---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/91103#article
headline: "91103: Event type list is empty"
url: https://www.twilio.com/docs/api/errors/91103
inLanguage: en
dateModified: 2026-06-09T11:00:42.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 91103: Event type list is empty

Log Type: APPLICATION

Log Level: ERROR

## Description

This error occurs when you create or update an Event Streams subscription without providing any event types in the `Types` list. Event Streams subscriptions require a set of event type and schema version pairs, and the Subscription resource requires the `types` request parameter.

### Possible causes

* Your request to the Subscription resource included an empty `Types` array.
* Your application built the subscription payload without adding any event type entries before sending the request.

### Possible solutions

* Add at least one event type to the `Types` parameter when you create the subscription. Each entry should identify an existing event type and can include a `schema_version`.
* Verify the event types you want to subscribe to before sending the request. Use the Event Type resource to review available event types and schemas.
* If you manage event types after creating the subscription, use the Subscribed Event resource to add event types to the subscription instead of submitting an empty list.

#### Additional resources

* [Event Streams overview](/docs/events)
* [Subscription resource](/docs/events/event-streams/subscription)
* [Subscribed Event resource](/docs/events/event-streams/subscription/subscribed-event-api)