OmniDev: Instructions file for Codex

AGENTS.md

OmniDev AGENTS.md is an instructions file for Codex, OpenCode from codewithdark-git/OmniDev. It costs 2,041 tokens per session, scanned A, original, MIT.

Repository instructions for contributing production-quality Python code to OmniDev, a command-line AI coding assistant.

In plain words
What is it for?
Use them when developing, reviewing, or modifying OmniDev code.
Why use it?
They set expectations for understanding the existing code, following its structure, handling errors, adding types, and keeping changes consistent.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is codewithdark-git/OmniDev's own configuration. It tells Codex and OpenCode how to work on OmniDev itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything OmniDev configures →

Reuse

Borrowing it

Nothing to install: this file belongs to codewithdark-git/OmniDev. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/codewithdark-git/OmniDev/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/codewithdark-git/OmniDev

Made for: Codex, OpenCode.

Wrote this? Show the measurements

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Per session 2,041 This file is loaded in full into every session.
When invoked 2,041 The same file — it is already loaded in full.
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 $0.02041 $0.02041
Opus 5.5 $0.00816 $0.00816
Sonnet 5.5 $0.00408 $0.00408
Haiku 4.5 $0.00204 $0.00204

Measured 1mo ago against content hash 925c3ca72578, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

OmniDev AGENTS.md 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 1mo 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.md · 229 lines

How it starts

The opening of the file, as written. The whole thing — 229 lines — stays where its author put it; the contents beside it link to each section on GitHub.

OmniDev - Agent System Prompt & Best Practices

This document contains the system prompt and best practices for AI agents contributing code to the OmniDev codebase. Follow these guidelines to ensure production-grade, maintainable, and consistent code.


System Prompt for OmniDev Code Contributors

You are an expert Python developer contributing to OmniDev, an open-source CLI-based AI coding assistant. Your role is to write production-grade code that follows best practices, maintains consistency with the existing codebase, and contributes to the project's long-term maintainability.

Your Responsibilities

When writing code for OmniDev, you must:

  1. Understand the Codebase First: Always read and understand existing code patterns, architecture, and conventions before writing new code or modifying existing code.

  2. Follow Project Structure: Respect the established module organization and place code in appropriate directories according to the project's architecture.

  3. Write Production-Quality Code: Every function, class, and module must be production-ready with proper error handling, type hints, and documentation.

  4. Maintain Consistency: Match the existing code style, naming conventions, and patterns used throughout the codebase.

  5. Think About Maintainability: Write code that future contributors can easily understand, modify, and extend.

  6. Consider Edge Cases: Handle error conditions, validate inputs, and think about boundary cases and security implications.

  7. Document Thoroughly: Provide clear docstrings, type hints, and inline comments where necessary to explain complex logic.

  8. Test Your Code: Ensure code is testable and consider how it will be tested when writing it.


Code Quality Standards

What You Must Do

Always Use Type Hints: Every function parameter and return value must have type hints. Use Optional for nullable values, List and Dict for collections, and custom types where appropriate.

Read the full file on GitHub · 229 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. 1mo ago First seen · 229 lines · 2,041 tokens per session scan A 925c3ca72578

Subscribe to this mod's changes

OmniDev AGENTS.md is an instructions file published in the GitHub repository codewithdark-git/OmniDev (9 stars, last pushed 9mo ago), licensed MIT. It adds 2,041 tokens to every session, about $0.0082 per session on Opus 5.5. 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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