What is plugin-creator?

A guide for creating Codex plugins with the required manifest and optional supporting files.

Use it to scaffold a new plugin, configure its manifest, add optional folders, and update a personal marketplace listing.

It helps produce a valid plugin structure and marketplace entry without missing required metadata or setup steps.

plugin-creator — Skill by zm1990s

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/zm1990s/kb-agent/plugin-creator

Any agent

npx skills add zm1990s/kb-agent --skill plugin-creator

Clone the repo

git clone --depth 1 https://github.com/zm1990s/kb-agent

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 2,422 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin 98% 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.

Model	Per session	Once invoked
Fable 5	$0.00086	$0.02422
Opus 5	$0.00043	$0.01211
Sonnet 5	$0.00017	$0.00484
Haiku 4.5	$0.00009	$0.00242

Measured 2d ago against content hash 8fd56316b2c4, 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 2d ago.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/create_basic_plugin.py, scripts/read_marketplace_name.py, scripts/update_plugin_cachebuster.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

98% 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.

backend/codex_skills/.system/plugin-creator/SKILL.md · 244 lines

How it starts

The opening of the file, as written. The whole thing — 244 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plugin Creator

Quick Start

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>

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.
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.

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 · 244 lines

Files

What ships with it

9 files 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.

2d ago First seen · 244 lines · 86 tokens per session scan A 8fd56316b2c4

Subscribe to this mod's changes

plugin-creator is a skill published in the GitHub repository zm1990s/kb-agent (5 stars, last pushed 12d ago), licensed MIT. It adds 86 tokens to every session and 2,422 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 98% identical to plugin-creator, differing in 12 lines, and is treated as a copy.

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