What is ferrox-map-codebase?

A codebase mapping workflow that explores an unfamiliar repository and writes seven structured documents describing its current state. A brownfield project means an existing project that you are joining or changing.

Use it to create or refresh a codebase map, focus the scan on an area, or query the gathered information.

It reduces the time needed to understand how an existing codebase is organized before planning changes.

ferrox-map-codebase — Skill for Claude Code by FerroxLabs

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.

Any agent

npx skills add FerroxLabs/ferrox-factory --skill ferrox-map-codebase

Clone the repo

git clone --depth 1 https://github.com/FerroxLabs/ferrox-factory

Made for: Claude Code.

Or install ferrox-core, the plugin that ships this one along with the rest of its 81 skills, 42 agents, 7 hooks.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/ferroxlabs/ferrox-factory/ferrox-map-codebase.svg)](https://agentmods.dev/skills/ferroxlabs/ferrox-factory/ferrox-map-codebase)

Your own site

<a href="https://agentmods.dev/skills/ferroxlabs/ferrox-factory/ferrox-map-codebase"><img src="https://agentmods.dev/badge/skills/ferroxlabs/ferrox-factory/ferrox-map-codebase.svg" alt="Measured on agentmods" height="20"></a>

Per session 23 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 864 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 86% copy Near-identical to another mod 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.

Model	Per session	Once invoked
Fable 5.1	$0.00023	$0.00864
Opus 5	$0.00012	$0.00432
Sonnet 5	$0.00005	$0.00173
Haiku 4.5	$0.00002	$0.00086

Measured 3d ago against content hash b3961e859106, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

ferrox-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 3d 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

This is a copy

86% identical to gsd-map-codebase — 18 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/ferrox-map-codebase/SKILL.md · 84 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/ferrox-core/workflows/map-codebase.md </execution_context>

Parse the first token of $ARGUMENTS:

If it is --fast: strip the flag, run the scan workflow (passing remaining args including optional --focus).
If it is --query: strip the flag, run the intel workflow (passing remaining args as the subcommand).
Otherwise: pass all of $ARGUMENTS as focus area to the map-codebase workflow.

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

This command can run:

Via /ferrox-onboard for first-time brownfield setup - creates codebase map first
After /ferrox-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
Refreshing or deepening an onboarded codebase map
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.

3d ago First seen · 84 lines · 23 tokens per session scan A b3961e859106

Subscribe to this mod's changes

ferrox-map-codebase is a skill published in the GitHub repository FerroxLabs/ferrox-factory (22 stars, last pushed 1mo ago), licensed MIT. It adds 23 tokens to every session and 864 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to gsd-map-codebase, differing in 18 lines, and is treated as a copy.

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

local-ai-agents

Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…

microsoft/ai-agents-for-beginners · 200 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

next-partial-prefetching-adoption

Turn on Partial Prefetching in a Next.js app and work through the insights it surfaces. Use when the user wants to enable or adopt Partial Prefetching, flip the partialPrefetching flag, opt routes in with export const prefetch = 'partial', audit Link prefetch={true} behavior, preserve existing prefetched UI with…

vercel/next.js · 103 tokens

chronicle

Analyze Copilot session history for standup reports, usage tips, session search, and session reindexing. Use when the user asks for a standup, daily summary, usage tips, workflow recommendations, wants to search or find past sessions by keyword/file/PR, wants to reindex their session store, or asks about deleting…

microsoft/vscode · 72 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens