code-investigate

code-investigate is a skill for Claude Code from rp1-run/rp1. It costs 31 tokens per session (831 once invoked), scanned A, original, Apache-2.0.

A structured bug-investigation workflow that examines evidence, tests possible explanations, and documents likely root causes without changing the code permanently.

In plain words
What is it for?
Use it to investigate a reported issue, compare hypotheses with evidence, and produce a documented root-cause report.
Why use it?
It helps replace guesswork with a recorded analysis of what is happening and why. This is useful when a bug is difficult to reproduce or has several possible causes.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions subagents.

Part of the rp1-dev plugin — 23 skills, 36 agents shipped together

Good fit Use it to investigate a reported issue, compare hypotheses with evidence, and produce a documented root-cause report.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/rp1-run/rp1/code-investigate
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 rp1-run/rp1 --skill code-investigate
Clone the repo
git clone --depth 1 https://github.com/rp1-run/rp1

Made for: Claude Code.

Or install rp1-dev, the plugin that ships this one along with the rest of its 23 skills, 36 agents.

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 code-investigate

README.md
[![agentmods](https://agentmods.dev/badge/skills/rp1-run/rp1/code-investigate/github.svg)](https://agentmods.dev/skills/rp1-run/rp1/code-investigate)
Your own site
<a href="https://agentmods.dev/skills/rp1-run/rp1/code-investigate"><img src="https://agentmods.dev/badge/skills/rp1-run/rp1/code-investigate/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 code-investigate

Your own site · 80×15
<a href="https://agentmods.dev/skills/rp1-run/rp1/code-investigate"><img src="https://agentmods.dev/badge/skills/rp1-run/rp1/code-investigate.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 831 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 $0.00031 $0.00831
Opus 5 $0.00015 $0.00415
Sonnet 5 $0.00006 $0.00166
Haiku 4.5 $0.00003 $0.00083

Measured yesterday against content hash d0c90d07f08d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

code-investigate 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.

plugins/dev/skills/code-investigate/SKILL.md · 108 lines

How it starts

The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Root Cause Investigator

This command invokes the bug-investigator sub-agent for systematic issue analysis of the provided problem statement.

Before invoking the sub-agent or registering artifacts, derive EFFECTIVE_ISSUE_ID:

  • If ISSUE_ID is non-empty, use it unchanged.
  • Otherwise derive a deterministic lowercase kebab-case slug from PROBLEM_STATEMENT.
  • Collapse repeated separators, trim leading/trailing -, and if the slug would be empty use investigation.

Use EFFECTIVE_ISSUE_ID consistently for workspace paths, report paths, and agent inputs.

First emit: Generate RUN_ID as a UUID. Derive RUN_NAME from the problem statement: a brief summary (max 60 chars) prefixed with "Investigate: ".

On session start, emit the status change:

rp1 agent-tools emit \
  --workflow code-investigate \
  --type status_change \
  --run-id {RUN_ID} \
  --name "Investigate: {brief summary}" \
  --step investigating \
  --data '{"status": "running"}'

STATE-MACHINE

stateDiagram-v2
    [*] --> investigating
    investigating --> [*] : done

Invoke the bug-investigator agent with the freeform problem statement and derived issue id:

{% dispatch_agent "rp1-dev:bug-investigator" %} PROBLEM_STATEMENT={PROBLEM_STATEMENT}, ISSUE_ID={EFFECTIVE_ISSUE_ID}, KB_ROOT={kbRoot}, WORK_ROOT={workRoot} {% enddispatch_agent %}

The agent will:

  • Analyze problem statement and gather context
  • Form and test hypotheses systematically
  • Add temporary debugging (tracked and reverted)
  • Trace code execution paths
  • Identify root cause with evidence
  • Generate comprehensive investigation report
  • Propose solutions with effort estimates
  • Report back with findings

Emit btw_update events for key findings during the investigation:

rp1 agent-tools emit \
  --workflow code-investigate \
  --type btw_update \
  --run-id {RUN_ID} \
  --data '{"message": "{finding summary}"}'

After the agent writes the investigation report, register it as an artifact:

rp1 agent-tools emit \
  --workflow code-investigate \
  --type artifact_registered \
  --run-id {RUN_ID} \
  --step investigating \
  --data '{"path": "issues/{EFFECTIVE_ISSUE_ID}/investigation_report.md", "storageRoot": "work_dir", "format": "markdown"}'

Read the full file on GitHub · 108 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 · 108 lines · 31 tokens per session scan A d0c90d07f08d

Subscribe to this mod's changes

code-investigate is a skill published in the GitHub repository rp1-run/rp1 (38 stars, last pushed yesterday), licensed Apache-2.0. It adds 31 tokens to every session and 831 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 2026-09-07.

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