code-migration

A six-step process for moving a codebase from one programming language to another while checking that its behavior stays the same.

In plain words
What is it for?
Use it to migrate, port, or rewrite a codebase, such as moving a Python command-line tool to Rust.
Why use it?
Large migrations can introduce subtle differences; the process maps the code, tests the translation rules, compiles the result, runs it, and compares behavior.

Skill for Claude CodeCodex

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/anthropics/code-migration-kit-with-claude-code/skill
Any agent
npx skills add anthropics/code-migration-kit-with-claude-code --skill skill
Clone the repo
git clone --depth 1 https://github.com/anthropics/code-migration-kit-with-claude-code

Made for: Claude Code, Codex.

Per session 110 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 976 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00110 $0.00976
Opus 5 $0.00055 $0.00488
Sonnet 5 $0.00022 $0.00195
Haiku 4.5 $0.00011 $0.00098

Measured 2d ago against content hash a4da0cbbdf4d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

code-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 2d 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.

skill/SKILL.md · 70 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 2d ago First seen · 70 lines · 110 tokens per session scan A a4da0cbbdf4d

Subscribe to this mod's changes

code-migration is a skill published in the GitHub repository anthropics/code-migration-kit-with-claude-code (323 stars, last pushed 1mo ago), with no licence file. It adds 110 tokens to every session and 976 once invoked, about $0.0006 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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