migration-guidance

migration-guidance is a skill for Claude Code, Codex from lootlog/monorepo. It costs 33 tokens per session (234 once invoked), scanned A, a copy of migration-guidance, MIT.

Guidance for documenting how a public programming interface changes between version 3 and version 4. It updates migration notes when functions or modules are renamed, moved, removed, replaced, or materially changed.

In plain words
What is it for?
Use it to edit migration annotations, verify replacement APIs against code and tests, or regenerate the version-3-to-version-4 guide.
Why use it?
It helps people upgrading between major versions understand what changed and prevents affected version-3 interfaces from being omitted from the migration reference.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it to edit migration annotations, verify replacement APIs against code and tests, or regenerate the version-3-to-version-4 guide.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/lootlog/monorepo/migration-guidance
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 lootlog/monorepo --skill migration-guidance
Clone the repo
git clone --depth 1 https://github.com/lootlog/monorepo

Made for: Claude Code, Codex.

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-guidance

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/lootlog/monorepo/migration-guidance"><img src="https://agentmods.dev/badge/skills/lootlog/monorepo/migration-guidance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 234 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 100% copy Near-identical to another mod 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 $0.00033 $0.00234
Opus 5.5 $0.00013 $0.00094
Sonnet 5.5 $0.00007 $0.00047
Haiku 4.5 $0.00003 $0.00023

Measured 1mo ago against content hash 90976b6b5b39, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

migration-guidance 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 1mo 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.

Origin

This is a copy

100% identical to migration-guidance — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

repos/effect/.agents/skills/migration-guidance/SKILL.md · 22 lines

What it actually says

Update guidance when a v3 public module or API is renamed, moved, removed, replaced, or gains a materially different v4 contract. A v4-only API without a v3 counterpart does not automatically need an annotation.

  1. Account for every affected v3 symbol.
  2. Read annotations.md before adding or changing annotation YAML. Verify every suggested replacement against implementation and tests.
  3. When checking or regenerating the reference, or when the API change exists in a committed ref, read generation.md. Otherwise report that generation is deferred.
  4. When output was generated, inspect it for unrelated movement and stale refs.

The task is complete when every affected v3 symbol is accounted for, annotation replacements are verified, checks and generation succeed when the change is in a committed ref, and every generated difference is explained. Report deferred checks explicitly for uncommitted API changes.

Files

What ships with it

2 files 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. 1mo ago First seen · 22 lines · 33 tokens per session scan A 90976b6b5b39

Subscribe to this mod's changes

migration-guidance is a skill published in the GitHub repository lootlog/monorepo (29 stars, last pushed today), licensed MIT. It adds 33 tokens to every session and 234 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to migration-guidance, differing in 0 lines, and is treated as a copy.

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