map-codebase

A command that maps an existing repository into Memory Bank documentation: baseline files that describe how the codebase currently works. It is intended for a brownfield project, meaning an existing codebase rather than a new one.

In plain words
What is it for?
Use it when onboarding to an unfamiliar repository or creating current-state documentation before further work. The mapping records discovery evidence in a task folder and updates the Memory Bank.
Why use it?
It creates an evidence-based overview of the repository's product, architecture, specifications, runbooks, contracts, and state rules instead of relying on assumptions.

Command

Install

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.

agentmods
npx agentmods add commands/nicelight/devrails-26/map-codebase
Clone the repo
git clone --depth 1 https://github.com/nicelight/DevRails-26
Per session 19 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 835 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00019 $0.00835
Opus 5 $0.00010 $0.00417
Sonnet 5 $0.00004 $0.00167
Haiku 4.5 $0.00002 $0.00084

Measured 2d ago against content hash 737784437a1b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

map-codebase 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.

skills/_shared/references/commands/map-codebase.md · 80 lines

What it actually says

/map-codebase — Brownfield mapping

  1. Создай .tasks/TASK-MB-MAP/.
  2. Выбери минимально достаточную тактику discovery по фактическому размеру и структуре repository:
  • для малого repository или очевидного полного read set используй direct reads одним агентом;
  • для действительно широкого discovery /context-manifest или bounded delegation допустимы только когда это дешевле direct reads и текущие роль и operator contract разрешают delegation;
  • delegation не является default; delegated agent не запускает других агентов;
  • поисковые globs должны матчиться, а evidence должно покрывать применимые code, config, CI/tooling, data/state и test surfaces.

Записывай substantive mapping evidence и отчёты в .tasks/TASK-MB-MAP/ независимо от выбранной тактики.

  1. Синтезируй evidence-backed as-is current-state baseline .memory-bank/ по чеклисту:
  • product
  • architecture (C4)
  • spec-index / spec-backbone / glossary / invariants (только для регистрации существующих artifacts и явно обозначенного current-state routing; не выводи normative target или Global Backbone decision из кода)
  • runbooks
  • contracts
  • states (если lifecycle/state rules очевидны из кода, workflow или тестов)
  • testing
  • index

/map-codebase фиксирует change units/code roots, imports/calls, events/background work, writers/state paths, runtime entrypoints и proof paths только как as-is evidence, не target authority или accepted graph rows.

PRD-less rule (non-negotiable): если нет prd.md, запрещено генерировать roadmap сущности:

  • .memory-bank/epics/*
  • .memory-bank/features/*
  • .memory-bank/tasks/*.task.json task records
  • .memory-bank/tasks/index.json task links

Маппинг = as-is документация по evidence, а не планирование.

  1. Проверь качество baseline:
  • отдели facts от inferences и явно привяжи их к evidence;
  • противоречия, недоказанные выводы и неполное покрытие запиши как needs verification / unresolved evidence;
  • не заменяй существующие baseline facts догадками.
  • помечай as-is claims как current state, чтобы downstream skill не принял их за желаемую архитектуру;
  • если обновляемый artifact уже содержит accepted target, сохрани его и явно отдели от current state; не создавай и не изменяй target AD-*, normative rules или architecture decisions на основании одного as-is evidence;
  • если current отличается от accepted target, зафиксируй оба состояния и уже известный reconciliation route в существующем owning artifact. Само отличие является delta, а не authority conflict; неизвестную material route оставь unresolved для её downstream owner. Не создавай второй dependency graph или обязательный artifact для этого разделения.
  1. Заверши immediate handoff:
  • если authoritative PRD/delta уже передан вызывающим workflow, сохрани его как downstream input и не спрашивай повторно; верни invoking workflow/current PRD owner ссылки на baseline вместе с тем же переданным PRD/delta;
  • если PRD/delta не передан, заверши as-is baseline, запроси его у оператора и остановись;
  • не воспроизводи дальнюю downstream chain и не переходи к roadmap, task generation или execution из /map-codebase.
Changes

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.

  1. 2d ago First seen · 80 lines · 19 tokens per session scan A 737784437a1b

Subscribe to this mod's changes

map-codebase is a command published in the GitHub repository nicelight/DevRails-26 (22 stars, last pushed 4d ago), licensed MIT. It adds 19 tokens to every session and 835 once invoked, about $0.0001 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.