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

# Setup TTS Fallback

> Configure a fallback voice so your UponAI agent keeps talking even when a TTS provider has an outage.

<Info>
  If you are using a platform voice, fallback is handled automatically — no additional setup is required. The steps below only apply if you are using a custom or third-party provider voice.
</Info>

When a TTS provider experiences an outage or temporary issue, your agent needs to keep talking. Fallback switches to a different voice provider seamlessly during the call.

## Default Fallback Behavior

If no custom TTS fallback is configured, UponAI uses a default fallback plan:

* Uses a voice of the same gender as the original (if the original voice has a gender field)
* Falls back to the next available voice in the fallback list in order
* Once switched to a fallback voice, the agent **stays on that voice** for the rest of the call — even if the original provider recovers — to avoid jarring mid-call voice changes

## Setup a Custom Fallback Plan

Configure your own fallback plan so the replacement voice sounds as close as possible to the original.

<Steps>
  <Step title="Open Security & Fallback Settings">
    Go to your agent settings and open the **Security & Fallback Settings** panel.
  </Step>

  <Step title="Add fallback voices">
    Add one or more fallback voices. Each fallback voice must use a **different TTS provider** from the original voice and from each other.
  </Step>

  <Step title="Order your fallbacks">
    Arrange fallback voices in priority order. UponAI tries each in sequence if the previous provider is unavailable.
  </Step>
</Steps>

<Warning>
  You cannot use the same TTS provider for both the primary voice and a fallback voice.
</Warning>