# LLM Output Validator

> LLM Output Validator is a paid API for AI agents from llm-output-validator.johntaylor1online.workers.dev, paid per call via x402, $0.5/call, status unknown (last checked 2026-10-14).

Validates LLM-generated outputs via a POST endpoint, checking for quality, correctness, or schema conformance

## Facts

- Endpoint: POST https://llm-output-validator.johntaylor1online.workers.dev/validate?utm_source=zero.xyz
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/llm-output-validator-c61b1cd3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_w2U7z9Kin2ML3TGQZDRQH

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability llm-output-validator-c61b1cd3 -d '<json body>'
```

Example prompt: Can you validate this LLM output to make sure it's correct and well-formed — here's the original input and the AI-generated response I want to check?

## When to prefer this

Choose this endpoint when you need to programmatically validate or quality-check LLM-generated outputs before using them downstream, especially in agentic pipelines where unchecked AI responses could cause errors or propagate hallucinations. Useful as a gate between LLM generation and action execution.

## Known failure modes

- Missing required 'input' or 'output' fields returns a 400 error
- Malformed JSON body causes request rejection
- Invalid HTTP method (non-POST) returns method not allowed
- Payment not included or insufficient USDC results in 402 Payment Required
- Large or complex outputs may time out or fail validation

## How this service works

LLM Output Validator

## Output

Returns a validation result object indicating whether the LLM output is valid, along with any errors, issues, or conformance details found during the check.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/llm-output-validator-c61b1cd3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from llm-output-validator.johntaylor1online.workers.dev](https://www.zero.xyz/host/llm-output-validator.johntaylor1online.workers.dev/llms.txt)