migration-planner

migration-planner is a skill for Claude Code, Codex from JansenAnalytics/claudex. It costs 25 tokens per session (430 once invoked), scanned A, original, MIT.

Plan and execute framework, language, or infrastructure migrations safely: version upgrades, framework swaps, API 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/jansenanalytics/claudex/migration-planner
Any agent
npx skills add JansenAnalytics/claudex --skill migration-planner
Clone the repo
git clone --depth 1 https://github.com/JansenAnalytics/claudex

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for migration-planner

README.md
[![agentmods](https://agentmods.dev/badge/skills/jansenanalytics/claudex/migration-planner.svg)](https://agentmods.dev/skills/jansenanalytics/claudex/migration-planner)
Your own site
<a href="https://agentmods.dev/skills/jansenanalytics/claudex/migration-planner"><img src="https://agentmods.dev/badge/skills/jansenanalytics/claudex/migration-planner.svg" alt="Measured on agentmods" height="20"></a>
Per session 25 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 430 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00025 $0.00430
Opus 5 $0.00013 $0.00215
Sonnet 5 $0.00005 $0.00086
Haiku 4.5 $0.00003 $0.00043

Measured today against content hash a0bc21e41c28, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 today.

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.

skills/migration-planner/SKILL.md · 55 lines

What it actually says

migration-planner

Plan and execute framework, language, or infrastructure migrations safely: version upgrades, framework swaps, API changes.

When to Use

  • Upgrading Node.js or Python versions
  • Migrating between frameworks (Express→Fastify, React→Next.js, etc.)
  • Planning database migrations
  • Modernizing legacy codebases
  • Any breaking-change upgrade

How It Works

  1. Run checklist-gen.sh to generate a migration checklist for your scenario
  2. Use breaking-changes.sh to scan for potential breaking changes
  3. Use rollback-plan.sh to generate a rollback plan
  4. Consult references for common patterns and anti-patterns

Scripts

Script Purpose
checklist-gen.sh Generate a migration checklist for a specific migration type
breaking-changes.sh Detect potential breaking changes between versions/frameworks
rollback-plan.sh Generate a rollback plan template

References

File Content
common-migrations.md Common migration paths with tips
anti-patterns.md Migration anti-patterns to avoid

Example Usage

# Generate a migration checklist
bash scripts/checklist-gen.sh --from "node16" --to "node20" --type runtime

# Detect breaking changes in package.json
bash scripts/breaking-changes.sh --path /path/to/project --from "16.0.0" --to "20.0.0"

# Generate rollback plan
bash scripts/rollback-plan.sh --name "Node 20 upgrade" --steps "Update .nvmrc,Update CI config,Update Dockerfile" --output rollback.md
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. today First seen · 55 lines · 25 tokens per session scan A a0bc21e41c28

Subscribe to this mod's changes

migration-planner is a skill published in the GitHub repository JansenAnalytics/claudex (5 stars, last pushed 2mo ago), licensed MIT. It adds 25 tokens to every session and 430 once invoked, about $0.0001 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 2026-09-03.

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