code-review-context

A set of rules for managing the message history sent to an AI model during coding work.

In plain words
What is it for?
It is for designing and reviewing how new information is added to the model context, including size limits and required code structures.
Why use it?
It helps keep the model's context predictable, bounded in size, and less likely to lose caching benefits after frequent changes.

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/openai/codex/code-review-context
Any agent
npx skills add openai/codex --skill code-review-context
Clone the repo
git clone --depth 1 https://github.com/openai/codex

Made for: Claude Code, Codex.

Per session 7 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 142 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00007 $0.00142
Opus 5 $0.00003 $0.00071
Sonnet 5 $0.00001 $0.00028
Haiku 4.5 $0.00001 $0.00014

Measured 2d ago against content hash 0af80b6388cc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

code-review-context 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.

Origin

Copies of this mod

8 near-identical copies found in the catalogue:

.codex/skills/code-review-context/SKILL.md · 13 lines

What it actually says

Codex maintains a context (history of messages) that is sent to the model in inference requests.

  1. No history rewrite - the context must be built up incrementally.
  2. Avoid frequent changes to context that cause cache misses.
  3. No unbounded items - everything injected in the model context must have a bounded size and a hard cap.
  4. No items larger than 10K tokens.
  5. Highlight new individual items that can cross >1k tokens as P0. These need an additional manual review.
  6. All injected fragments must be defined as structs in core/context and implement ContextualUserFragment trait
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. 2d ago First seen · 13 lines · 7 tokens per session scan A 0af80b6388cc

Subscribe to this mod's changes

code-review-context is a skill published in the GitHub repository openai/codex (120,598 stars, last pushed today), licensed Apache-2.0. It adds 7 tokens to every session and 142 once invoked, about $0.0000 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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