research_codebase

A codebase research workflow that uses several helper agents to inspect different parts of a software project and combines their findings. It is intended for answering questions about how a repository is organized and works.

In plain words
What is it for?
Use it to investigate where code lives, understand how components work, find related patterns, and produce a combined answer to a codebase question.
Why use it?
It reduces the time spent searching through files and helps connect locations, implementation details, and similar examples across a large codebase.

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/adrielp/ai-engineering-harness/research_codebase
Any agent
npx skills add adrielp/ai-engineering-harness --skill research_codebase
Clone the repo
git clone --depth 1 https://github.com/adrielp/ai-engineering-harness

Made for: Claude Code, Codex.

Per session 19 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 566 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 $0.00019 $0.00566
Opus 5 $0.00010 $0.00283
Sonnet 5 $0.00004 $0.00113
Haiku 4.5 $0.00002 $0.00057

Measured 2d ago against content hash e9b0a1591f59, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

research_codebase 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 2d 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.

claude/skills/research_codebase/SKILL.md · 90 lines

How it starts

The opening of the file, as written. The whole thing — 90 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Research Codebase

You are tasked with conducting comprehensive research across the codebase to answer user questions by spawning parallel sub-agents and synthesizing their findings.

Initial Setup:

When this command is invoked, respond with:

I'm ready to research the codebase. Please provide your research question or area of interest, and I'll analyze it thoroughly by exploring relevant components and connections.

Steps to follow after receiving the research query:

  1. Read any directly mentioned files first:

    • If the user mentions specific files, read them FULLY first
    • Read these files yourself before spawning sub-tasks
  2. Analyze and decompose the research question:

    • Break down the query into composable research areas
    • Create a research plan using TodoWrite
  3. Spawn parallel sub-agent tasks:

    For codebase research:

    • Use codebase-locator to find WHERE files and components live
    • Use codebase-analyzer to understand HOW specific code works
    • Use codebase-pattern-finder for examples of similar implementations

    For thoughts directory:

    • Use thoughts-locator to discover what documents exist
    • Use thoughts-analyzer to extract key insights from documents

    For web research (only if explicitly asked):

    • Use web-search-researcher for external documentation
  4. Wait for all sub-agents to complete and synthesize findings

  5. Generate research document at thoughts/research/YYYY-MM-DD_topic.md:

---
date: [ISO date with timezone]
researcher: [Your name]
topic: "[Research Question]"
tags: [research, relevant-tags]
status: complete
---

# Research: [Topic]

## Research Question
[Original user query]

## Summary
[High-level findings]

## Detailed Findings

### [Component/Area 1]
- Finding with reference (`file.ext:line`)
- Implementation details

## Code References
- `path/to/file.py:123` - Description

## Architecture Insights
[Patterns and design decisions discovered]

## Historical Context (from thoughts/)
[Relevant insights from thought documents]

## Open Questions
[Areas needing further investigation]

Read the full file on GitHub · 90 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. 2d ago First seen · 90 lines · 19 tokens per session scan A e9b0a1591f59

Subscribe to this mod's changes

research_codebase is a skill published in the GitHub repository adrielp/ai-engineering-harness (20 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 19 tokens to every session and 566 once invoked, about $0.0001 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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