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/letitbk/claude-academic-setup/codexnpx skills add letitbk/claude-academic-setup --skill codexgit clone --depth 1 https://github.com/letitbk/claude-academic-setupWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/letitbk/claude-academic-setup/codex)<a href="https://agentmods.dev/skills/letitbk/claude-academic-setup/codex"><img src="https://agentmods.dev/badge/skills/letitbk/claude-academic-setup/codex.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00048 | $0.03337 |
| Opus 5 | $0.00024 | $0.01669 |
| Sonnet 5 | $0.00010 | $0.00667 |
| Haiku 4.5 | $0.00005 | $0.00334 |
Grade A, and why
codex 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 394 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Codex Review & Second Opinion Skill
Use OpenAI's Codex CLI to get code reviews, plan evaluations, and second opinions. This provides an independent AI perspective using GPT-5.5 or o3 models.
When to Use This Skill
Trigger when user:
- Uses
/codexcommand explicitly - Asks for a "code review"
- Wants to "evaluate a plan" or "check my implementation plan"
- Wants a "second opinion" on code or approach
- Says "review this", "check this code", "validate this"
- Asks "what do you think about this implementation"
- Wants to "double check" code changes
- Requests "another perspective" on code
Prerequisites
Codex CLI must be installed and authenticated:
# Check installation
which codex
# Login if needed
codex login
Prompt Rules
Follow these when constructing Codex prompts. Better prompts beat higher reasoning effort.
- Use XML-tagged prompt blocks — give Codex a
<task>, an output contract, and grounding rules instead of bare string instructions. - Don't be vague — "take a look at this" produces vague output. State what you want evaluated and what shape the answer should take.
- Don't mix unrelated jobs — review in one run, fix in another, docs in a third. One clear task per Codex invocation.
- Don't ask for "more reasoning" — tighten the output contract or add a
<verification_loop>instead of saying "think harder." - Separate facts from inferences — always include
<grounding_rules>so Codex labels speculation explicitly. - Specify output shape — tell Codex exactly what sections to return. Structured output is easier to act on.
Guardrail
After presenting Codex findings, STOP. Do not make any code changes. Do not fix any issues. Ask the user which issues, if any, they want fixed before touching a single file. Auto-applying fixes from a review is strictly forbidden, even if the fix is obvious.
Workflow
Step 1: Determine What to Review
ALWAYS ask the user what they want reviewed:
Use AskUserQuestion to clarify:
- Scope: What should be reviewed?
- Uncommitted changes (staged/unstaged)
- Specific file(s)
- Changes against a branch
- A specific commit
- An implementation plan
- General approach/implementation question
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.
- 4d ago First seen · 394 lines · 48 tokens per session scan A 2a755a3d04de
codex is a skill published in the GitHub repository letitbk/claude-academic-setup (43 stars, last pushed 2mo ago), licensed MIT. It adds 48 tokens to every session and 3,337 once invoked, about $0.0002 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.
Other skills, from other repositories
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
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.
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.
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.
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.
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…