Schema Validator Connector

What this connector is for

Validates a JSON value against a JSON Schema, and — unlike most connectors — stops the workflow with a configurable HTTP-style error response when validation fails, so you don't need a separate branch/condition step to check a boolean and halt manually. Complements Mapper (which validates too, but only fields it just reshaped) and JSONata (which transforms but never validates).

Validation runs on AJV with format support (ajv-formats) enabled, using AJV's Draft 7 compiler. A $schema field in your schema is stripped before compiling (it's metadata AJV doesn't need to compile against) — most Draft 2020-12 schemas validate correctly under this setup, but draft-specific keywords not supported by AJV 8's default dialect aren't guaranteed to work.

Validate Schema

Configuring it

• Data to Validate — required. The value to validate — usually a template reference like {{trigger.body}} or {{someStep.response.data}}. If it's a string, it's parsed as JSON first; if parsing fails, the raw string is validated as-is (so a schema of {"type": "string"} still works against non-JSON input).
• JSON Schema — required. The schema itself, JSON Schema Draft 7 or later, as a JSON string.
• Error Response Configuration — optional; if omitted, a default error response is used.
  • HTTP Status Code — default 400. Must be 100–599.
  • Error Response Body — a string. If it contains the literal {{errors}}, that's replaced with the JSON-stringified validation error array before the body is (attempted to be) parsed as JSON; otherwise the whole body is parsed as JSON if possible, or used as a literal string if not.
  • Error Response Headers — key/value pairs; Content-Type: application/json is always added regardless of what you set here.

Reading the response

The shape differs by outcome:

• Validation passed — a plain result, nested under the action envelope:
  • {{<stepReference>.response.data.validated}} — true.
  • {{<stepReference>.response.data.data}} — the validated data (JSON-parsed, if the input was a JSON string).
• Validation failed (or an unexpected error during validation) — an HTTP-style result, spread flat:
  • {{<stepReference>.response.status}} — the configured (or default 400) status code.
  • {{<stepReference>.response.data}} — the error response body.
  • {{<stepReference>.response.validationErrors}} — array of {path, message, schemaPath}, a sibling of status/data here, not nested under data.

For example, a step named "Validate Order" (reference validateOrder) — on success, {{validateOrder.response.data.validated}} is true; on failure, check {{validateOrder.response.status}} to branch, and {{validateOrder.response.validationErrors}} for the specific field(s) that failed.

Example

Data to Validate: {{trigger.body}}
JSON Schema:
{
  "type": "object",
  "properties": {
    "name": {"type": "string"},
    "age": {"type": "number", "minimum": 0}
  },
  "required": ["name", "age"]
}

A trigger body of {"name": "Ada"} (missing age) halts the workflow with {{validateOrder.response.status}} = 400 and {{validateOrder.response.validationErrors}} reporting the missing required field.