Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add anhnguyen0905/codex-mcp/plugin install codex-flowWrote 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/anhnguyen0905/codex-mcp/skill-selection)<a href="https://agentmods.dev/skills/anhnguyen0905/codex-mcp/skill-selection"><img src="https://agentmods.dev/badge/skills/anhnguyen0905/codex-mcp/skill-selection.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 5.1 | $0.00087 | $0.05448 |
| Opus 5 | $0.00044 | $0.02724 |
| Sonnet 5 | $0.00017 | $0.01090 |
| Haiku 4.5 | $0.00009 | $0.00545 |
Grade B, and why
skill-selection 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 7d 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.
`grep -ril "<term>" ~/.claude/plugins/cache/*/*/*/skills --include=SKILL.md` How it starts
The opening of the file, as written. The whole thing — 311 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill Selection (index-first, never blind-load)
Loading every available skill wastes context and buries the ones that matter. Select the few relevant skills from a local index; treat "0 matches" as a normal outcome. A session should only ever contain the skills its current work needs.
Step 1 — Locate the index
- Path:
$CODEX_FLOW_SKILLS_INDEXif set, else~/.claude/skill-library/INDEX.md. - Missing or stale (skills were added since it was rebuilt)? Rebuild it:
node "${CLAUDE_PLUGIN_ROOT}/scripts/build-skills-index.mjs" [extra skill dirs ...]— defaults scan~/.claude/skills,~/claude-skill-library(including promoted skills underremote/), and theskills/dir of every installed plugin (~/.claude/plugins/cache/<marketplace>/<plugin>/<newest version>/skills), then merge theREMOTE.mdpointer catalog for anything not yet local. Installed plugin skills are trusted and load by name — an index that omits them makes selection claim a gap the machine already fills. - Sanity-check the count before trusting a "no match": an index with only a few dozen entries
almost certainly predates the plugin scan. Rebuild, then match again.
Anything under a
quarantine/directory (where--clonelands third-party repos) is NEVER indexed — quarantined skills only become visible through the explicit vet step in Step 5. - Still no index → skip selection, continue the phase with its named
codex-flow:*skills only, and tell the user once how to enable the local-first setup:node "${CLAUDE_PLUGIN_ROOT}/scripts/sync-awesome-skills.mjs" --clonethen rebuild the index. - The library dir (
~/claude-skill-library) must stay OUTSIDE auto-discovered skill dirs — skills on disk cost zero context until selected; only what you load enters the session.
Step 2 — Classify the request, then derive search terms
Requests are not always engineering. First identify 1–2 role facets the task actually needs:
| Facet | Examples of terms it generates |
|---|---|
| Engineering | language (python, typescript…), framework (django, react…), storage (postgres, redis…), domain (auth, payments, migrations, e2e, performance…) |
| Data / analytics | pandas, statistics, cohort, retention, funnel, segmentation, forecasting, experiment, significance |
| Data engineering | sql, warehouse, star schema, dbt, etl, orchestration, event taxonomy, data quality, reconciliation |
| Visualization / reporting | chart, palette, dashboard, slides/pptx, spreadsheet/xlsx, infographic, executive summary |
| Marketing / content | campaign, positioning, messaging, copywriting, seo, landing page, social, brand voice, content calendar, launch |
| Growth / paid media | roas, cpi, cac, ltv, payback, attribution, incrementality, bidding, media plan, creative fatigue, aso |
| Research | market sizing, competitor, benchmark, survey design, cross-tab, persona, interview, scenario / what-if |
| Product / planning | prd, roadmap, backlog, prioritization, metrics, kpi tree, okr, pricing, unit economics |
| Finance / BizOps | business case, budget allocation, forecast, margin, sensitivity, sop |
| Accounting / audit | bookkeeping, journal entry, reconciliation, chart of accounts, accrual, month-end close, P&L, balance sheet, VAT, invoice, trial balance, audit, materiality, sampling, internal controls, workpapers |
| Personal finance | household budget, emergency fund, debt payoff, savings rate, compound interest, retirement, net worth, insurance |
| SME / operations | small business, pricing, break-even, cash flow, runway, working capital, supplier terms, inventory, sop, production scheduling, capacity, quality |
| Sales / support / CRM | pipeline, lead qualification, quota, forecast, win/loss, crm, ticket triage, sla, csat, nps, escalation, knowledge base |
| HR / people | recruiting, job description, structured interview, onboarding, compensation, performance review, engagement survey, attrition, headcount |
| Legal / compliance | contract review, nda, clause, termination, liability, indemnification, redline, compliance, data privacy, customs |
| Design / UX | ui, ux research, persona, usability testing, user flow, wireframe, information architecture, accessibility, motion, design system, typography |
| Education / training | learning objectives, curriculum, syllabus, lesson plan, assessment, rubric, e-learning, workshop, skill gap |
| Real estate | rental yield, cap rate, noi, cash-on-cash, mortgage, amortization, buy vs rent, occupancy, vacancy |
| Logistics / supply chain | carrier, freight, customs, hs code, incoterms, shipment exception, returns, reverse logistics, demand planning, safety stock, warehouse |
| Localization | translation, locale, tone preservation, market adaptation |
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.
- 7d ago First seen · 311 lines · 87 tokens per session scan B 8b05bb09adf7
skill-selection is a skill published in the GitHub repository anhnguyen0905/codex-mcp (3 stars, last pushed 5d ago), licensed MIT. It adds 87 tokens to every session and 5,448 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 2026-08-31.
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