---
title: SCTE-35 Insertion
slug: zen-master/scte-35-insertion
docTags: 
createdAt: 2025-12-24T18:09:02.713Z
---

Zixi supports SCTE-35 Insertion on Sources using the API *(*[ZEN Master API](docId\:SafxBsM3wuvfg1NwpeAau)* )*

The SCTE-35 payload to be inserted must be pre-formed by the customer and encoded as base-64 or hex.

## Setup

:::::WorkflowBlock
:::WorkflowBlockItem
In sources that support SCTE-35 insertion, select **Enable SCTE-35 Manipulation:**

::Image[****]{src="https://api.archbee.com/api/optimize/mzxtTQEvCNIdUNgF2kuwJ/oRh0KK21lwl31l_qktBxQ-20260102-200402.png" size="68" width="770" height="168" position="center" alt="Enable SCTE-35 Manipulation" darkWidth="770" darkHeight="168" showCaption="false"}
:::

::::WorkflowBlockItem
Enter a Null Packet Search Window to designate an appropriate timeout interval when searching for a NULL packet to replace with the SCTE-35 packet to maintain PCR accuracy in CBR streams. If no NULL Packet is detected by the time the timeout is reached, the SCTE-35 will be inserted anyway, breaking PCR Accuracy momentarily. (If stream is VBR, set this to 0)

:::hint{type="info"}
**Note: Pre Broadcaster v19, 0 seconds will still insert immediately for VBR streams, but all other values will have a fixed timeout of 2 seconds**
:::

![Null Packet Window](https://api.archbee.com/api/optimize/mzxtTQEvCNIdUNgF2kuwJ/LClViGZYGA27ghOlB9Bc2-20260102-200914.png)
::::

:::WorkflowBlockItem
Choose whether to Remove Existing SCTE-35 packets or not. (Generally, this is only selected if leveraging a SCTE-35 Modification workflow, not for SCTE-35 injection)
:::
:::::

## Insertion

Use the ZEN Master API to insert the desired SCTE-35 payload encoded as Base64:

- POST  to *https\://api.zen.zixi.com/*v2**/sources/\:sourceId/scte35**
- Payload:

```json
{
  "scte35": "<string>"
}
```