# event-type-missing

The request leaves out an **[event type](/docs/eventsourcingdb/event-types)**.

- **Routes:** `write-events`, `read-event-type`, and `register-event-schema`
- **Description:** `event type is missing: expected a reverse domain name such as 'io.eventsourcingdb.library.book-acquired'`
- **Details:** When writing events, **`event`**, the place of the event in its list, counting from 0. On the other routes, none; `details` is an empty object.

## Why It Happens

Every event has a type, and reading an event type or registering a schema for one needs to know which. The database reports this error when **`type` is left out or is an empty string**, in an event of a write or at the top level of the request. A typical cause is a type taken from a variable or a setting that turns out to be empty.

A **`fromLatestEvent`** without its type is reported as **[`from-latest-event-incomplete`](/docs/eventsourcingdb/errors/from-latest-event-incomplete)** instead.

## How to Fix It

Send the event type as a reverse domain name, such as `io.eventsourcingdb.library.book-acquired`. Sending the same request again fails the same way, since the error depends on the request alone.

## Example

For a write whose first event leaves out its type, EventSourcingDB answers with this error, as a line of the stream, and then ends the stream with its `end` item:

```json
{
  "type": "error",
  "data": {
    "code": "https://docs.eventsourcingdb.io/errors/event-type-missing",
    "description": "event type is missing: expected a reverse domain name such as 'io.eventsourcingdb.library.book-acquired'",
    "details": {
      "event": 0
    }
  }
}
```