# `400` - Missing client ID

## Description

The `upvest-client-id` header is missing in the request.

## How to fix

Provide `upvest-client-id` in the request header.

## Example

```http
HTTP/1.1 400 Bad Request
content-length: 176
content-type: application/problem+json
date: Mon, 11 Oct 2021 10:42:01 GMT
upvest-request-id: e7378103-7d45-4052-a049-7c9ac88d041c

{
    "type": "https://docs.upvest.co/errors/missing_client_id",
    "status": 400,
    "title": "Missing client ID",
    "request_id": "e7378103-7d45-4052-a049-7c9ac88d041c"
}
```