MongoDB Migration Assistant

AI-powered TUI tool for MongoDB schema diffing and migration script generation.

Built with Java 17 + JLine 3 + Anthropic Claude SDK.

Features

• Schema Diff — Compare two MongoDB document schemas (JSON files or pasted JSON)
• Smart Detection — Identifies added, removed, renamed fields, type changes, and structural changes
• AI Script Generation — Uses Claude API to generate production-ready mongosh migration scripts
• Fallback Mode — Generates template scripts even without an API key
• Type Inference — Detects strings that should be Dates, Decimals, ObjectIds, Integers
• Rollback Scripts — Every migration includes a reverse/rollback section
• Sample Data — Built-in insurance domain sample for quick demo

Prerequisites

• Java 17+
• Maven 3.8+
• (Optional) Anthropic API key for AI-powered script generation

Quick Start

# Clone / navigate to project
cd MongoSchemaMigrationAssistant

# Build
mvn clean package -q

# Set API key (optional, enables AI mode)
export ANTHROPIC_API_KEY=sk-ant-api03-...

# Run
java -jar target/mongo-migration-assistant-0.1.0-SNAPSHOT.jar

# Or run via Maven
mvn exec:java -q

Usage

1. Schema Diff from Files

Prepare two JSON files representing your MongoDB documents:

source.json (current schema):

{
  "name": "John Doe",
  "premium": "1250.50",
  "createdAt": "2024-01-15T00:00:00Z"
}

target.json (desired schema):

{
  "fullName": "John Doe",
  "premium": 1250.50,
  "createdAt": "2024-01-15T00:00:00Z",
  "updatedAt": ""
}

Launch the app, select option 1, enter file paths, and run the diff.

2. Paste JSON Directly

Select "Paste JSON" to enter schemas directly in the TUI.

3. Try the Sample

Select "Use Sample" to see a full insurance domain migration example.

Architecture

dev.mongomigrate/
├── App.java                 # Entry point
├── tui/
│   └── TuiManager.java      # JLine TUI screens & navigation
├── core/
│   ├── SchemaDiffer.java     # Schema comparison engine
│   ├── DiffEntry.java        # Single diff item model
│   └── DiffResult.java       # Complete diff result
├── ai/
│   └── ClaudeService.java    # Anthropic SDK integration
└── model/
    └── MigrationContext.java  # Shared state between screens

Roadmap

• Direct MongoDB connection for live schema introspection
• Batch processing with progress bars for large collections
• Dry-run mode (apply to N sample docs and show results)
• Config file support (~/.mongomigrate.yaml)
• Export diff as HTML report
• Multi-collection migration workflows
• Index diff and migration
• Integration with mongosh for direct execution

License

MIT