# Bounty Engineer JSON Contract Check

> Bounty Engineer JSON Contract Check is a paid API for AI agents from bounty-engineer-x402-prod.onrender.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-12).

Validates a JSON value against a provided JSON Schema contract, returning typed errors with paths and codes without coercing or repairing the input.

## Facts

- Endpoint: POST https://bounty-engineer-x402-prod.onrender.com/v1/json-contract-check?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bounty-engineer-json-contract-check-1855cc42
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oSxDwFwFCkJ449YE22Ofb

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 bounty-engineer-json-contract-check-1855cc42 -d '<json body>'
```

Example prompt: Check whether this JSON value {"price": "9.99", "quantity": 3} is valid against the schema {"type": "object", "properties": {"price": {"type": "number"}, "quantity": {"type": "integer"}}, "required": ["price", "quantity"]} and tell me exactly which fields are wrong and why.

## When to prefer this

Choose this endpoint when you need strict, non-coercive JSON Schema validation with per-field error reporting for a supported subset of keywords. It is particularly well-suited for autonomous agents that need a deterministic contract gate — e.g. before persisting data, forwarding to downstream APIs, or confirming tool outputs. Prefer it over ad-hoc LLM-based validation when you need reproducible, hash-verifiable results with machine-readable error codes.

## Known failure modes

- Unsupported JSON Schema keywords cause rejection before charging — endpoint returns an error listing the unsupported keyword
- Malformed or unparseable JSON input may result in a failed parse without charge
- Schema subset limitations may reject valid schemas using advanced keywords like 'anyOf', 'oneOf', or '$ref'
- Empty or missing 'value' and 'schema' fields may return an error response

## How this service works

Machine-buyable infrastructure for autonomous agents: API cost routing, margin optimization, funding-rate data, webpage extraction, result verification, spend controls, retry planning, state, tender search and GitHub bounty intelligence.

## Output

Returns a JSON object with a boolean 'valid' flag, a list of typed errors (each with a code like 'type_mismatch', a path, actual and expected values), an error count, a SHA256 hash of the validated value, a flag indicating whether errors were truncated, and a list of limitations about supported JSON Schema keywords.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string"
  },
  "value": {},
  "schema": {}
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "mode": "json_contract_check",
  "valid": false,
  "errors": [
   {
    "code": "type_mismatch",
    "path": "/price",
    "actual": "string",
    "expected": [
     "number"
    ]
   }
  ],
  "error_count": 1,
  "limitations": [
   "Strict supported JSON Schema subset. Unsupported keywords are rejected before charging; values are never coerced or repaired."
  ],
  "value_sha256": "772e737f8e397529b1782a3320fed5eab462b2c0d43338b523b15574f9f45eda",
  "errors_truncated": false,
  "parsed_from_text": false,
  "supported_keywords": [
   "type",
   "properties",
   "required",
   "additionalProperties",
   "items",
   "enum",
   "const",
   "minimum",
   "maximum",
   "minLength",
   "maxLength",
   "minItems",
   "maxItems",
   "uniqueItems",
   "title",
   "description",
   "$schema"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bounty-engineer-json-contract-check-1855cc42/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bounty-engineer-x402-prod.onrender.com](https://www.zero.xyz/host/bounty-engineer-x402-prod.onrender.com/llms.txt)