# Prompt Engineering 6 Structured Output

> Sub-skill of prompt-engineering: 6. Structured Output (+2).

- Skill: `vamseeachanta/prompt-engineering-6-structured-output` (Agent Skill)
- Install (CLI): `npx skillmds@latest add vamseeachanta/prompt-engineering-6-structured-output`
- Raw SKILL.md: https://api.skillmd.com/api/skills/vamseeachanta/prompt-engineering-6-structured-output/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: vamseeachanta (https://skillmd.com/u/vamseeachanta)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/vamseeachanta/prompt-engineering-6-structured-output

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# 6. Structured Output (+2)

## 6. Structured Output


**JSON Output:**
```python
JSON_OUTPUT_TEMPLATE = """
Analyze the following engineering data and return your analysis as JSON.

Data:
{input_data}

Return a JSON object with this exact structure:
{{

*See sub-skills for full details.*

## 7. Prompt Templates


**Reusable Template Class:**
```python
from string import Template
from typing import Dict, Any, Optional
import json

class PromptTemplate:
    """
    Reusable prompt template with validation and versioning.
    """

*See sub-skills for full details.*

## 8. Evaluation and Iteration


**Prompt Testing Framework:**
```python
from dataclasses import dataclass
from typing import Callable, List
import json

@dataclass
class TestCase:
    """Single test case for prompt evaluation."""
    input_data: dict

*See sub-skills for full details.*