codex-app-parity

codex-app-parity is a skill for Claude Code, Codex from friuns2/codex-mobile. It costs 40 tokens per session (12,066 once invoked), scanned A, original, MIT.

A specialised guide for comparing behavior with the installed Codex desktop app. It uses the desktop app as the reference and checks results with automated browser tests and screenshots.

In plain words
What is it for?
Use it only for Codex parity work: checking features, updating related test instructions, and verifying light and dark themes or other visible behavior.
Why use it?
It helps determine whether a change matches the app's existing user-visible behavior instead of relying only on assumptions or code inspection.

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/friuns2/codex-mobile/codex-app-parity
Any agent
npx skills add friuns2/codex-mobile --skill codex-app-parity
Clone the repo
git clone --depth 1 https://github.com/friuns2/codex-mobile

Made for: Claude Code, 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 codex-app-parity

README.md
[![agentmods](https://agentmods.dev/badge/skills/friuns2/codex-mobile/codex-app-parity.svg)](https://agentmods.dev/skills/friuns2/codex-mobile/codex-app-parity)
Your own site
<a href="https://agentmods.dev/skills/friuns2/codex-mobile/codex-app-parity"><img src="https://agentmods.dev/badge/skills/friuns2/codex-mobile/codex-app-parity.svg" alt="Measured on agentmods" height="20"></a>
Per session 40 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 12,066 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00040 $0.12066
Opus 5 $0.00020 $0.06033
Sonnet 5 $0.00008 $0.02413
Haiku 4.5 $0.00004 $0.01207

Measured 4d ago against content hash b21858531417, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codex-app-parity scanned grade A with 1 finding 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 4d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

if curl -fsS "http://127.0.0.1:$port/json/list" >/tmp/codex-cdp-list.json 2>/dev/null; then
.agents/skills/codex-app-parity/SKILL.md · 789 lines

How it starts

The opening of the file, as written. The whole thing — 789 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Codex App Parity Skill

Use this skill only when the user explicitly asks for Codex parity work, names codex-app-parity, mentions Codex.app parity, or asks to compare behavior against the installed Codex desktop app. Do not auto-trigger this skill for ordinary feature work, UI changes, or user-visible behavior changes unless the user explicitly requests that parity workflow.

Objective

Ensure behavior is implemented with Codex.app as the source of truth, then verified with headless Playwright and screenshots.

Project Instructions

Repo Knowledge Maintenance

For user-visible Directory, Skills, Apps, Plugins, MCP, or Composio changes in this repo:

  • Update the relevant manual test doc under tests/<domain>/... with verification steps, including light and dark theme checks. Update tests.md only when adding, renaming, or removing a domain folder.
  • If the change creates or changes durable behavior/architecture, add or update an llm-wiki/raw/... source and corresponding llm-wiki/wiki/... concept page.
  • Keep whatToTest.md as a short pending-only checklist; remove items that were actually executed successfully.
  • Prefer assertions plus screenshots for browser validation; screenshots alone are not enough.

Codex.app-First Development Policy

For every new feature and every behavior/UI change, treat the installed desktop app as the source of truth:

  • App path: /Applications/Codex.app
  • Primary bundle to inspect: /Applications/Codex.app/Contents/Resources/app.asar

Do not implement first and compare later. Compare first, then implement.

How to Search for Features in Codex.app

Extraction

Extract the app bundle once (reuse if already extracted):

mkdir -p /tmp/codex-app-extracted
npx asar extract "/Applications/Codex.app/Contents/Resources/app.asar" /tmp/codex-app-extracted

Key Directories

Directory Contents
/tmp/codex-app-extracted/webview/assets/ Main frontend bundle (index-*.js) + locale files
/tmp/codex-app-extracted/.vite/build/ Electron main process (main.js, main-*.js, preload.js, worker.js)
/tmp/codex-app-extracted/package.json App metadata, version, entry point

Read the full file on GitHub · 789 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 4d ago First seen · 789 lines · 40 tokens per session scan A b21858531417

Subscribe to this mod's changes

codex-app-parity is a skill published in the GitHub repository friuns2/codex-mobile (892 stars, last pushed 3mo ago), licensed MIT. It adds 40 tokens to every session and 12,066 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.