# Migration

> Use when data, schema, API, dependency, platform, infrastructure, or runtime state must move between versions or systems while preserving service and recoverability.

- Skill: `nono911/migration` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add nono911/migration`
- Raw SKILL.md: https://api.skillmd.com/api/skills/nono911/migration/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: nono911 (https://skillmd.com/u/nono911)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/nono911/migration

---


# Migration

## Purpose

Design or execute a staged, observable, reversible transition with explicit compatibility windows, validation, and cleanup.

## Workspace protocol

Read `references/workspaces.md` once per agent task before selecting or creating workflow artifacts; reuse it unless repository scope or task authority changes. This skill owns only the task-specific behavior below.

## Inputs

- Source and target states, invariants, data volume, traffic, and downtime tolerance
- Producers, consumers, schemas, deployment topology, ownership, and operational constraints
- Backfill, rollback, compliance, and retention requirements

## Outputs

- Migration phases, compatibility strategy, validation, monitoring, rollback, and cleanup criteria
- If execution is authorized: migrations, adapters, backfills, tests, and runbook changes
- Reconciliation evidence and remaining risk

## Rules

- Inspect all readers and writers before changing shared state.
- Prefer expand-migrate-contract for live systems: introduce compatibility, move traffic or data, verify, then remove old paths.
- Make reruns idempotent and define partial-failure recovery.
- Validate counts plus business invariants; do not treat command success as data correctness.
- Separate source implementation from production execution authorization.
- Preserve backups and rollback paths appropriate to impact.

## Decision-log updates

Record compatibility windows, cutover criteria, data ownership, transformation rules, rollback limits, accepted downtime, and irreversible checkpoints. Link evidence for completing each phase.
When durable state is approved, append compatibility, sequencing, rollback, and point-of-no-return choices to the selected work item's decisions.md; otherwise include them in the final response.

## Escalate to the human

Escalate before destructive or irreversible steps, production backfills or cutovers, downtime, data loss or semantic ambiguity, privacy-sensitive movement, or rollback beyond the stated tolerance.