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/everyinc/compound-engineering-plugin/ce-prototypenpx skills add EveryInc/compound-engineering-plugin --skill ce-prototypegit clone --depth 1 https://github.com/EveryInc/compound-engineering-pluginWhat 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 | $0.00069 | $0.01618 |
| Opus 5 | $0.00034 | $0.00809 |
| Sonnet 5 | $0.00014 | $0.00324 |
| Haiku 4.5 | $0.00007 | $0.00162 |
Grade A, and why
ce-prototype 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.
How it starts
The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Prototype
Build a throwaway prototype at the fidelity that can answer this question, before committing an approach later work will treat as given. Then apply the decisions or hand off.
Do not fake the dimension being tested. Modality, fidelity, and medium all follow from that one rule. A question about how a flow or state model behaves is settled by driving it, so a screen that only looks like the product does not answer it. A question about how a layout or a mark reads is settled by seeing it at real finish, so a thin sketch does not answer it either. The user's own perception settles the question, never your judgment of the artifact.
Result: the user decided how the product should work or feel against a prototype that did not fake what they were deciding.
Next consumer: an existing markdown Product Contract, or ce-brainstorm / ce-plan with this session as the seed.
Done: the questions that needed an artifact are decided, or the user applies and continues into brainstorm or plan.
Not: a decision a cheap sketch settles, polish, or shipping the prototype as a final product.
If there is no person to experience the prototype — LFG, mode:pipeline, or any unattended run — stop. Do not start a preview, and do not invent how it should feel. Return that this skill needs a human.
User-runnable invocation rendering. Two outputs print invocation syntax: the attended re-run in that refusal, and the next-skill recommendation when the user applies. Default to /ce-prototype, /ce-brainstorm, and /ce-plan; use $ce-prototype, $ce-brainstorm, and $ce-plan only on Codex or a host that documents dollar-prefixed skill invocation. Render only each invocation as inline code and output one form only.
Scope the question
Read references/scoping.md before you ask the user anything or touch the repo. That load is not optional. It owns how the question arrives and the scoped repo read of what the question touches — do not scan the tree. It also owns narrow vs wide, sizing, the go-ahead message, and how the remaining questions change after each decision. Do not build until the user proceeds.
What ships with it
6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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 · 58 lines · 69 tokens per session scan A 33f4f842ea7b
ce-prototype is a skill published in the GitHub repository EveryInc/compound-engineering-plugin (24,696 stars, last pushed 2d ago), licensed MIT. It adds 69 tokens to every session and 1,618 once invoked, about $0.0003 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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