developer-detective

A code-investigation workflow that uses the program's structure to trace callers, callees, dependencies, and data flow. Callers are the code that uses something; callees are the functions it uses.

In plain words
What is it for?
Finding where a function is defined and used, tracing execution paths, understanding dependencies, and assessing the impact of code changes.
Why use it?
It helps explain how an unfamiliar implementation works without manually searching through every file. The results also show which parts may be affected by a change.

Skill for Claude CodeCodex

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 skills/madappgang/claude-code/developer-detective
Any agent
npx skills add MadAppGang/claude-code --skill developer-detective
Clone the repo
git clone --depth 1 https://github.com/MadAppGang/claude-code

Made for: Claude Code, Codex.

Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,023 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 $0.04023
Opus 5 $0.00028 $0.02011
Sonnet 5 $0.00011 $0.00805
Haiku 4.5 $0.00006 $0.00402

Measured 3d ago against content hash 4be0f53cab35, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

developer-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 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.

plugins/code-analysis/skills/developer-detective/SKILL.md · 496 lines

How it starts

The opening of the file, as written. The whole thing — 496 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Developer Detective Skill

This skill uses claudemem's callers/callees analysis for implementation investigation.

Why Claudemem Works Better for Development

Task claudemem Native Tools
Find usages callers shows all call sites Grep (text match)
Trace dependencies callees shows called functions Manual reading
Understand context context gives full picture Multiple reads
Impact analysis Caller chain reveals risk Unknown

Primary commands:

  • claudemem --agent callers <name> - What calls this code
  • claudemem --agent callees <name> - What this code calls
  • claudemem --agent context <name> - Full understanding

Developer Detective Skill

Version: 3.3.0 Role: Software Developer Purpose: Implementation investigation using AST callers/callees and impact analysis

Role Context

You are investigating this codebase as a Software Developer. Your focus is on:

  • Implementation details - How code actually works
  • Data flow - How data moves through the system (via callees)
  • Usage patterns - How code is used (via callers)
  • Dependencies - What a function needs to work
  • Impact analysis - What breaks if you change something

Why callers/callees is Perfect for Development

The callers and callees commands show you:

  • callers = Every place that calls this code (impact of changes)
  • callees = Every function this code calls (its dependencies)
  • Exact file:line = Precise locations for reading/editing
  • Call kinds = call, import, extends, implements

Developer-Focused Commands (v0.3.0)

Find Implementation

# Find where a function is defined
claudemem --agent symbol processPayment
# Get full context with callers and callees
claudemem --agent context processPayment```

### Trace Data Flow

```bash
# What does this function call? (data flows OUT)
claudemem --agent callees processPayment
# Follow the chain
claudemem --agent callees validateCardclaudemem --agent callees chargeStripe```

Read the full file on GitHub · 496 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. 3d ago First seen · 496 lines · 56 tokens per session scan A 4be0f53cab35

Subscribe to this mod's changes

developer-detective is a skill published in the GitHub repository MadAppGang/claude-code (279 stars, last pushed 5mo ago), licensed MIT. It adds 56 tokens to every session and 4,023 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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