migration

migration is a skill for Claude Code, Codex from arbazkhan971/godmode. It costs 8 tokens per session (1,203 once invoked), scanned A, original, MIT.

A guide for moving software from one language, framework, architecture, or data system to another. It compares approaches such as replacing everything at once, running old and new systems together, or migrating piece by piece.

In plain words
What is it for?
Use it to plan framework or language upgrades, monolith-to-service transitions, data migrations, and gradual replacement of existing components.
Why use it?
Large technology changes can cause downtime, data errors, or an unmanageable amount of work. It helps choose a migration approach based on system size, risk, testing, and team capacity.

Skill for Claude CodeCodex

Part of the godmode plugin — 133 skills, 1 command, 9 agents, 3 MCP servers shipped together

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/arbazkhan971/godmode/migration
Any agent
npx skills add arbazkhan971/godmode --skill migration
Clone the repo
git clone --depth 1 https://github.com/arbazkhan971/godmode

Made for: Claude Code, Codex.

Or install godmode, the plugin that ships this one along with the rest of its 133 skills, 1 command, 9 agents, 3 MCP servers.

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/arbazkhan971/godmode/migration.svg)](https://agentmods.dev/skills/arbazkhan971/godmode/migration)
Your own site
<a href="https://agentmods.dev/skills/arbazkhan971/godmode/migration"><img src="https://agentmods.dev/badge/skills/arbazkhan971/godmode/migration.svg" alt="Measured on agentmods" height="20"></a>
Per session 8 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,203 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00008 $0.01203
Opus 5 $0.00004 $0.00602
Sonnet 5 $0.00002 $0.00241
Haiku 4.5 $0.00001 $0.00120

Measured yesterday against content hash f2441b948a22, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

migration 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 yesterday.

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/SKILL.md · 158 lines

How it starts

The opening of the file, as written. The whole thing — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Activate When

  • /godmode:migration, "migrate from X to Y"
  • "convert to TypeScript", "move to microservices"
  • "upgrade from React 17 to 19", "strangler fig"

Workflow

1. Migration Assessment

Source: <language, framework, architecture, data stores>
Target: <target stack and architecture>
Code size: <files, LOC, modules>
Test coverage: <percentage>
Team size: <N developers>
Type: Language | Framework | Architecture | Data | API
IF codebase > 50K LOC: use Strangler Fig (not Big Bang)
IF data-critical: use Parallel Run
IF internal component swap: use Branch by Abstraction

2. Strategy Selection

BIG BANG: rewrite all, switch over
  WHEN: <10K LOC, acceptable downtime
  Risk: HIGH — all-or-nothing
STRANGLER FIG: replace piece by piece via facade
  WHEN: large codebase, zero-downtime required
  Risk: LOW — each piece reversible
PARALLEL RUN: old+new simultaneously, compare
  WHEN: data integrity critical
  Risk: MEDIUM — double infra cost
BRANCH BY ABSTRACTION: abstraction layer, swap impl
  WHEN: internal component, same API contract
  Risk: LOW — abstraction isolates change

IF team < 3: avoid Big Bang (too risky with small team). IF match_rate < 99.0%: do NOT cutover. IF match_rate >= 99.9%: ramp 5% -> 25% -> 50% -> 100%.

3. Language/Framework Planning

JS -> TS: Phase 1: tsconfig with allowJs:true, strict:false Phase 2: Rename .js->.ts one file at a time (leaves first) Phase 3: Enable strict mode incrementally

REST -> GraphQL: Phase 1: GraphQL alongside REST (resolvers call services) Phase 2: Migrate clients one feature at a time Phase 3: Deprecate REST endpoints

Monolith -> Microservices: Phase 0: Identify bounded contexts, add module boundaries Phase 1: Extract easiest module as first service Phase 2: Feature flag, shadow traffic, ramp

4. Zero-Downtime Data Migration

Phase 1 — Dual-write: write BOTH stores, old=source
Phase 2 — Backfill: batch historical data, rate-limited
  Track: migrated/total, verify integrity per batch
Phase 3 — Cutover: read from new, stop old writes
Phase 4 — Cleanup: remove old after 2-week stability
# Verify data integrity
psql -c "SELECT count(*) FROM old_table"
psql -c "SELECT count(*) FROM new_table"
# Row counts must match within 0.01%

Read the full file on GitHub · 158 lines

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. yesterday First seen · 158 lines · 8 tokens per session scan A f2441b948a22

Subscribe to this mod's changes

migration is a skill published in the GitHub repository arbazkhan971/godmode (26 stars, last pushed 7d ago), licensed MIT. It adds 8 tokens to every session and 1,203 once invoked, about $0.0000 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.

Related

Other skills, from other repositories

jobs-to-be-done

Discover what customers truly need by analyzing the "job" they hire your product to do. Use when the user mentions "customer discovery", "why customers churn", "what job does this solve", "competing against luck", "product-market fit", "switching behavior", "milkshake moment", or "functional vs emotional jobs". Also…

wondelai/skills · 137 tokens

asc-subscription-localization

Bulk-localize subscription, subscription-group, and in-app purchase display names across App Store locales using asc, including API 4.4.1 version-scoped v2 resources. Use when filling or updating subscription/IAP names and descriptions without App Store Connect UI work.

rorkai/app-store-connect-cli-skills · 60 tokens

codex

Run benchmark-selected GPT-5.6 work through the Codex CLI.

notque/vexjoy-agent · 18 tokens

scienceworld-growth-focuser

Use when you have planted a seed or need to track a plant's growth stage (sprouting, flowering, reproduction). Applies the 'focus on' action to a specific plant or biological entity to signal intent and monitor its development. Trigger after planting or when you need to observe life cycle progression in the…

zjunlp/SkillNet · 71 tokens

iterate-pivot-decision

Documents a strategic pivot or persevere decision with the evidence, analysis, and rationale. Use when evaluating whether to change direction on a product, feature, or strategy based on market feedback.

product-on-purpose/pm-skills · 43 tokens

ralph-specum-requirements

This skill should be used only when the user explicitly asks to use $ralph-specum-requirements, or explicitly asks Ralph Specum in Codex to run the requirements phase.

tzachbon/smart-ralph · 45 tokens