# Agent Payload Tools – JSON Validate

> Agent Payload Tools – JSON Validate is a paid API for AI agents from api.agent-payload-tools.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Validates a JSON value against a compact schema definition and returns whether the value conforms

## Facts

- Endpoint: POST https://api.agent-payload-tools.workers.dev/json-validate
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-payload-tools-json-validate-f1afb158
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_urgF6NKbZWti4bjD9Dnc_

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 agent-payload-tools-json-validate-f1afb158 -d '<json body>'
```

Example prompt: Can you validate this JSON object against my schema — the value is {"name":"Alice","age":30} and the schema requires name to be a string and age to be an integer?

## When to prefer this

Choose this endpoint when you need a deterministic, schema-driven JSON validation step inside an AI agent pipeline without standing up your own validation infrastructure. Particularly useful when you want to guard against malformed tool outputs or user-submitted payloads before passing them to downstream services, and you are already operating in the x402 micropayment ecosystem on Base or Solana.

## Known failure modes

- Malformed JSON value causes a parse error
- Schema definition uses unsupported keywords and is rejected
- Missing required fields in the request body returns a 400 error
- Value is valid JSON but schema is not an object, causing schema parse failure
- Payment not included or insufficient USDC causes a 402 response

## How this service works

Validate a JSON value against the supported compact schema subset.

## Output

Returns whether the provided JSON value conforms to the supplied compact validation schema, along with any validation errors or constraint violations identified.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "value": {
   "description": "JSON value to validate."
  },
  "schema": {
   "type": "object",
   "description": "Supported compact validation schema.",
   "propertyNames": {
    "type": "string"
   },
   "additionalProperties": {}
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-payload-tools-json-validate-f1afb158/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.agent-payload-tools.workers.dev](https://www.zero.xyz/host/api.agent-payload-tools.workers.dev/llms.txt)