LLM Structured Output Validator
Supported Validations
What This Tool Does
LLM Structured Output Validator is built for deterministic developer and agent workflows.
Validate LLM structured outputs against JSON Schema draft-07. Presets for OpenAI, Anthropic, and MCP formats with detailed error reporting.
Use How to Use for execution steps and FAQ for constraints, policies, and edge cases.
Last updated:
This tool is provided as-is for convenience. Output should be verified before use in any production or critical context.
Agent Invocation
Best Path For Builders
Dedicated API endpoint
Deterministic outputs, machine-safe contracts, and production-ready examples.
Dedicated API
https://aidevhub.io/api/schema-validator/ OpenAPI: https://aidevhub.io/api/openapi.yaml
Unified Runtime API
https://aidevhub.io/api/tools/run/?toolId=structured-output-validator&a=...
GET and POST are supported at /api/tools/run/ with identical validation and limits.
Limit: req / s, input max 256 KB.
REST API
Base URL
https://aidevhub.io/api/schema-validator/ 50 requests/day per IP. No authentication required. CORS enabled. OpenAPI spec
Endpoints
Example
curl -X POST https://aidevhub.io/api/schema-validator/ -H "Content-Type: application/json" -d '{"schema": "{\"type\": \"object\"}", "target": "openai"}' Example Response
{
"valid": true,
"errors": [],
"warnings": [],
"fixed_schema": null
} How to Use LLM Structured Output Validator
- 1
Define JSON Schema
Paste your JSON Schema or select from templates (object with properties, array of records, etc.). The tool validates the schema itself.
- 2
Paste LLM output
Copy the structured response from your LLM (Claude, GPT, etc.) into the validation panel. Format can be JSON, YAML, or markdown code block.
- 3
Validate against schema
Click 'Validate' to check if the output matches the schema. Shows specific field violations (type mismatch, missing required fields, enum mismatches).
- 4
Debug errors
The tool highlights which fields failed validation and why. Suggests corrections for common issues like wrong data types or invalid enums.
- 5
Fix and retry
Edit the JSON inline and re-validate. Once passing, export as TypeScript types or use in your application code.