author-migration

author-migration is a skill for Claude Code, Codex from nrwl/nx. It costs 176 tokens per session (10,204 once invoked), scanned A, original, MIT.

A guide for writing Nx upgrade migrations, which are automated changes applied when an Nx workspace moves between versions. Nx is a build and development tool for managing projects, including workspaces with multiple packages.

In plain words
What is it for?
Use it to decide whether a change needs a migration, choose the correct migration type, and create the related migration files and tests.
Why use it?
It helps prevent existing workspaces from breaking when options, defaults, dependencies, or other supported settings change.

Skill for Claude CodeCodex

View the source file nrwl/nx
About the project

Nx is a tool for managing monorepos, which are repositories containing multiple related projects, across TypeScript and other languages. It helps development teams and AI agents run only affected tasks, cache build results, generate code, and coordinate continuous integration. The catalogue add-ons provide agent skills, commands, agents, instructions, and settings for working with Nx.

nrwl/nx · 29,304 stars · on GitHub

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

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 author-migration

README.md
[![agentmods](https://agentmods.dev/badge/skills/nrwl/nx/author-migration.svg)](https://agentmods.dev/skills/nrwl/nx/author-migration)
Your own site
<a href="https://agentmods.dev/skills/nrwl/nx/author-migration"><img src="https://agentmods.dev/badge/skills/nrwl/nx/author-migration.svg" alt="Measured on agentmods" height="20"></a>
Per session 176 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 10,204 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 $0.00176 $0.10204
Opus 5 $0.00088 $0.05102
Sonnet 5 $0.00035 $0.02041
Haiku 4.5 $0.00018 $0.01020

Measured 5d ago against content hash 22637b90cebd, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

author-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 5d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/compute-target-versions.mjs), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.claude/skills/author-migration/SKILL.md · 218 lines

How it starts

The opening of the file, as written. The whole thing — 218 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Author a first-party Nx migration

Companion files in this directory:

  • runtime-contract.md: how nx migrate consumes every migrations.json key. Read it before wiring an entry; most authoring mistakes are wrong assumptions about this contract.
  • deprecated-patterns.md: patterns to never reproduce, with recognition signatures. Read it before copying from an existing migration or from git history.
  • templates/: entry shapes, spec skeleton, and the two .md genres.

1. Decompose the change into migration needs

Enumerate every breaking or behavior-changing item in the change (upstream changelog, upstream migration guide, upstream repo's own migrations directory, or the Nx-internal change itself). Classify each item with exactly one treatment:

Treatment When Shape
Nothing Additive change, a plugin-absorbed break, or a shape no Nx surface produces (prose below) No entry
Version admission Nx starts supporting a new upstream major, even when the previous major stays supported packageJsonUpdates group gated on the source-major window; nx migrate moves willing workspaces onto the latest supported major (see packages/storybook/migrations.json key 22.1.0, shipped while v8 stayed supported, and packages/vite key 21.5.0)
Plain bump Dependency versions change, nothing else Declarative packageJsonUpdates. Never write a .ts implementation for an unconditional bump
Conditional dep change Add/remove/swap a dependency based on workspace state .ts implementation using addDependenciesToPackageJson / removeDependenciesFromPackageJson (add side: see packages/angular/src/migrations/update-23-1-0/add-angular-build.ts; copy its dependency handling, not its utils/versions import)
Source transform Deterministic, statically detectable source or config change (removed option, key rename, default flip) implementation + spec + documentation .md
Ported upstream migration Upstream ships its own migrations for the major (wins over Source transform for those items; a judgment-based upstream migration takes the Prompt-only/Hybrid shape) One generator-only migration per upstream migration, description ending "matching the X migration", requires on the new major (see packages/angular/migrations.json update-23-1-0-add-trust-proxy-headers)
Run upstream codemod Upstream publishes an npx-runnable codemod Prompt migration instructing the agent to run it; do not port it (see packages/react/src/migrations/update-23-1-0/ai-instructions-for-react-19.md)
Prompt-only Change requires judgment an AST transform cannot make prompt .md plus documentation .md, no implementation
Hybrid Mechanical pre-pass plus judgment ONE entry with both implementation and prompt (see eslint update-23-1-0-convert-to-flat-config; do not copy its shared .md basename)

Read the full file on GitHub · 218 lines

Files

What ships with it

7 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. 5d ago First seen · 218 lines · 176 tokens per session scan A 22637b90cebd

Subscribe to this mod's changes

author-migration is a skill published in the GitHub repository nrwl/nx (29,304 stars, last pushed today), licensed MIT. It adds 176 tokens to every session and 10,204 once invoked, about $0.0009 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.