/cobol-modernization

name: cobol-modernization
description: End-to-end COBOL to Java migration workflow. Handles build setup, mainframe dependency removal, and code migration with test validation.
license: MIT
compatibility: Requires GnuCOBOL, Java 11+, Maven/Gradle, Python 3.13 with uv
triggers:
  - cobol modernization
  - cobol to java
  - cobol migration
  - mainframe migration

End-to-end workflow for migrating COBOL codebases to Java.

Overview

This plugin orchestrates a multi-phase COBOL modernization project:

1. **Build Setup** — Configure compilation for both COBOL and Java, create test fixtures 2. **Mainframe Planning** — Document transformations needed to remove mainframe dependencies 3. **Mainframe Removal** — Convert CICS/VSAM code to standard COBOL 4. **Java Migration** — Translate standardized COBOL to idiomatic Java

Prerequisites

• GnuCOBOL compiler (`cobc`)
• Java 11+ with Maven or Gradle
• Python 3.13 with `uv`
• LLM API key (Anthropic or OpenAI)

Quick Start

export LLM_API_KEY="your-api-key"
export LLM_MODEL="anthropic/claude-3-5-sonnet-20241022"

uv run python -m lc_sdk_examples.cobol_modernization --src-path /path/to/cobol/project

PowerShell equivalent for the environment setup:

$env:LLM_API_KEY = "your-api-key"
$env:LLM_MODEL = "anthropic/claude-3-5-sonnet-20241022"

uv run python -m lc_sdk_examples.cobol_modernization --src-path C:\path\to\cobol\project

Workflow Phases

Phase 1: Build Setup

See [../build-setup/SKILL.md](../build-setup/SKILL.md)

Creates the foundation for the migration:

• COBOL compilation environment (GnuCOBOL)
• Java project structure (Maven/Gradle + JUnit 5)
• Test fixtures with golden outputs from COBOL execution

**Outputs:**

• `build_notes.md` — Build instructions
• `test-fixtures/` — Input/output test data
• `test_manifest.json` — Test case mapping

Phase 2: Mainframe Planning

See [../mainframe-planning/SKILL.md](../mainframe-planning/SKILL.md)

Creates a transformation guide without modifying code:

• Maps CICS/VSAM constructs to standard COBOL equivalents
• Documents error handling replacements
• Identifies UI operations to stub

**Output:**

• `mainframe_dependency_removal_plan.md`

Phase 3: Mainframe Removal

See [../mainframe-removal/SKILL.md](../mainframe-removal/SKILL.md)

Applies the transformation guide:

• Replaces EXEC CICS commands with file I/O
• Adds FILE STATUS checking
• Stubs BMS/screen operations

**Verification:**

• Code compiles with GnuCOBOL
• Runs with test fixtures

Phase 4: Java Migration

See [../to-java-migration/SKILL.md](../to-java-migration/SKILL.md)

Translates to idiomatic Java:

• Proper Java conventions (not literal translations)
• JUnit tests using golden outputs
• COBOL references in comments

**Done when:**

• All code compiles
• All JUnit tests pass
• No TODOs or stubs remain

Output Structure

your-project/
├── .lc-sdk/
│   ├── initial_batch_graph.json
│   ├── fixed_batch_graph.json
│   └── mainframe_dependency_removal_plan.md
├── test-fixtures/
│   ├── inputs/
│   └── expected_outputs/
├── test_manifest.json
├── src/main/java/
└── src/test/java/

Troubleshooting

See [../../references/troubleshooting.md](../../references/troubleshooting.md) for common issues and solutions.