Data requirements — QuantaAPI docs

Data requirements turn a mock into a contract. Open the Data requirement tab to require headers and body fields; requests that do not comply are rejected with 400 before the response is rendered.

Header requirement

Headers are always strings. You can only require a header and constrain its length.

NAME	TYPE	REQUIRED	DESCRIPTION
Name	string	Yes	Header name. Matching is case-insensitive.
Type	string	Fixed	Always `string` for headers.
Min Characters	number	No	Minimum accepted length.
Max Characters	number	No	Maximum accepted length.

Body requirement

NAME	TYPE	REQUIRED	DESCRIPTION
Name	string	Yes	Top-level body field. Matching is case-insensitive.
Type	string \| number	Yes	`string` checks length; `number` checks value range.
Min / Max Characters	number	For string	Minimum and maximum accepted length.
Min / Max Value	number	For number	Minimum and maximum accepted value.

Top-level fields onlyValidation inspects top-level keys of the body object. Nested objects are not enforced.

How validation runs

The body is read as raw text and parsed as JSON. A body that is not valid JSON is reported as an error.
Only fields declared in the data requirement are checked. Extra fields in the request are allowed.
Names are compared case-insensitively, so X-Tenant and x-tenant are the same header.
A missing field or a value outside its rule adds an entry to the error list.

For GET, HEAD, DELETE, OPTIONS, and other methods without a request body, body rules are skipped entirely and only headers are validated.

What a failed validation returns

The status is 400. The JSON body is your response template rendered with the validation message, and the details are sent in the X-Validation-Errors header as a JSON array.

X-Validation-Errors

[
  {
    "field": "username",
    "source": "body",
    "message": "username must have at least 3 characters"
  }
]

Trigger a validation error

curl -X POST https://quanta-api-backend.vercel.app/endpoints/fetch/users \
  -H "x-collection-api-key: YOUR_COLLECTION_KEY" \
  -H "Content-Type: application/json" \
  -d '{"username":"ab"}'

Validation beats simulationIf a request fails validation, you get 400 even when the error ratio is 100 and a pool entry exists.