java-kotlin-migration-assistant

java-kotlin-migration-assistant is a skill for Claude Code, Codex from JetBrains/skills. It costs 77 tokens per session (1,361 once invoked), scanned A, original, no licence file.

Guidance for gradually converting Java code to Kotlin in Spring applications while preserving how the existing code behaves and connects to other code.

In plain words
What is it for?
Use it to migrate classes incrementally, replace Lombok patterns, and review compatibility with Spring, JPA, runtime proxies, and existing compiled code.
Why use it?
It helps avoid accidental changes to public interfaces, framework behavior, database entities, generated-code patterns, and Kotlin's handling of nullable values.

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/jetbrains/skills/java-kotlin-migration-assistant
Any agent
npx skills add JetBrains/skills --skill java-kotlin-migration-assistant
Clone the repo
git clone --depth 1 https://github.com/JetBrains/skills

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 java-kotlin-migration-assistant

README.md
[![agentmods](https://agentmods.dev/badge/skills/jetbrains/skills/java-kotlin-migration-assistant.svg)](https://agentmods.dev/skills/jetbrains/skills/java-kotlin-migration-assistant)
Your own site
<a href="https://agentmods.dev/skills/jetbrains/skills/java-kotlin-migration-assistant"><img src="https://agentmods.dev/badge/skills/jetbrains/skills/java-kotlin-migration-assistant.svg" alt="Measured on agentmods" height="20"></a>
Per session 77 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,361 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 $0.00077 $0.01361
Opus 5 $0.00039 $0.00681
Sonnet 5 $0.00015 $0.00272
Haiku 4.5 $0.00008 $0.00136

Measured 5d ago against content hash 4048cae1445b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

java-kotlin-migration-assistant 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.

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.

java-kotlin-migration-assistant/SKILL.md · 117 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

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. 5d ago First seen · 117 lines · 77 tokens per session scan A 4048cae1445b

Subscribe to this mod's changes

java-kotlin-migration-assistant is a skill published in the GitHub repository JetBrains/skills (335 stars, last pushed 2mo ago), with no licence file. It adds 77 tokens to every session and 1,361 once invoked, about $0.0004 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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