A token-saving working mode for simple, well-understood coding tasks. Tokens are the units used to process and generate text.

Use it for quick fixes, small changes, and other straightforward operations where you prefer a brief response.

It reduces unnecessary questions and explanations when a task is routine and the desired result is clear.

How junghwaYang/oh-my-codex configures Codex

Reuse

Borrowing it

Nothing to install: this file belongs to junghwaYang/oh-my-codex. 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/junghwaYang/oh-my-codex/main/.codex/skills/eco/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/junghwaYang/oh-my-codex

Made for: 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/junghwayang/oh-my-codex/eco/github.svg)](https://agentmods.dev/skills/junghwayang/oh-my-codex/eco)

Your own site

<a href="https://agentmods.dev/skills/junghwayang/oh-my-codex/eco"><img src="https://agentmods.dev/badge/skills/junghwayang/oh-my-codex/eco/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/junghwayang/oh-my-codex/eco"><img src="https://agentmods.dev/badge/skills/junghwayang/oh-my-codex/eco.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 363 The whole file, excluding the scripts and references it only reads on demand.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00000	$0.00363
Opus 5.5	$0.00000	$0.00145
Sonnet 5.5	$0.00000	$0.00073
Haiku 4.5	$0.00000	$0.00036

Measured 2mo ago against content hash 20a9c2ab1824, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

eco 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 2mo 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.

.codex/skills/eco/SKILL.md · 68 lines

What it actually says

Eco Skill

Token-efficient mode for simple tasks.

When to Use

Simple, well-understood tasks
Quick fixes and small changes
When user values speed over explanation
Routine operations

When NOT to Use

Complex architectural decisions
When user needs to understand the changes
Debugging (need verbose output)
Learning/teaching scenarios

Principles

1. MINIMAL CONFIRMATION
   - Don't ask "shall I proceed?" for obvious tasks
   - Just do it, show the result

2. TERSE OUTPUT
   - Skip explanations unless asked
   - Show diff, not description
   - One-line summaries

3. FAST ROUTING
   - Use simplest approach
   - Avoid over-engineering
   - Skip optional validations for trivial changes

4. BATCH WHEN POSSIBLE
   - Combine related small changes
   - Single commit for related fixes

Response Format

✓ {what was done}

That's it. No preamble, no follow-up questions unless truly needed.

Examples

User: "eco: add .env to gitignore" Response:

✓ Added .env to .gitignore

User: "eco: fix the typo in line 42" Response:

✓ Fixed "recieve" → "receive" in src/utils.ts:42

Anti-patterns

❌ "I'll help you add .env to your .gitignore file. Let me first check if the file exists..."

❌ "Done! I've successfully added .env to your .gitignore. Is there anything else you'd like me to help with?"

✅ "✓ Added .env to .gitignore"

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.

2mo ago First seen · 68 lines · 0 tokens per session scan A 20a9c2ab1824

Subscribe to this mod's changes

eco is a skill published in the GitHub repository junghwaYang/oh-my-codex (5 stars, last pushed 8mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 363 tokens. 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.

Productivity

eco next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
ecojunghwaYang/oh-my-codex	Skill	5	8mo ago	MIT	A	0	Codex
orbit-notionnexu-io/open-design	Skill	106k	today	Apache-2.0	A	117	Claude Code, Codex
agentmailpaperclipai/paperclip	Skill	112k	today	MIT	A	30	Claude Code, Codex
Cortexdanielmiessler/LifeOS	Skill	20k	yesterday	MIT	A	184	Claude Code
rowboat-spacesrowboatlabs/rowboat	Skill	18k	today	Apache-2.0	A	60	Claude Code, Codex
feishuHmbown/CodeWhale	Skill	41k	6d ago	MIT	A	33	Claude Code, Codex
pinchtab-mcppinchtab/pinchtab	Skill	11k	10d ago	MIT	A	52	Claude Code, Codex

oh-my-codex: Skill for Codex