Borrowing it
Nothing to install: this file belongs to micheltlutz/dev-challenge. 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/micheltlutz/dev-challenge/main/.claude/skills/challenge-workflow/SKILL.mdgit clone --depth 1 https://github.com/micheltlutz/dev-challengeWrote 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/micheltlutz/dev-challenge/challenge-workflow)<a href="https://agentmods.dev/skills/micheltlutz/dev-challenge/challenge-workflow"><img src="https://agentmods.dev/badge/skills/micheltlutz/dev-challenge/challenge-workflow/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/micheltlutz/dev-challenge/challenge-workflow"><img src="https://agentmods.dev/badge/skills/micheltlutz/dev-challenge/challenge-workflow.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium MCP Rug Pull · line 79 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
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 | $0.00087 | $0.01276 |
| Opus 5.5 | $0.00035 | $0.00510 |
| Sonnet 5.5 | $0.00017 | $0.00255 |
| Haiku 4.5 | $0.00009 | $0.00128 |
Grade A, and why
challenge-workflow 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 2mo 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 — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Challenge workflow
The spec-driven loop this lab is built around. Follow it yourself, and walk the learner through it.
Before anything: posture
Read "First: which job are you doing?" in AGENTS.md.
Default to mentoring. The person is here to learn; the code is the medium, not the deliverable. Plan with them, review what they write, name the failing criterion and explain why — but do not hand over the implementation unless they ask for it.
They can switch you off this at any time: "just write it", "show me a
solution", --solve. When they do, switch cleanly, say you have switched, and
do a proper job. Withholding while pretending you cannot help is worse than
useless.
Scaffolding, config, build setup and boilerplate are always fine to write
outright. Nobody learns from a tsconfig.json. Save the mentoring for the
logic the challenge is actually about.
1. Read the spec
cat specs/challenges/<id>/spec.md
cat specs/challenges/<id>/acceptance.md
Never answer from readme_files/ — those are redirect stubs — or from how such
an API usually works. The briefs disagreed with the running API for a long time;
that is why this layer exists.
If it is a web or mobile challenge, also read:
specs/design/style-guide.mdspecs/design/tokens.css— import it, do not hard-code hex- the
mockups:listed in the frontmatter
Note the testids: list. It is a contract: the harness drives the UI through
those values, so an implementation that omits them cannot be verified no matter
how good it looks.
2. Clarify
Ambiguity in a spec is a bug in the spec, not something to guess past. Surface it, state the assumption you would make, and suggest opening an issue. Fixing a spec is a real contribution and the specs say so.
3. Plan
Turn the acceptance criteria into a checklist before writing code. Order it so that the criteria a failure would cascade from come first — usually authentication, then scoping, then the feature.
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.
- 2mo ago First seen · 134 lines · 87 tokens per session scan A 44f5c3de6da9
challenge-workflow is a skill published in the GitHub repository micheltlutz/dev-challenge (33 stars, last pushed 5d ago), licensed MIT. It adds 87 tokens to every session and 1,276 once invoked, about $0.0003 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.
challenge-workflow compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| challenge-workflowmicheltlutz/dev-challenge | Skill | 33 | 5d ago | MIT | A | 87 | Claude Code |
| a0-developmentagent0ai/agent-zero | Skill | 20k | yesterday | none | A | 24 | Claude Code, Codex |
| fastapialivirgo/Major-AI-Skills | Skill | 2 | yesterday | MIT | A | 52 | Claude Code |
| alembic-migrationsrobhowley/py-pit-skills | Skill | 5 | 7mo ago | MIT | A | 56 | Claude Code |
| testingpluginagentmarketplace/custom-plugin-backend | Skill | 5 | 10mo ago | none | A | 24 | Claude Code |
| build-zoom-contact-center-appanthropics/knowledge-work-plugins | Skill | 35k | 2d ago | Apache-2.0 | A | 48 | Claude Code |
| api-rate-limit-handlersickn33/agentic-awesome-skills | Skill | 49k | yesterday | MIT | A | 32 | Claude Code |