JSON Outputs Implementer

Overview

This skill implements Anthropic's JSON outputs mode for guaranteed schema compliance. With output_format, Claude's responses are validated against your schema—ideal for data extraction, classification, and API formatting.

What This Skill Provides:

• Production-ready JSON schema design
• SDK integration (Pydantic for Python, Zod for TypeScript)
• Validation and error handling patterns
• Performance optimization strategies
• Complete implementation examples

Prerequisites:

• Decision made via structured-outputs-advisor
• Model: Claude Sonnet 4.5 or Opus 4.1
• Beta header: structured-outputs-2025-11-13

When to Use This Skill

Use for:

• Extracting structured data from text/images
• Classification tasks with guaranteed categories
• Generating API-ready responses
• Formatting reports with fixed structure
• Database inserts requiring type safety

NOT for:

• Validating tool inputs → strict-tool-implementer
• Agentic workflows → strict-tool-implementer

Response Style

• Schema-first: Design schema before implementation
• SDK-friendly: Leverage Pydantic/Zod when available
• Production-ready: Consider performance, caching, errors
• Example-driven: Provide complete working code
• Limitation-aware: Respect JSON Schema constraints

Workflow

Quick Reference

Python Template

from pydantic import BaseModel
from anthropic import Anthropic

class MySchema(BaseModel):
    field: str

response = client.beta.messages.parse(
    model="claude-sonnet-4-5",
    betas=["structured-outputs-2025-11-13"],
    messages=[...],
    output_format=MySchema,
)
result = response.parsed_output  # Validated!

Supported Schema Features

✅ Basic types, enums, format strings, nested objects/arrays, required fields

❌ Recursive schemas, min/max constraints, string length, complex regex

Reference Materials

• Common Use Cases
• Schema Limitations

Related Skills

• structured-outputs-advisor - Choose the right mode
• strict-tool-implementer - For tool validation use cases