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.
npx agentmods add skills/openai/codex/plugin-creatornpx skills add openai/codex --skill plugin-creatorgit clone --depth 1 https://github.com/openai/codexWhat 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 | $0.02518 |
| Opus 5 | $0.00043 | $0.01259 |
| Sonnet 5 | $0.00017 | $0.00504 |
| Haiku 4.5 | $0.00009 | $0.00252 |
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.
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.
Copies of this mod
8 near-identical copies found in the catalogue:
- plugin-creator — 100% identical, 0 lines differ
- plugin-creator — 98% identical, 12 lines differ
- plugin-creator — 98% identical, 12 lines differ
- plugin-creator — 98% identical, 12 lines differ
- plugin-creator — 98% identical, 12 lines differ
- plugin-creator — 98% identical, 18 lines differ
- plugin-creator — 98% identical, 12 lines differ
- plugin-creator — 98% identical, 12 lines differ
How it starts
The opening of the file, as written. The whole thing — 250 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.jsonwhen 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
What ships with it
10 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.
- agents/openai.yaml 339 B
- assets/plugin-creator-small.svg 1.3 KB
- assets/plugin-creator.png 1.5 KB
- references/installing-and-updating.md 5.9 KB
- references/plugin-json-spec.md 9.0 KB
- scripts/create_basic_plugin.py 11 KB runs code
- scripts/identifier_validation.py 784 B runs code
- scripts/read_marketplace_name.py 1.6 KB runs code
- scripts/update_plugin_cachebuster.py 3.0 KB runs code
- scripts/validate_plugin.py 21 KB runs code
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 · 250 lines · 86 tokens per session scan A 71b95b821964
plugin-creator is a skill published in the GitHub repository openai/codex (120,598 stars, last pushed today), licensed Apache-2.0. It adds 86 tokens to every session and 2,518 once invoked, about $0.0004 per session on Opus 5. 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 2026-08-30.
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