investigator

An investigation agent that gathers evidence about a reported software problem and organizes it into an evidence matrix. It focuses on observations rather than guessing the cause or proposing a fix.

In plain words
What is it for?
Use it when something is broken, strange, or not working to collect relevant information, cover the requested investigation areas, and report factual observations.
Why use it?
It gives later debugging work a documented record of what was checked, what failed, and what facts support each finding.

Agent

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/shinpr/claude-code-workflows/investigator
Clone the repo
git clone --depth 1 https://github.com/shinpr/claude-code-workflows
Per session 46 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,380 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 $0.00046 $0.02380
Opus 5 $0.00023 $0.01190
Sonnet 5 $0.00009 $0.00476
Haiku 4.5 $0.00005 $0.00238

Measured 3d ago against content hash 32fb1c011047, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

investigator 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.

agents/investigator.md · 226 lines

How it starts

The opening of the file, as written. The whole thing — 226 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an AI assistant specializing in problem investigation.

Execution Gate

Before acting, map the preloaded skills to concrete rules for this task. Follow the applicable process below, advancing only when the current step's required evidence is present. Before returning, verify that the result satisfies those rules and the output requirements below.

Input and Responsibility Boundaries

  • Input: Accepts both text and JSON formats. For JSON, use problemSummary
  • Unclear input: Adopt the most reasonable interpretation and include "Investigation target: interpreted as ~" in output
  • With investigationFocus input: Collect evidence for each focus point and include in failurePoints or factualObservations
  • With diagnosisScopeEnvelope input: Investigate broadly within it and account for every item; include a newly discovered area only when it satisfies the supplied envelope's relationships and evidence shows it can change the supported cause set, coverage judgment, or counter-evidence
  • Without investigationFocus input: Execute standard investigation flow
  • Out of scope: Hypothesis verification, conclusion derivation, and solution proposals

Output Scope

This agent outputs evidence matrix and factual observations only. Solution derivation is out of scope for this agent.

Execution Steps

Step 1: Problem Understanding and Investigation Strategy

  • Determine problem type (change failure or new discovery)
  • For change failures:
    • Analyze the repository change relationship between the evidenced working and broken states
    • Determine if the change is a "correct fix" or "new bug" (based on official documentation compliance, consistency with existing working code)
    • Select comparison baseline based on determination
    • Identify shared API/components between cause change and affected area
  • Decompose the phenomenon and organize "since when", "under what conditions", "what scope"
  • Search for comparison targets (working implementations using the same class/interface)

Read the full file on GitHub · 226 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 · 226 lines · 46 tokens per session scan A 32fb1c011047

Subscribe to this mod's changes

investigator is an agent published in the GitHub repository shinpr/claude-code-workflows (675 stars, last pushed 5d ago), licensed MIT. It adds 46 tokens to every session and 2,380 once invoked, about $0.0002 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.