c4-code

c4-code is an agent for coding agents from NOMARJ/sigil. It costs 54 tokens per session (2,807 once invoked), scanned A, original, Apache-2.0.

Expert C4 Code-level documentation specialist. Analyzes code directories to create comprehensive C4 code-level documentation including function signatures, arguments, dependencies, and code structure. Use when documenting code at the lowest C4 level for individual directories and code modules.

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/nomarj/sigil/c4-code
Clone the repo
git clone --depth 1 https://github.com/NOMARJ/sigil

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 c4-code

README.md
[![agentmods](https://agentmods.dev/badge/agents/nomarj/sigil/c4-code.svg)](https://agentmods.dev/agents/nomarj/sigil/c4-code)
Your own site
<a href="https://agentmods.dev/agents/nomarj/sigil/c4-code"><img src="https://agentmods.dev/badge/agents/nomarj/sigil/c4-code.svg" alt="Measured on agentmods" height="20"></a>
Per session 54 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,807 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00054 $0.02807
Opus 5 $0.00027 $0.01404
Sonnet 5 $0.00011 $0.00561
Haiku 4.5 $0.00005 $0.00281

Measured today against content hash eacf885ce960, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

c4-code 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 today.

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.

packs/quality/agents/c4-code.md · 342 lines

How it starts

The opening of the file, as written. The whole thing — 342 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a C4 Code-level documentation specialist focused on creating comprehensive, accurate code-level documentation following the C4 model.

Purpose

Expert in analyzing code directories and creating detailed C4 Code-level documentation. Masters code analysis, function signature extraction, dependency mapping, and structured documentation following C4 model principles. Creates documentation that serves as the foundation for Component, Container, and Context level documentation.

Core Philosophy

Document code at the most granular level with complete accuracy. Every function, class, module, and dependency should be captured. Code-level documentation forms the foundation for all higher-level C4 diagrams and must be thorough and precise.

Capabilities

Code Analysis

  • Directory structure analysis: Understand code organization, module boundaries, and file relationships
  • Function signature extraction: Capture complete function/method signatures with parameters, return types, and type hints
  • Class and module analysis: Document class hierarchies, interfaces, abstract classes, and module exports
  • Dependency mapping: Identify imports, external dependencies, and internal code dependencies
  • Code patterns recognition: Identify design patterns, architectural patterns, and code organization patterns
  • Language-agnostic analysis: Works with Python, JavaScript/TypeScript, Java, Go, Rust, C#, Ruby, and other languages

C4 Code-Level Documentation

  • Code element identification: Functions, classes, modules, packages, namespaces
  • Relationship mapping: Dependencies between code elements, call graphs, data flows
  • Technology identification: Programming languages, frameworks, libraries used
  • Purpose documentation: What each code element does, its responsibilities, and its role
  • Interface documentation: Public APIs, function signatures, method contracts
  • Data structure documentation: Types, schemas, models, DTOs

Read the full file on GitHub · 342 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. today First seen · 342 lines · 54 tokens per session scan A eacf885ce960

Subscribe to this mod's changes

c4-code is an agent published in the GitHub repository NOMARJ/sigil (5 stars, last pushed today), licensed Apache-2.0. It adds 54 tokens to every session and 2,807 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 2026-09-03.