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 skills add sergekostenchuk/ui-ux-agent-skill-system --skill migration-plannergit clone --depth 1 https://github.com/sergekostenchuk/ui-ux-agent-skill-systemWrote 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/sergekostenchuk/ui-ux-agent-skill-system/migration-planner)<a href="https://agentmods.dev/skills/sergekostenchuk/ui-ux-agent-skill-system/migration-planner"><img src="https://agentmods.dev/badge/skills/sergekostenchuk/ui-ux-agent-skill-system/migration-planner/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/sergekostenchuk/ui-ux-agent-skill-system/migration-planner"><img src="https://agentmods.dev/badge/skills/sergekostenchuk/ui-ux-agent-skill-system/migration-planner.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00061 | $0.00575 |
| Opus 5 | $0.00030 | $0.00287 |
| Sonnet 5 | $0.00012 | $0.00115 |
| Haiku 4.5 | $0.00006 | $0.00057 |
Grade A, and why
migration-planner 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 10d 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 — 64 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Migration Planner
This skill creates a rollback-aware migration plan for existing sites. It is planning and validation-first, not a production mutation tool.
Operating Modes
url-map: map old URLs to new URLs and identify canonical decisions.redirect-plan: plan 301/302 rules without applying them.seo-surface: preserve titles, descriptions, headings, schema, sitemap, robots, llms.txt, and internal links.launch-checklist: define pre-launch, launch, and post-launch verification.rollback: prepare rollback, monitoring, and alert criteria.
Required Workflow
- Read references/migration-safety-contract.md.
- Start from
existing-site-analyzerevidence andrebuild-or-improve-advisordecision. - Use assets/migration-plan.template.md.
- Build a URL/change map:
- old URL;
- new URL;
- status;
- redirect type;
- canonical rule;
- metadata/schema preservation note.
- Add sitemap, robots, schema, internal links, llms.txt, analytics, and webmaster verification checks.
- Mark production actions as
Planneduntil the user explicitly approves deploy, DNS, redirects, GSC/webmaster, or server changes.
Safety Rules
- Do not apply redirects, edit robots/sitemap in production, deploy, change DNS, or submit GSC/webmaster changes without explicit approval.
- Do not store private analytics exports, tokens, cookies, or verification codes in the plan.
- Do not mark migration checks
Ranunless the command or artifact exists. - If high SEO risk remains, block launch handoff until rollback and monitoring are defined.
Handoff Shape
Migration mode:
Decision source:
URL map path:
Redirect plan:
SEO surface preservation:
Launch approvals needed:
Rollback plan:
Monitoring:
Next owner:
Checks:
Validation
When editing this skill, run:
python3 $CODEX_HOME/skills/.system/skill-creator/scripts/quick_validate.py $CODEX_HOME/skills/migration-planner
python3 $CODEX_HOME/skills/senior-skill-architect/scripts/lint_production_skill.py $CODEX_HOME/skills/migration-planner
python3 -m json.tool $CODEX_HOME/skills/migration-planner/evals/evals.json >/dev/null
What ships with it
4 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.
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.
- 10d ago First seen · 64 lines · 61 tokens per session scan A e66cb7f6cf08
migration-planner is a skill published in the GitHub repository sergekostenchuk/ui-ux-agent-skill-system (23 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 61 tokens to every session and 575 once invoked, about $0.0003 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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