---
name: legacy-code-interpreter-ed44d12cc737
description: Understand and document legacy code behavior through deep analysis and behavior characterization
allowed-tools: ["Bash", "Read", "Write", "Grep", "Glob", "Edit"]
graph:
  domains: [domain:software-engineering]
  specializations: [specialization:code-migration-modernization]
  skillAreas: [skill-area:code-analysis-linting, skill-area:dead-code-elimination]
  roles: [role:backend-engineer, role:architect]
  workflows: [workflow:technical-debt-reduction]
  topics: [topic:refactoring]
---

# Legacy Code Interpreter Skill

Deep analysis and interpretation of legacy code to understand undocumented behavior, extract business logic, and characterize system functionality.

## Purpose

Enable legacy code understanding for:
- Business logic extraction
- Undocumented feature discovery
- Behavior characterization
- Migration planning
- Knowledge preservation

## Capabilities

### 1. Business Logic Extraction
- Parse conditional logic
- Extract calculation formulas
- Identify validation rules
- Document decision trees

### 2. Undocumented Feature Discovery
- Find hidden functionality
- Identify feature flags
- Discover Easter eggs
- Map admin features

### 3. Control Flow Analysis
- Trace execution paths
- Map state machines
- Identify loops and recursion
- Document entry points

### 4. Data Flow Tracking
- Trace data transformations
- Map input to output
- Identify side effects
- Document state changes

### 5. Side Effect Identification
- Find external calls
- Identify I/O operations
- Map database operations
- Document messaging

### 6. Behavior Characterization
- Create behavior summaries
- Generate pseudo-code
- Document edge cases
- Map error handling

## Tool Integrations

| Tool | Purpose | Integration Method |
|------|---------|-------------------|
| Understand (SciTools) | Deep analysis | CLI / API |
| Lattix | Architecture analysis | CLI |
| CodeScene | Behavioral analysis | API |
| Sourcetrail | Code exploration | CLI |
| ast-grep | Pattern matching | MCP / CLI |

## Output Schema

```json
{
  "analysisId": "string",
  "timestamp": "ISO8601",
  "interpretation": {
    "businessLogic": [
      {
        "name": "string",
        "location": "string",
        "description": "string",
        "pseudoCode": "string",
        "inputs": [],
        "outputs": [],
        "sideEffects": []
      }
    ],
    "controlFlow": {
      "entryPoints": [],
      "stateMachines": [],
      "criticalPaths": []
    },
    "dataFlow": {
      "transformations": [],
      "stateChanges": []
    },
    "undocumented": []
  }
}
```

## Integration with Migration Processes

- **legacy-codebase-assessment**: Primary interpretation tool
- **migration-planning-roadmap**: Knowledge source

## Related Skills

- `static-code-analyzer`: Structural analysis
- `knowledge-extractor`: Documentation mining

## Related Agents

- `legacy-system-archaeologist`: Uses for excavation


---
Source attribution: a5c-ai
Original project: https://github.com/a5c-ai/babysitter
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Gabriel Moreira

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: a5c-ai
Original project: https://github.com/a5c-ai/babysitter
Attribution basis: Upstream repository explicitly recorded in package mirror path

Fields of work: Data & Analytics, Development & Engineering, Operations, Product Management
Roles: Backend Developer, Business Process Analyst, Data Analyst, Product Manager, Technical Product Manager
Specialties: Backend
Tools: Codescene, Lattix, Sourcetrail, Ast Grep, Understand (Scitools)
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 83e525e03cb58aca431b0dba8945432a402b58b56e0d0337d4b243deff4d4173