migration-loop

migration-loop is a skill for Claude Code, Codex from ivy00johns/Skill-Madness. It costs 207 tokens per session (3,361 once invoked), scanned A, original, MIT.

A controlled workflow for migrating a fixed, listed set of code targets one at a time until none remain. A migration changes code from an old pattern or interface to a new one.

In plain words
What is it for?
Use it for repeated code changes such as API upgrades, framework or import renames, codemods, and test-framework replacements, with tests and searches confirming completion.
Why use it?
It provides checkpoints and verification so each change preserves behavior and the old pattern is demonstrably gone.

Skill for Claude CodeCodex

Part of the skill-madness plugin — 56 skills 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/ivy00johns/skill-madness/migration-loop
Any agent
npx skills add ivy00johns/Skill-Madness --skill migration-loop
Clone the repo
git clone --depth 1 https://github.com/ivy00johns/Skill-Madness

Made for: Claude Code, Codex.

Or install skill-madness, the plugin that ships this one along with the rest of its 56 skills.

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-loop

README.md
[![agentmods](https://agentmods.dev/badge/skills/ivy00johns/skill-madness/migration-loop.svg)](https://agentmods.dev/skills/ivy00johns/skill-madness/migration-loop)
Your own site
<a href="https://agentmods.dev/skills/ivy00johns/skill-madness/migration-loop"><img src="https://agentmods.dev/badge/skills/ivy00johns/skill-madness/migration-loop.svg" alt="Measured on agentmods" height="20"></a>
Per session 207 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,361 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 $0.00207 $0.03361
Opus 5 $0.00103 $0.01681
Sonnet 5 $0.00041 $0.00672
Haiku 4.5 $0.00021 $0.00336

Measured 4d ago against content hash d773cbf5992b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

migration-loop 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 4d 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.

skills/loops/migration-loop/SKILL.md · 231 lines

How it starts

The opening of the file, as written. The whole thing — 231 lines — stays where its author put it; the contents beside it link to each section on GitHub.

migration-loop

A configuration of [loop-controller]. That skill supplies the loop machinery — primitive selection, the full guardrail stack, state externalization. This skill supplies the two things specific to "migrate a fixed set of targets to completion": a default-FAIL target checklist driven one entry per iteration, and a proof that no legacy pattern remains (a grep for the old pattern returning zero), not merely "tests pass." Read loop-controller for the guardrails; they're inherited, not repeated here.

Why disable-model-invocation: this loop edits and commits code on its own — a checkpoint commit per migrated target — until the whole set is done. You want to type /migration-loop (or have the orchestrator dispatch it) — not have Claude silently start rewriting every file because it noticed an old API.

The 5-part contract

Part This loop
trigger a finite, enumerable set of targets needs the same transform (a codemod, a Jest-to-Vitest swap, an API version bump, a framework/import rename), plus a way to verify behaviour is preserved — or an explicit /migration-loop (optionally scoped to one path)
action ONE iteration: pick the next "migrated": false target from the checklist → apply the transform to just that target → run the suite to confirm behaviour-identical → on green, commit a checkpoint naming the target → flip its checklist entry to true
proof EVERY checklist entry "migrated": true AND the full suite exits 0 AND a grep for the legacy pattern returns zero matches — default-FAIL: assume incomplete until all three artifacts (the checklist, the suite exit code, the grep count) are observed together
memory migration-checklist.json (one default-FAIL entry per target + the old→new mapping), PROGRESS.md (what's migrated / next), a git checkpoint commit per migrated target
stop all three proof artifacts hold OR iteration cap OR no-progress for 3 rounds OR budget cap OR an HITL checkpoint for an irreversible target (see Guardrails)

Read the full file on GitHub · 231 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 4d ago First seen · 231 lines · 207 tokens per session scan A d773cbf5992b

Subscribe to this mod's changes

migration-loop is a skill published in the GitHub repository ivy00johns/Skill-Madness (11 stars, last pushed 24d ago), licensed MIT. It adds 207 tokens to every session and 3,361 once invoked, about $0.0010 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.

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