---
title: "TTS Http Alpha"
slug: "dataflow-nodes-tts-http"
updated: 2025-12-10T09:48:20Z
published: 2025-12-10T09:48:20Z
canonical: "docs.knovvu.com/dataflow-nodes-tts-http"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.knovvu.com/llms.txt
> Use this file to discover all available pages before exploring further.

# TTS Http

Text To Speech Integration Node

## Parameters
| <div style="width:170px">name</div> | description | <div style="width:120px">default</div> |
|---|---|---|
| Address | Address of the SESTEK TTS service  | http://core-tts |
| IgnoreSslErrors | ignore any certificate errors if SESTEK TTS address contains https | false |
| ConnectionTimeoutMsec | Connect timeout for provided address in milliseconds | 20000 |
| Language | Language will be used in order to determine which of the provided voices will be used for TTS | -|
| CredentialId | Id of the credential that will be used for TTS requests. This parameter is only necessary if a cloud SESTEKTTS deployment is used. You must leave this empty for on-premise deployments. |None(On-Prem)|
|Voices|The array of voices that are available for use|-|
|Volume|Controls the output loudness of the synthesized speech. Accepts values between 0.0 (muted) and 2.0|1.0|
|Rate|Controls the playback speed of the synthesized speech. Accepts values between 0.33 (slower) and 3.0 (faster).|1.0|


## Inputs

### Audio
none


### Events
| name | description | known nodes that generate this event |
|---|---|---|
| Every Event that Contains the `Data.Text` field | A TTS Synthesis audio can be generated from any event that is text based. Users can also generate their custom event that has `Data.Text` and send it through the [Entry](/v1/docs/dataflow-nodes-entry), or [External Relay](/v1/docs/dataflow-nodes-external-relay) nodes.  | [SR Http](/v1/docs/dataflow-nodes-speech-recognition-sr-http), [SR WebSocket](/v1/docs/dataflow-nodes-speech-recognition-sr-websocket), [Translate](/v1/docs/dataflow-nodes-translate)|
|Language Change| Change the current voice to match the desired language if there is an available voice. In case of multiple available voices, the first voice in the list will be used.  |Text Language Identifier, [Language Identifier](/v1/docs/dataflow-nodes-language-identifier). |

## Outputs

### Audio
&emsp;Synthesized speech is sent to output

### Events
| name | description |
|---|---|
| [Start of TTS Fragment](/v1/docs/events#start-of-tts-fragment) | This event is sent just before a TTS operation writes the result to Audio output. Contains the Text that was used for the synthesis under the `Data.Text` field.  |
| [End of TTS Fragment](/v1/docs/events#end-of-tts-fragment) | This event is send just after a TTS operation has finished writing to Audio output. |

## Remarks

### Custom TTS Event

A sample tts-request event would look as follows.
```json
{
    "Event": {
        "Name": "Custom TTS Event",
        "Data" : {
            "Text": "hello world"
        }
    }
}
```
`Data.Text`: The text that will be synthesized.

 :::(Info) (Sending Custom Events to Projects)
To learn more about sending `Events` to projects, you can check the [HTTP](/v1/docs/dataflow-integrations-http) and [External Relay](/v1/docs/dataflow-nodes-external-relay) pages.
:::

### Project Structure
A minimum viable TTS project that works with custom events can be built as such:
<center>
    
![image.png](https://cdn.document360.io/9bca2910-6a3b-4224-9470-43f91f9a6d57/Images/Documentation/image%28884%29.png){height="" width=""}
</center>

An example that utilizes two TTS Http nodes with different `Voices` can be built as seen below. In order to choose which node does the synthesis, we can change the `Channel` variable in our custom event.
<center>
    
![image.png](https://cdn.document360.io/9bca2910-6a3b-4224-9470-43f91f9a6d57/Images/Documentation/image%28885%29.png){height="" width=""}
</center>

Finally, here's an example project that doesn't count on external events, instead, it does simultaneous translation of speech and returns audio segments to the client.

<center>

![image.png](https://cdn.document360.io/9bca2910-6a3b-4224-9470-43f91f9a6d57/Images/Documentation/image%28886%29.png){height="" width=""}
</center>

### Supported flow types 
Stream, Batch


## Release Notes 

<div style="max-height: 200px; overflow-y: auto; overflow-x: hidden"> 
     <details>
        <summary> <strong> v4.4.0</strong> </summary>
        <ul>
          <li>Added node-level configuration for <strong>Volume</strong> (0–2.0) and <strong>Rate</strong> (0.33–3.0).</li>
        </ul>
    </details>
    <details>
        <summary> <strong> v3.6.0</strong> </summary>
        <ul>
            <li>Improved Observability for request timings.</li>
        </ul>
    </details>
    <details>
        <summary> <strong> v3.4.0</strong> </summary>
        <ul>
            <li>Added synthesized Text information under the data field in `Start Of TTS Fragment`.</li>
        </ul>
    </details>
    <details>
        <summary> <strong> v3.0.0</strong> </summary>
        <ul>
            <li>Renamed "Models" to "Voices".</li>
        </ul>
    </details>
     <details>
        <summary> <strong> v2.0.0</strong> </summary>
        <ul>
            <li>Renamed from "TTS Http Alpha" to "TTS Http".</li>
        </ul>
    </details>
    <details>
        <summary> <strong> v1.1.0</strong> </summary>
        <ul>
            <li>Introduced node.</li>
        </ul>
    </details>
</div>