer-festival-app/debugging-playbook"><img src="https://agentmods.dev/badge/skills/richardthe3rd/cambridge-beer-festival-app/debugging-playbook/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/skills/richardthe3rd/cambridge-beer-festival-app/debugging-playbook"><img src="https://agentmods.dev/badge/skills/richardthe3rd/cambridge-beer-festival-app/debugging-playbook.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 | $0.00188 | $0.05501 |
| Opus 5 | $0.00094 | $0.02750 |
| Sonnet 5 | $0.00038 | $0.01100 |
| Haiku 4.5 | $0.00019 | $0.00550 |
Grade A, and why
debugging-playbook 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 12d 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.
| One drink category (e.g. cider) silently empty while others load | Per-type 404 soft-omission: a type returning HTTP 404 lands in NEITHER `drinksByType` NOR `failedTypes` — deliberate, so a transient mid-deploy 404 pre How it starts
The opening of the file, as written. The whole thing — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Debugging Playbook
Symptom-first triage for this codebase. Every row below comes from a real incident
(issue/PR cited); code locations verified against the working tree on 2026-07-02.
Find your symptom, run the discriminating experiment, apply the fix-pattern. If
your symptom isn't here, check skill failure-archaeology before deep-diving —
most battles in this repo have already been fought once.
How to debug here (method)
- Reproduce with the cheapest signal. Prefer a unit/widget test over the dev
server; prefer the dev server over a release build. Domain controllers
(
lib/domain/controllers/) are pure and synchronous — most state bugs reproduce in a plain Dart test. - Run tests/analyze ONCE, then grep the log.
./bin/mise run testand./bin/mise run analyzeprintTEST_LOG=/ANALYZE_LOG=paths (temp files) at the start of the run. Grep that file for different things instead of re-running the suite. See skilldiagnostics-and-toolingfor the full workflow, coverage inspection, and the source-map crash-decode scripts. - Isolate with a discriminating experiment (third column below): one cheap observation that splits the hypothesis space in half. Predict the result before running it.
- Check history before deep-diving. Skill
failure-archaeologychronicles every major investigation, rejected fix, and revert. Re-proposing a rejected fix (see Traps below) wastes a review cycle at best. - Fix through change control. Every behaviour change goes through
./bin/mise run check, a conventional commit, and PR + CI. See skillchange-control. CI is ground truth: if analyzer and tests pass, a "this won't compile" review comment is wrong.
Doc-drift warning: AGENTS.md still lists
FavoritesService/RatingsService/TastingLogServiceas separate services. They no longer exist — personal state was unified intoUserDataStore(lib/services/user_data_store.dart, #391/#395).lib/services/storage_service.dartnow contains onlyFestivalStorageService. Trust the code.
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.
- 12d ago First seen · 158 lines · 188 tokens per session scan A 471eb796ef70
debugging-playbook is a skill published in the GitHub repository richardthe3rd/cambridge-beer-festival-app (2 stars, last pushed yesterday), licensed MIT. It adds 188 tokens to every session and 5,501 once invoked, about $0.0009 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 2026-08-31.
Other skills, from other repositories
debug-optimize-lcp
Guides debugging and optimizing Largest Contentful Paint (LCP) using Chrome DevTools MCP tools. Use this skill whenever the user asks about LCP performance, slow page loads, Core Web Vitals optimization, or wants to understand why their page's main content takes too long to appear. Also use when the user mentions…
systematic-debugging
Use when debugging a failing test, build error, or runtime issue that isn't immediately obvious. Guides a 4-phase root cause analysis instead of random fix attempts.
diagnose
Trace from a reproduced symptom to the source code that causes it. Pin the specific file and approximate line, rate confidence in the cause and clarity of the fix independently, and always propose a concrete fix.
repro-admin
Reproduce an EmDash admin UI bug. Attach a container, start the demo dev server, drive the admin with agent-browser using the dev-bypass session, and capture the reproduction as screenshots plus a replayable transcript.
log-error-digest
Analyze log files to troubleshoot errors, identify peak error periods, and produce error clustering, frequency statistics, and time distribution reports. Supports JSON, syslog, and Nginx formats with automatic detection. Use when a user uploads a .log file and asks to analyze errors, find patterns, debug issues, or…
byted-util-volcengine-detect-retry
An orchestration workflow for Volcengine Cloud Detect, a service that checks websites or network endpoints from test locations.