# What does the VARTA error `validation_error` mean?

FastAPI's own request-schema validation rejected the request before any handler ran.


**HTTP status:** `422`  ·  **Type:** `invalid_request_error`

## What it means

FastAPI's own request-schema validation rejected the request before any handler ran.

## What causes it

Raised by the `/v1` request-validation handler (`backend/app/api/v1/errors.py`) whenever a request body fails schema validation — a field of the wrong type, or missing a required key the model declares.

## What to do

Read `message` for the specific validation failure and `param` for the field name (drawn from the validator's error location), then fix that field's type or presence.