plugin-creator

A starter tool for creating Codex plugins, which package skills, tools, or other add-ons together.

In plain words
What is it for?
Use it to scaffold a plugin, set its basic metadata, and optionally add it to a personal plugin marketplace.
Why use it?
It removes the need to build the required plugin folder and manifest by hand.

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/chenrui333/codex-docs/plugin-creator
Any agent
npx skills add chenrui333/codex-docs --skill plugin-creator
Clone the repo
git clone --depth 1 https://github.com/chenrui333/codex-docs

Made for: Claude Code, Codex.

Per session 86 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,250 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 89% 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 $0.00086 $0.03250
Opus 5 $0.00043 $0.01625
Sonnet 5 $0.00017 $0.00650
Haiku 4.5 $0.00009 $0.00325

Measured yesterday against content hash cf944fb3b5db, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plugin-creator 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.

The scan reads SKILL.md. This mod also ships 5 executable files (scripts/create_basic_plugin.py, scripts/identifier_validation.py, scripts/read_marketplace_name.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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

89% identical to plugin-creator — 12 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.

dot_codex/skills/dot_system/plugin-creator/SKILL.md · 258 lines

How it starts

The opening of the file, as written. The whole thing — 258 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plugin Creator

Quick Start

  1. Run the scaffold script:
# Plugin names are normalized to lower-case hyphen-case and must be <= 64 chars.
# The generated folder and plugin.json name are always the same.
# Run from the skill root (the directory containing this `SKILL.md`).
# By default creates in `~/plugins/<plugin-name>`.
python3 scripts/create_basic_plugin.py <plugin-name>
  1. Edit <plugin-path>/.codex-plugin/plugin.json when the request gives specific metadata. The scaffold starts with valid defaults and must not contain [TODO: ...] placeholders.

  2. Generate or update the personal marketplace entry when the plugin should appear in Codex UI ordering:

# Personal marketplace entries default to `~/.agents/plugins/marketplace.json`.
python3 scripts/create_basic_plugin.py my-plugin --with-marketplace

Only specify --marketplace-name <name> when the default personal marketplace name is already taken or installed and you need to seed a different new marketplace file:

python3 scripts/create_basic_plugin.py my-plugin \
  --with-marketplace \
  --marketplace-name team-local

Only use a repo/team marketplace when the user specifically asks for that destination:

python3 scripts/create_basic_plugin.py my-plugin \
  --path <repo-root>/plugins \
  --marketplace-path <repo-root>/.agents/plugins/marketplace.json \
  --with-marketplace

When the user specifies a marketplace path, make sure that marketplace is actually installed before telling the user to reinstall from it. The default personal marketplace file at ~/.agents/plugins/marketplace.json is discovered implicitly, but other marketplace paths are not. On Windows, use the equivalent path under the user profile.

  1. Generate/adjust optional companion folders as needed:
python3 scripts/create_basic_plugin.py my-plugin \
  --path <parent-plugin-directory> \
  --marketplace-path <marketplace-json-path> \
  --with-skills --with-hooks --with-scripts --with-assets --with-mcp --with-apps --with-marketplace

Read the full file on GitHub · 258 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. yesterday First seen · 258 lines · 86 tokens per session scan A cf944fb3b5db

Subscribe to this mod's changes

plugin-creator is a skill published in the GitHub repository chenrui333/codex-docs (5 stars, last pushed yesterday), licensed MIT. It adds 86 tokens to every session and 3,250 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 89% identical to plugin-creator, differing in 12 lines, and is treated as a copy.