feature-dev

feature-dev is a command for coding agents from mturac/everything-openai-codex. It costs 11 tokens per session (253 once invoked), scanned A, a copy of feature-dev, MIT.

A guided workflow for building a software feature, from understanding the request and existing code to designing, implementing, reviewing, and testing the change.

In plain words
What is it for?
Use it to explore a project, agree on an implementation design, build the feature, review the result, and document follow-up work.
Why use it?
It helps prevent changes that conflict with the current codebase or miss important requirements and edge cases.

Command

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 commands/mturac/everything-openai-codex/feature-dev
Clone the repo
git clone --depth 1 https://github.com/mturac/everything-openai-codex

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 feature-dev

README.md
[![agentmods](https://agentmods.dev/badge/commands/mturac/everything-openai-codex/feature-dev.svg)](https://agentmods.dev/commands/mturac/everything-openai-codex/feature-dev)
Your own site
<a href="https://agentmods.dev/commands/mturac/everything-openai-codex/feature-dev"><img src="https://agentmods.dev/badge/commands/mturac/everything-openai-codex/feature-dev.svg" alt="Measured on agentmods" height="20"></a>
Per session 11 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 253 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00011 $0.00253
Opus 5 $0.00005 $0.00127
Sonnet 5 $0.00002 $0.00051
Haiku 4.5 $0.00001 $0.00025

Measured yesterday against content hash b446c316f680, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

feature-dev 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.

Origin

This is a copy

100% identical to feature-dev — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

commands/feature-dev.md · 50 lines

What it actually says

A structured feature-development workflow that emphasizes understanding existing code before writing new code.

Phases

1. Discovery

  • read the feature request carefully
  • identify requirements, constraints, and acceptance criteria
  • ask clarifying questions if the request is ambiguous

2. Codebase Exploration

  • use code-explorer to analyze the relevant existing code
  • trace execution paths and architecture layers
  • understand integration points and conventions

3. Clarifying Questions

  • present findings from exploration
  • ask targeted design and edge-case questions
  • wait for user response before proceeding

4. Architecture Design

  • use code-architect to design the feature
  • provide the implementation blueprint
  • wait for approval before implementing

5. Implementation

  • implement the feature following the approved design
  • prefer TDD where appropriate
  • keep commits small and focused

6. Quality Review

  • use code-reviewer to review the implementation
  • address critical and important issues
  • verify test coverage

7. Summary

  • summarize what was built
  • list follow-up items or limitations
  • provide testing instructions
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 · 50 lines · 11 tokens per session scan A b446c316f680

Subscribe to this mod's changes

feature-dev is a command published in the GitHub repository mturac/everything-openai-codex (89 stars, last pushed 11d ago), licensed MIT. It adds 11 tokens to every session and 253 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to feature-dev, differing in 0 lines, and is treated as a copy.