Validate JSON against a JSON Schema
Validate JSON against a JSON Schema. Checks LLM and agent output and API request payloads, returning structured errors with error codes, JSONPath locations, and a plain-English summary. Optional automatic repair of invalid payloads.
Answeringour last check, 2026-10-11
1 of 1checks answered this week
1356 msmedian answer time
$0.002listed price per call
$0.002price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://projectx402-production.up.railway.app/v1/schema-check
| Category | Code and developer |
|---|---|
| Provider host | projectx402-production.up.railway.app |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-11 | valid payment request | 402 | $0.002 | 1356 ms |
Example input (from the provider)
{
"body": {
"explain": true,
"json_schema": {
"properties": {
"age": {
"type": "integer"
},
"name": {
"type": "string"
}
},
"required": [
"name",
"age"
],
"type": "object"
},
"payload": {
"age": 30,
"name": "Alice"
},
"repair": false,
"strictness": "normal"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"explain": {
"description": "If true, include a plain-English summary. Default: true",
"type": "boolean"
},
"json_schema": {
"description": "JSON Schema document to validate the payload against",
"type": "object"
},
"payload": {
"description": "The JSON value to validate against the schema"
},
"repair": {
"description": "If true, return a suggested corrected payload. Default: false",
"type": "boolean"
},
"strictness": {
"description": "Validation strictness. Default: normal",
"enum": [
"strict",
"normal",
"lenient"
],
"type": "string"
}
},
"required": [
"json_schema",
"payload"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}