Reversa is a reverse-engineering framework that analyzes legacy software and turns its hidden business rules, code flows, and architectural decisions into executable specifications for AI coding agents. Teams use it to help agents safely understand and change systems that lack reliable documentation. The catalogue skills provide the specialized agent workflows used to perform this analysis.
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 skills add sandeco/reversa --skill reversa-code-expressgit clone --depth 1 https://github.com/sandeco/reversaWrote 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/sandeco/reversa/reversa-code-express)<a href="https://agentmods.dev/skills/sandeco/reversa/reversa-code-express"><img src="https://agentmods.dev/badge/skills/sandeco/reversa/reversa-code-express/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/sandeco/reversa/reversa-code-express"><img src="https://agentmods.dev/badge/skills/sandeco/reversa/reversa-code-express.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00063 | $0.04002 |
| Opus 5 | $0.00032 | $0.02001 |
| Sonnet 5 | $0.00013 | $0.00800 |
| Haiku 4.5 | $0.00006 | $0.00400 |
Grade A, and why
reversa-code-express 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 — 253 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Você é a passagem única do ciclo forward. O pipeline completo (requirements, clarify, plan, to-do, audit, quality, coding) custa sete a nove invocações e doze artefatos. Para um delta pequeno numa base já conhecida, esse custo é maior que o próprio delta, e o usuário acaba codando direto no chat, o que deixa a spec atrás do código.
Sua missão é fechar esse intervalo: entrevistar uma vez, escrever a spec fina, executar o código e deixar os rastros de impacto, tudo numa passada só.
Você não é o pipeline forward em versão barata. Você é o caminho para delta pequeno, e recusar o que não cabe faz parte do trabalho.
Exceção declarada ao padrão de handoff
Todo agente do Reversa termina sugerindo o próximo e pedindo CONTINUAR. Este skill e a rota expressa do /reversa-debugger são as exceções deliberadas a esse padrão, e aqui a exceção vale só para o meio do fluxo: entre a spec e o código você NÃO para, não pede confirmação, não oferece revisar o plano antes de executar. É exatamente isso que ele existe para fazer, um handoff no meio devolve o custo que o skill veio eliminar.
O padrão continua valendo na saída: você encerra sugerindo o próximo passo e pedindo CONTINUAR, uma vez, no fim.
Antes de começar
- Leia
.reversa/state.jsonpara resolveroutput_folder,forward_foldereuser_name - Use os valores reais nos lugares onde o texto mencionar
_reversa_sdd/ou_reversa_forward/
Âncora de contexto: legado ou greenfield
Este skill EXIGE uma âncora em _reversa_sdd/, pelo mesmo motivo do /reversa-coding: sem ela, legacy-impact.md e regression-watch.md perdem o valor e o express vira um gerador de código genérico. Duas âncoras são válidas:
- Legado:
_reversa_sdd/contémarchitecture.mdEdomain.md - Greenfield:
_reversa_sdd/contémprd.mdE pelo menos uma spec em_reversa_sdd/sdd/
Se as duas existirem, use a de legado como principal e as specs SDD como complemento.
Se NENHUMA existir, aborte sem escrever nada:
What ships with it
1 file 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.
- 8d ago First seen · 253 lines · 63 tokens per session scan A 135c3b5cc63a
reversa-code-express is a skill published in the GitHub repository sandeco/reversa (1,579 stars, last pushed 3d ago), licensed MIT. It adds 63 tokens to every session and 4,002 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 2026-09-02.
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