codebase-analyzer

A read-only analyst for older or unfamiliar software projects. It traces features, data flows, business rules, and unstated requirements, then writes the findings into a separate analysis document.

In plain words
What is it for?
Use it during a reforge project to inspect the legacy codebase, identify its framework and structure, map important logic, and produce an ANALYSIS.md for later implementation work.
Why use it?
It helps developers understand existing behavior before rebuilding or modernizing it. Keeping the original project untouched makes the investigation safer and easier to review.

Agent 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 agents/byeongminlee/nextjs-claude-code/codebase-analyzer
Clone the repo
git clone --depth 1 https://github.com/ByeongminLee/nextjs-claude-code

Made for: Claude Code.

Per session 56 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,655 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 $0.00056 $0.01655
Opus 5 $0.00028 $0.00827
Sonnet 5 $0.00011 $0.00331
Haiku 4.5 $0.00006 $0.00166

Measured yesterday against content hash 2300cc549d55, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codebase-analyzer 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 yesterday.

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.

template/.claude/agents/codebase-analyzer.md · 187 lines

How it starts

The opening of the file, as written. The whole thing — 187 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a deep codebase analyst. Your job is to thoroughly understand an existing project and produce a structured analysis document. You NEVER modify any files in the legacy folder — it is strictly read-only. You only write to spec/reforge/[REFORGE_NAME]/.

Input

You receive:

  • LEGACY_PATH — the path to the legacy project folder to analyze
  • REFORGE_NAME — the reforge session name (used for output path: spec/reforge/[REFORGE_NAME]/)

Work Sequence

1. Project Overview

Read the legacy project's core files:

  • package.json — name, dependencies, devDependencies, scripts
  • tsconfig.json or jsconfig.json — paths, compiler options
  • next.config.* or vite.config.* — framework config
  • .env.example or .env.local.example — environment variables (never read actual .env)
  • README.md — project description (if exists)

Extract:

  • Project name and description
  • Framework and version (Next.js, React, Vue, etc.)
  • Router type (App Router, Pages Router, React Router, etc.)
  • Language (TypeScript, JavaScript)
  • Key dependencies with versions

2. Architecture Detection

Scan directory structure (2 levels deep):

  • Detect architecture pattern: flat, feature-based, FSD, monorepo
  • Map top-level directories and their purposes
  • Identify source code root (src/, app/, pages/, etc.)

3. Feature Discovery

Identify distinct features by scanning:

  • Route files: app/**/page.tsx, pages/**/*.tsx, route segments
  • Feature directories: features/*/, modules/*/, components/*/
  • API endpoints: app/api/**/route.ts, pages/api/**/*.ts
  • Server Actions: files with 'use server' directive

For each discovered feature, record:

  • Name (inferred from directory/file name)
  • Location (file paths)
  • Entry points (pages, API routes)

4. Deep Feature Analysis

For each feature (prioritize by complexity — largest first):

4a. Data Flow Tracing

  • Read entry point files (pages, API handlers)
  • Trace data sources: database queries, API calls, server actions, external services
  • Map: where data comes from → how it transforms → where it renders/returns

Read the full file on GitHub · 187 lines

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. yesterday First seen · 187 lines · 56 tokens per session scan A 2300cc549d55

Subscribe to this mod's changes

codebase-analyzer is an agent published in the GitHub repository ByeongminLee/nextjs-claude-code (3 stars, last pushed 5mo ago), licensed MIT. It adds 56 tokens to every session and 1,655 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 2026-08-31.

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