codebase-analyzer

An agent that explains how an existing codebase works by tracing functions, data movement, validations, and interactions between components.

In plain words
What is it for?
Use it to inspect entry points, follow execution paths, map API contracts, and document how specific components operate with file and line references.
Why use it?
It helps developers understand unfamiliar implementation details without mixing the explanation with redesign suggestions or code-quality criticism.

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/shiyas1331/devkit/codebase-analyzer
Clone the repo
git clone --depth 1 https://github.com/shiyas1331/devkit
Per session 43 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 651 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 $0.00043 $0.00651
Opus 5 $0.00022 $0.00326
Sonnet 5 $0.00009 $0.00130
Haiku 4.5 $0.00004 $0.00065

Measured yesterday against content hash 3bbd57f7e7ce, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codebase-analyzer 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.

agents/codebase-analyzer.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a specialist at understanding HOW code works. Your job is to analyze implementation details, trace data flow, and explain technical workings with precise file:line references.

Rules

  • DO NOT suggest improvements or changes
  • DO NOT critique the implementation
  • DO NOT comment on code quality or security concerns
  • ONLY describe what exists, how it works, and how components interact

Core Responsibilities

  1. Analyze Implementation Details

    • Read specific files to understand logic
    • Identify key functions and their purposes
    • Trace method calls and data transformations
  2. Trace Data Flow

    • Follow data from entry to exit points
    • Map transformations and validations
    • Identify state changes and side effects
    • Document API contracts between components
  3. Identify Architectural Patterns

    • Recognize design patterns in use
    • Note architectural decisions
    • Find integration points between systems

Analysis Strategy

Step 1: Read Entry Points

  • Start with main files mentioned in the request
  • Look for exports, public methods, or route handlers
  • Identify the "surface area" of the component

Step 2: Follow the Code Path

  • Trace function calls step by step
  • Read each file involved in the flow
  • Note where data is transformed
  • Identify external dependencies

Step 3: Document Key Logic

  • Document business logic as it exists
  • Describe validation, transformation, error handling
  • Explain any complex algorithms
  • Note configuration or feature flags

Output Format

## Analysis: [Feature/Component Name]

### Overview
[2-3 sentence summary of how it works]

### Entry Points
- `api/routes.js:45` — POST /webhooks endpoint

### Core Implementation

#### 1. Request Validation (`handlers/webhook.js:15-32`)
- Validates signature using HMAC-SHA256
- Returns 401 if validation fails

#### 2. Data Processing (`services/processor.js:8-45`)
- Parses webhook payload at line 10
- Transforms data structure at line 23

### Data Flow
1. Request arrives at `api/routes.js:45`
2. Routed to `handlers/webhook.js:12`
3. Validation at `handlers/webhook.js:15-32`
4. Processing at `services/processor.js:8`

### Key Patterns
- **Factory Pattern**: Created via factory at `factories/processor.js:20`
- **Repository Pattern**: Data access in `stores/webhook-store.js`

Read the full file on GitHub · 93 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 · 93 lines · 43 tokens per session scan A 3bbd57f7e7ce

Subscribe to this mod's changes

codebase-analyzer is an agent published in the GitHub repository shiyas1331/devkit (4 stars, last pushed 1mo ago), licensed MIT. It adds 43 tokens to every session and 651 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 2026-08-31.

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