What is rpg-migration-analyzer?

An analysis tool for RPG, or Report Program Generator, programs running on IBM AS/400 and IBM i business systems. It identifies their business rules, data structures, file operations, and program dependencies to support a move to Java.

Use it to examine RPG source files, map RPG data and file operations to Java and database patterns, trace program call chains, and prepare Java code structures.

It helps teams understand older RPG systems before replacing them, reducing the risk of losing important business behavior during migration.

rpg-migration-analyzer — Skill for Claude Code and Codex by DauQuangTh

Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo

git clone --depth 1 https://github.com/DauQuangThanh/hanoi-rainbow

agentmods

npx agentmods add skills/dauquangthanh/hanoi-rainbow/rpg-migration-analyzer

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/dauquangthanh/hanoi-rainbow/rpg-migration-analyzer/github.svg)](https://agentmods.dev/skills/dauquangthanh/hanoi-rainbow/rpg-migration-analyzer)

Your own site

<a href="https://agentmods.dev/skills/dauquangthanh/hanoi-rainbow/rpg-migration-analyzer"><img src="https://agentmods.dev/badge/skills/dauquangthanh/hanoi-rainbow/rpg-migration-analyzer/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/dauquangthanh/hanoi-rainbow/rpg-migration-analyzer"><img src="https://agentmods.dev/badge/skills/dauquangthanh/hanoi-rainbow/rpg-migration-analyzer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 186 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,282 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 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.

Model	Per session	Once invoked
Fable 5.1	$0.00186	$0.04282
Opus 5	$0.00093	$0.02141
Sonnet 5	$0.00037	$0.00856
Haiku 4.5	$0.00019	$0.00428

Measured 10d ago against content hash f2dbf8fa552a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

rpg-migration-analyzer 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 10d ago.

The scan reads SKILL.md. This mod also ships 5 executable files (scripts/analyze-dependencies.ps1, scripts/analyze-dependencies.sh, scripts/estimate-complexity.py, …), 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.

skills/rpg-migration-analyzer/SKILL.md · 427 lines

How it starts

The opening of the file, as written. The whole thing — 427 lines — stays where its author put it; the contents beside it link to each section on GitHub.

RPG Migration Analyzer

Analyzes legacy RPG programs (RPG III/IV/ILE) from AS/400 and IBM i systems for migration to modern Java applications, extracting business logic, data structures, file operations, and generating actionable migration strategies.

Overview

This skill provides comprehensive analysis and migration planning for RPG (Report Program Generator) applications. It extracts program specifications, converts RPG data types to Java equivalents, maps file operations to modern database access patterns, and generates implementation-ready Java code structures.

Key Migration Focus: RPG to Java with proper handling of packed decimals (BigDecimal), data structures (POJOs), file operations (JPA/JDBC), indicators (boolean variables), and business logic preservation.

When to Use This Skill

Use this skill when:

Analyzing RPG source files (.rpg, .rpgle, .RPGLE) for modernization
Planning migration from AS/400 or IBM i systems to Java
Converting RPG data structures (D-specs) to Java classes
Mapping RPG file operations (F-specs) to database access patterns
Understanding RPG program dependencies and call chains
Generating Java code equivalents from RPG business logic
Estimating complexity and effort for RPG migration projects
Creating migration documentation and strategy reports
Modernizing legacy mainframe applications to microservices
User mentions: RPG analysis, AS/400 migration, IBM i modernization, Report Program Generator, packed decimal conversion

Core Capabilities

1. Program Analysis

Extract and analyze RPG program components:

Specification types: H-spec (header/control), F-spec (file definitions), D-spec (data definitions), C-spec (calculation/logic), P-spec (procedures)
Data structures: D-specs with nested structures, arrays (DIM), external references (EXTNAME), qualifiers (LIKEDS, QUALIFIED)
File definitions: Physical files, logical files, display files (WORKSTN), printer files
Business logic: Calculation specifications, control structures (IF/ELSE/DO/FOR), expressions (EVAL)
Indicators: Legacy indicators (*IN01-*IN99), built-in indicators (*INLR,*INOF)
Built-in functions: String functions (%SUBST, %TRIM, %SCAN), date functions (%DATE, %DAYS), math functions (%DEC, %INT), file status (%EOF, %FOUND, %ERROR)
Error handling: %ERROR, %STATUS, ON-ERROR blocks

Read the full file on GitHub · 427 lines

Files

What ships with it

20 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.

10d ago First seen · 427 lines · 186 tokens per session scan A f2dbf8fa552a

Subscribe to this mod's changes

rpg-migration-analyzer is a skill published in the GitHub repository DauQuangThanh/hanoi-rainbow (16 stars, last pushed 7mo ago), licensed MIT. It adds 186 tokens to every session and 4,282 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 2026-08-31.

Java Languages agentic-ai ai process software-development spec-driven spec-driven-development

agentscope-java

Expert Java developer skill for AgentScope Java framework - a reactive, message-driven multi-agent system built on Project Reactor. Use when working with reactive programming, LLM integration, agent orchestration, multi-agent systems, or when the user mentions AgentScope, ReActAgent, Mono/Flux, Project Reactor, or…

agentscope-ai/agentscope-java · 91 tokens

java-regression-test-generator

Automatically generate regression tests for Java codebases by analyzing changes between old and new code versions. Use when users need to: (1) Generate tests after refactoring or code changes, (2) Ensure previously tested behavior still works in new versions, (3) Cover modified or newly added code paths, (4) Migrate…

ArabelaTso/Skills-4-SE · 111 tokens

incremental-java-programmer

Incrementally implement new features in Java repositories from natural language descriptions. Use when adding functionality to existing Java codebases (Maven or Gradle projects). Takes a feature description as input and outputs modified repository with implementation code, corresponding JUnit tests, and verification…

ArabelaTso/Skills-4-SE · 78 tokens

pseudocode-to-java-code

Converts pseudocode descriptions and algorithm specifications into complete, executable Java code. Use this skill when you need to implement algorithms from pseudocode, translate algorithm descriptions to Java, generate Java code from specifications, convert textbook algorithms to working code, or create executable…

ArabelaTso/Skills-4-SE · 85 tokens

spring-mvc-to-boot-migrator

Automatically migrate Spring MVC applications to Spring Boot. Use when you need to modernize a Spring MVC project to Spring Boot while preserving functionality. The skill analyzes the codebase, updates build configuration (Maven/Gradle), migrates annotations, converts XML configuration to Java/properties, updates…

ArabelaTso/Skills-4-SE · 101 tokens

java

Use when writing, reviewing or refactoring modern Java (21+, 25 LTS) — records and sealed interfaces as algebraic data types, exhaustive pattern-matching switch over instanceof ladders, virtual-thread concurrency, structured concurrency and ScopedValue replacing ThreadLocal, Stream and Optional pipelines…

ericrisco/rsc-harness · 89 tokens