conventions-codex

A Codex CLI reference skill for the file formats and conventions used to configure Codex projects and plugins. It covers settings, skills, hooks, agents, project instruction files, and marketplace metadata.

In plain words
What is it for?
Use it when creating or reviewing `.codex` configuration, `.agents/skills` directories, plugin manifests, hooks, `AGENTS.md`, marketplace files, or agent sidecar metadata.
Why use it?
It helps prevent configuration mistakes caused by assuming Codex uses the same layout or syntax as another coding agent. It also records the Codex-specific rules needed when scoring or writing these files.

Skill for Claude CodeCodex

Part of the nlpm plugin — 17 skills, 12 commands, 8 agents, 1 hook shipped together

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/xiaolai/nlpm/conventions-codex
Any agent
npx skills add xiaolai/nlpm --skill conventions-codex
Clone the repo
git clone --depth 1 https://github.com/xiaolai/nlpm

Made for: Claude Code, Codex.

Or install nlpm, the plugin that ships this one along with the rest of its 17 skills, 12 commands, 8 agents, 1 hook.

Per session 88 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,769 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 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 $0.00088 $0.04769
Opus 5 $0.00044 $0.02384
Sonnet 5 $0.00018 $0.00954
Haiku 4.5 $0.00009 $0.00477

Measured 3d ago against content hash bd81b49cac5a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

conventions-codex scanned grade B 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 3d 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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

| Config | `.codex/config.toml` (trust-gated) | `~/.codex/config.toml` |
codex/skills/conventions-codex/SKILL.md · 261 lines

How it starts

The opening of the file, as written. The whole thing — 261 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Codex CLI Conventions

Tool-specific overlay for OpenAI Codex CLI artifacts. Loaded by the scorer and checker when an artifact is classified as Tier 2-Codex (per agents/scorer.md step 3). The universal floor lives in nlpm:conventions; this overlay adds Codex-specific schemas on top.

Primary authoritative sources:


1. File system layout

Codex separates the cross-tool surface (.agents/) from the Codex-private surface (.codex/). The Claude Code mental model of "everything under one tool directory" does not transfer.

Artifact Project scope User scope
Skills .agents/skills/<name>/SKILL.md (CWD→repo-root scan) ~/.agents/skills/, admin /etc/codex/skills/
Plugin manifest <plugin-root>/.codex-plugin/plugin.json
Marketplace .agents/plugins/marketplace.json (+ legacy .claude-plugin/marketplace.json) ~/.agents/plugins/marketplace.json
AGENTS.md Git root → CWD; per dir AGENTS.override.mdAGENTS.md → fallback (one file/dir; closer overrides earlier) ~/.codex/AGENTS.override.md, ~/.codex/AGENTS.md
Config .codex/config.toml (trust-gated) ~/.codex/config.toml
Hooks .codex/hooks.json OR inline [hooks] in config.toml ~/.codex/hooks.json
Slash commands / prompts — (not project-shareable) ~/.codex/prompts/<name>.md
MCP servers [mcp_servers.<id>] table inside config.toml same
Skill sidecar (Codex-specific) <skill>/agents/openai.yaml next to SKILL.md

Read the full file on GitHub · 261 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. 3d ago First seen · 261 lines · 88 tokens per session scan B bd81b49cac5a

Subscribe to this mod's changes

conventions-codex is a skill published in the GitHub repository xiaolai/nlpm (133 stars, last pushed 3d ago), licensed ISC. It adds 88 tokens to every session and 4,769 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

brainstorming

You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.

obra/superpowers · 37 tokens

auto-perf-optimize

Run agent-driven VS Code performance or memory investigations. Use when asked to launch Code OSS, automate a VS Code scenario, run the Chat memory smoke runner, capture renderer heap snapshots, take workflow screenshots, compare run summaries, or drive a repeatable scenario before heap-snapshot analysis.

microsoft/vscode · 62 tokens

chat-perf

Run chat perf benchmarks and memory leak checks against the local dev build or any published VS Code version. Use when investigating chat rendering regressions, validating perf-sensitive changes to chat UI, or checking for memory leaks in the chat response pipeline.

microsoft/vscode · 51 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens