# invalid_params

> Noptcha API error invalid_params (HTTP 422): what it means and what to do.

Source: https://noptcha.com/docs/errors/invalid_params/

HTTP **422**, `application/problem+json`. When: `params` or `metadata` do not match the schema, or `callback_url` is not allowed.

## What to do

`params` or `metadata` do not match the schema, or `callback_url` breaks the [URL rules](https://noptcha.com/docs/webhooks.md#callback-url-rules) (pointer `/callback_url`). `errors[]` lists each problem as `{pointer, message}`, where `pointer` is a JSON Pointer from the root of the request body (for example `/params/website_key`). The parameters of each type are on its [task type page](https://noptcha.com/docs/task-types.md).

See all codes on [Errors](https://noptcha.com/docs/errors.md). Include the `request_id` when you contact support.