migration-strategy

migration-strategy is a skill for Claude Code from sethdford/claude-skills. It costs 25 tokens per session (232 once invoked), scanned A, original, MIT.

A planning guide for moving a large system from older technology to a new architecture. It breaks the work into smaller phases instead of replacing everything at once.

In plain words
What is it for?
Use it to assess the current system, define the target architecture, identify migration boundaries, plan phases, manage risks, and set success measures.
Why use it?
It helps reduce disruption and makes it easier to test each stage, run old and new systems together, and recover if a phase fails.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the decision-making plugin — 8 skills, 3 commands shipped together

Good fit Use it to assess the current system, define the target architecture, identify migration boundaries, plan phases, manage risks, and set success measures.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sethdford/claude-skills/migration-strategy
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.

Any agent
npx skills add sethdford/claude-skills --skill migration-strategy
Clone the repo
git clone --depth 1 https://github.com/sethdford/claude-skills

Made for: Claude Code.

Or install decision-making, the plugin that ships this one along with the rest of its 8 skills, 3 commands.

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-strategy

README.md
[![agentmods](https://agentmods.dev/badge/skills/sethdford/claude-skills/migration-strategy/github.svg)](https://agentmods.dev/skills/sethdford/claude-skills/migration-strategy)
Your own site
<a href="https://agentmods.dev/skills/sethdford/claude-skills/migration-strategy"><img src="https://agentmods.dev/badge/skills/sethdford/claude-skills/migration-strategy/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.

agentmods 80×15 button for migration-strategy

Your own site · 80×15
<a href="https://agentmods.dev/skills/sethdford/claude-skills/migration-strategy"><img src="https://agentmods.dev/badge/skills/sethdford/claude-skills/migration-strategy.svg" alt="Reviewed on agentmods" width="80" 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 232 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00025 $0.00232
Opus 5 $0.00013 $0.00116
Sonnet 5 $0.00005 $0.00046
Haiku 4.5 $0.00003 $0.00023

Measured 10d ago against content hash e9fe9ff9d848, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

migration-strategy 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.

architect/decision-making/skills/migration-strategy/SKILL.md · 28 lines

What it actually says

Migration Strategy

Plan phased migrations that minimize risk and disruption while delivering value incrementally.

Instructions

  1. Assess Current State: What's working? What's broken?
  2. Define Target State: New architecture vision
  3. Identify Seams: Where can you break the system into phases?
  4. Plan Phases: Each phase delivers value; takes weeks to months
  5. Risk Mitigation: Parallel running, feature flags, rollback plans
  6. Success Metrics: How do we measure success of each phase?

Anti-Patterns

  • Big Bang Rewrite: Replace everything at once. Result: chaos and failure. Guard: Incremental, staged migration.
  • No Parallel Running: Migrate directly without validation. Guard: Run old and new in parallel, validate.

Further Reading

  • Strangler Fig Pattern — incremental replacement
  • Monolith to Microservices by Sam Newman
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. 10d ago First seen · 28 lines · 25 tokens per session scan A e9fe9ff9d848

Subscribe to this mod's changes

migration-strategy is a skill published in the GitHub repository sethdford/claude-skills (40 stars, last pushed 6mo ago), licensed MIT. It adds 25 tokens to every session and 232 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 2026-08-30.