migration-plan

name	migration-plan
description	Generate a phased migration plan for framework, library, or architecture changes.
disable-model-invocation	true
allowed-tools	Read Grep Glob Bash(git *) Bash(find *) Bash(wc *)
arguments	["migration-description"]
argument-hint	migrate from Express to Fastify

Migration Plan

Generate a phased migration plan for framework, library, or architecture changes.

Step 1: Scope Assessment

1. Files affected: Find all files that reference the component being migrated.
2. Dependency chains: Map transitive dependencies that may be affected.
3. Risk profile: Assess complexity based on file count, test coverage, and integration depth.
4. Current usage patterns: Catalog how the component is used across the codebase.

Step 2: Interview User

Ask the user about:

1. Timeline: What is the target completion date?
2. Coexistence: Can old and new coexist during migration? For how long?
3. Constraints: Any files, modules, or features that cannot be migrated?
4. Rollback requirements: What rollback strategy is needed?

Step 3: Generate Plan

Create the migration plan at docs/migrations/{description}.md with:

Overview

• Migration scope and rationale
• Estimated effort and timeline
• Risk assessment summary

Phase 1: Preparation

• Set up the new framework/library alongside the old
• Create adapter layers for coexistence
• Establish migration validation criteria
• Dependencies, risks, verification steps, and rollback procedure

Phase 2: Incremental Migration

• Order of migration (least risky to most risky)
• For each component:
  • Files to change
  • Expected behavior changes
  • Test updates required
• Dependencies, risks, verification steps, and rollback procedure

Phase 3: Cleanup

• Remove old framework/library dependencies
• Remove adapter layers and compatibility shims
• Update documentation
• Dependencies, risks, verification steps, and rollback procedure

Each phase includes:

• Dependencies: What must be completed first
• Risks: What could go wrong
• Verification: How to confirm success
• Rollback: How to revert if needed