JSON Schema Validation

Validate incoming webhook payloads against a JSON schema to ensure data structure compliance.

Configuration

{
    "validated_webhook": {
        "data_type": "json",
        "module": "log",
        "authorization": "Bearer token",
        "json_schema": {
            "type": "object",
            "properties": {
                "event": {"type": "string"},
                "data": {
                    "type": "object",
                    "properties": {
                        "id": {"type": "integer"},
                        "name": {"type": "string"}
                    },
                    "required": ["id", "name"]
                }
            },
            "required": ["event", "data"]
        }
    }
}

Schema Format

The json_schema field accepts a standard JSON Schema (Draft 7) definition:

• type: Data type (object, array, string, number, boolean, null)
• properties: Object properties definition
• required: Array of required property names
• items: Schema for array items
• additionalProperties: Whether to allow additional properties

Example Schemas

Simple Object

{
    "json_schema": {
        "type": "object",
        "properties": {
            "event": {"type": "string"},
            "timestamp": {"type": "number"}
        },
        "required": ["event"]
    }
}

Nested Object

{
    "json_schema": {
        "type": "object",
        "properties": {
            "user": {
                "type": "object",
                "properties": {
                    "id": {"type": "integer"},
                    "email": {"type": "string", "format": "email"}
                },
                "required": ["id", "email"]
            }
        },
        "required": ["user"]
    }
}

Array Validation

{
    "json_schema": {
        "type": "object",
        "properties": {
            "items": {
                "type": "array",
                "items": {
                    "type": "string"
                },
                "minItems": 1,
                "maxItems": 100
            }
        }
    }
}

Error Response

When validation fails:

{
    "error": "JSON schema validation failed",
    "detail": "Validation error details..."
}

HTTP Status: 400 Bad Request

Features

• Standard JSON Schema (Draft 7) support
• Nested object validation
• Array validation
• Type checking
• Required field validation
• Clear error messages
• SSRF protection (blocks remote schema references)

Security

SSRF Protection

Remote schema references ($ref with URLs) are blocked to prevent Server-Side Request Forgery attacks:

// This will be blocked - remote $ref not allowed
{
    "json_schema": {
        "$ref": "https://malicious.com/schema.json"
    }
}

Only local/inline schema definitions are supported. If you need to reuse schemas, define them inline using definitions:

{
    "json_schema": {
        "definitions": {
            "address": {
                "type": "object",
                "properties": {
                    "street": {"type": "string"},
                    "city": {"type": "string"}
                }
            }
        },
        "type": "object",
        "properties": {
            "shipping_address": {"$ref": "#/definitions/address"},
            "billing_address": {"$ref": "#/definitions/address"}
        }
    }
}