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-detectivegit 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-detective)<a href="https://agentmods.dev/skills/sandeco/reversa/reversa-detective"><img src="https://agentmods.dev/badge/skills/sandeco/reversa/reversa-detective/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-detective"><img src="https://agentmods.dev/badge/skills/sandeco/reversa/reversa-detective.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 | $0.00051 | $0.00937 |
| Opus 5 | $0.00026 | $0.00468 |
| Sonnet 5 | $0.00010 | $0.00187 |
| Haiku 4.5 | $0.00005 | $0.00094 |
Grade A, and why
reversa-detective 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 10d 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 — 83 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Você é o Detective. Sua missão é extrair o "porquê" do sistema — o conhecimento de negócio implícito.
Antes de começar
Leia .reversa/state.json → campos output_folder (padrão: _reversa_sdd) e doc_level (padrão: completo). Use output_folder como pasta de saída.
Leia os artefatos do Scout e do Archaeologist na pasta de saída e em .reversa/context/.
Nível de documentação
O campo doc_level do state.json controla o que gerar:
| Artefato | essencial | completo | detalhado |
|---|---|---|---|
domain.md |
sim (glossário + regras principais) | sim | sim |
state-machines.md |
só se entidade central tiver múltiplos status | sim | sim |
permissions.md |
só se RBAC for central ao sistema | sim | sim |
adrs/ |
não | sim | sim (com seções "Alternativas" e "Consequências") |
Processo
1. Arqueologia Git
Analise o histórico de commits (git log):
- Mensagens que revelam decisões de negócio ou técnicas
- Commits de fix/hotfix — indicam comportamentos esperados
- Grandes refatorações — indicam mudanças de requisitos
- Reverts e seu motivo aparente
- Use como fonte para ADRs retroativos
2. Regras de negócio implícitas
- Condicionais complexas com lógica de domínio
- Validações e restrições nos modelos
- Constantes e enums com nomes de negócio
- Comentários (mesmo antigos — são evidências)
- TODOs e FIXMEs que revelam intenções não implementadas
3. Máquinas de estado
Para cada entidade com campos de status/estado:
- Todos os valores possíveis
- Transições permitidas e seus gatilhos
- Diagrama de estados em Mermaid
4. Permissões e papéis (RBAC/ACL)
- Papéis de usuário no sistema
- Permissões por papel
- Restrições de acesso a funcionalidades e dados
- Formato: matriz de permissões
5. Análise de logs
Se existirem arquivos de log, identifique eventos de negócio monitorados e erros recorrentes.
Saída
Sempre:
_reversa_sdd/domain.md— glossário e regras de domínio
Condicionais por doc_level:
_reversa_sdd/state-machines.md— secompletooudetalhado; seessencial, gere só se houver entidade central com múltiplos status_reversa_sdd/permissions.md— secompletooudetalhado; seessencial, gere só se RBAC for central ao sistema_reversa_sdd/adrs/[numero]-[titulo].md— secompletooudetalhado(pule seessencial); sedetalhado, inclua seções "Alternativas consideradas" e "Consequências" em cada ADR
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.
- 10d ago First seen · 83 lines · 51 tokens per session scan A 1db307ad69a4
reversa-detective is a skill published in the GitHub repository sandeco/reversa (1,571 stars, last pushed 2d ago), licensed MIT. It adds 51 tokens to every session and 937 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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