ultrathink-detective

ultrathink-detective is a skill for Claude Code from MadAppGang/claude-code. It costs 68 tokens per session (7,752 once invoked), scanned A, original, MIT.

A broad codebase investigation workflow that examines architecture, implementation paths, tests, and possible causes of problems from several viewpoints.

In plain words
What is it for?
Use it for comprehensive audits, architecture reviews, complex debugging, dependency tracing, and finding gaps in test coverage.
Why use it?
It brings related evidence together for difficult investigations instead of checking isolated files or symbols one at a time.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: model in frontmatter; names the AskUserQuestion tool; positional $N argument.

Part of the code-analysis plugin — 12 skills, 2 commands, 1 agent shipped together

Good fit Use it for comprehensive audits, architecture reviews, complex debugging, dependency tracing, and finding gaps in test coverage.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/madappgang/claude-code/ultrathink-detective
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 MadAppGang/claude-code --skill ultrathink-detective
Clone the repo
git clone --depth 1 https://github.com/MadAppGang/claude-code

Made for: Claude Code.

Or install code-analysis, the plugin that ships this one along with the rest of its 12 skills, 2 commands, 1 agent.

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.

agentmods badge for ultrathink-detective

README.md
[![agentmods](https://agentmods.dev/badge/skills/madappgang/claude-code/ultrathink-detective/github.svg)](https://agentmods.dev/skills/madappgang/claude-code/ultrathink-detective)
Your own site
<a href="https://agentmods.dev/skills/madappgang/claude-code/ultrathink-detective"><img src="https://agentmods.dev/badge/skills/madappgang/claude-code/ultrathink-detective/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for ultrathink-detective

Your own site · 80×15
<a href="https://agentmods.dev/skills/madappgang/claude-code/ultrathink-detective"><img src="https://agentmods.dev/badge/skills/madappgang/claude-code/ultrathink-detective.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 68 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 7,752 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 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 5.1 $0.00068 $0.07752
Opus 5 $0.00034 $0.03876
Sonnet 5 $0.00014 $0.01550
Haiku 4.5 $0.00007 $0.00775

Measured 11d ago against content hash 6837791f4c3d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

ultrathink-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 11d 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/ultrathink-detective/SKILL.md · 893 lines

How it starts

The opening of the file, as written. The whole thing — 893 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ultrathink Detective Skill

This skill uses ALL claudemem commands for comprehensive multi-perspective investigation.

Combines All Detective Perspectives

Perspective Focus Commands Used
Architect System design, layers map, symbol
Developer Implementation, flow callers, callees
Tester Coverage, gaps callers for tests
Debugger Root cause, chains context

Full command set:

  • claudemem --agent map "query" - Architecture overview
  • claudemem --agent symbol <name> - Exact locations
  • claudemem --agent callers <name> - Impact analysis
  • claudemem --agent callees <name> - Dependency tracing
  • claudemem --agent context <name> - Full call chain
  • claudemem --agent search "query" - Semantic search

Ultrathink Detective Skill

Version: 3.3.0 Role: Senior Principal Engineer / Tech Lead Model: Opus (for maximum reasoning depth) Purpose: Comprehensive multi-dimensional codebase investigation using ALL AST analysis commands with code health assessment

Role Context

You are investigating as a Senior Principal Engineer. Your analysis is:

  • Holistic - All perspectives (architecture, implementation, testing, debugging)
  • Deep - Beyond surface-level using full call chain context
  • Strategic - Long-term implications from PageRank centrality
  • Evidence-based - Every conclusion backed by AST relationships
  • Actionable - Clear recommendations with priorities

Why Ultrathink Uses ALL Commands

Command Primary Use Ultrathink Application
map Architecture overview Dimension 1: Structure discovery
symbol Exact locations Pinpoint critical code
callers Impact analysis Dimensions 2-3: Usage patterns, test coverage
callees Dependencies Dimensions 4-5: Data flow, reliability
context Full chain Bug investigation, root cause analysis
search Semantic query Dimension 6: Broad pattern discovery

Read the full file on GitHub · 893 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. 11d ago First seen · 893 lines · 68 tokens per session scan A 6837791f4c3d

Subscribe to this mod's changes

ultrathink-detective is a skill published in the GitHub repository MadAppGang/claude-code (279 stars, last pushed 5mo ago), licensed MIT. It adds 68 tokens to every session and 7,752 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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