gsd:map-codebase

A command that maps an existing codebase by having several assistants examine different areas and write a structured overview.

In plain words
What is it for?
Use it to document the project’s current structure and behavior, refresh that overview after significant changes, or onboard someone to the codebase.
Why use it?
It helps developers understand unfamiliar code before initialization, refactoring, or other major changes.

Command for Claude Code

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/geoloeg-ist/agents-reverse-engineer/map-codebase
Clone the repo
git clone --depth 1 https://github.com/GeoloeG-IsT/agents-reverse-engineer

Made for: Claude Code.

Per session 22 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 625 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 $0.00022 $0.00625
Opus 5 $0.00011 $0.00313
Sonnet 5 $0.00004 $0.00125
Haiku 4.5 $0.00002 $0.00063

Measured 2d ago against content hash 7cb8cc0ce5c6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

gsd: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.

Origin

Copies of this mod

3 near-identical copies found in the catalogue:

.claude/commands/gsd/map-codebase.md · 72 lines

What it actually says

Each mapper agent explores a focus area and writes documents directly to .planning/codebase/. The orchestrator only receives confirmations, keeping context usage minimal.

Output: .planning/codebase/ folder with 7 structured documents about the codebase state.

<execution_context> @./.claude/get-shit-done/workflows/map-codebase.md </execution_context>

Load project state if exists: Check for .planning/STATE.md - loads context if project already initialized

This command can run:

  • Before /gsd:new-project (brownfield codebases) - creates codebase map first
  • After /gsd:new-project (greenfield codebases) - updates codebase map as code evolves
  • Anytime to refresh codebase understanding

<when_to_use> Use map-codebase for:

  • Brownfield projects before initialization (understand existing code first)
  • Refreshing codebase map after significant changes
  • Onboarding to an unfamiliar codebase
  • Before major refactoring (understand current state)
  • When STATE.md references outdated codebase info

Skip map-codebase for:

  • Greenfield projects with no code yet (nothing to map)
  • Trivial codebases (<5 files) </when_to_use>

<success_criteria>

  • .planning/codebase/ directory created
  • All 7 codebase documents written by mapper agents
  • Documents follow template structure
  • Parallel agents completed without errors
  • User knows next steps </success_criteria>
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 · 72 lines · 22 tokens per session scan A 7cb8cc0ce5c6

Subscribe to this mod's changes

gsd:map-codebase is a command published in the GitHub repository GeoloeG-IsT/agents-reverse-engineer (20 stars, last pushed 25d ago), licensed MIT. It adds 22 tokens to every session and 625 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.