> For a complete index of all SignalWire documentation pages, fetch https://signalwire.com/docs/llms.txt

# Speechify

> Learn how to use Speechify's Simba TTS voices with SignalWire AI Voice applications.

Speechify is a text-to-speech engine offering natural voices built on its Simba model family.

## Models

SignalWire supports the following Speechify models.
See [Speechify's documentation](https://docs.sws.speechify.com/) for more detail.

| Model                | Description                                        |
| -------------------- | -------------------------------------------------- |
| `simba-3.0`          | **Default.** Current-generation multilingual model |
| `simba-3.2`          | English-only model with the lowest latency         |
| `simba-english`      | Legacy English model                               |
| `simba-multilingual` | Legacy multilingual model                          |

Model availability varies per voice and per workspace — an unavailable voice and model
pairing fails. Test your combination before deploying.

## Voices

Press play to audition any Speechify voice, then **copy config** to grab the value for SWML or your SDK.

Speechify voice IDs come from its voice list API (for example, `alicia` or `alton`) —
use the voice's **ID**, not its display name. The default voice is `alicia`,
an American English female voice.

Browse the available voices in Speechify's documentation:

#### [Speechify TTS docs](https://docs.sws.speechify.com/)

Reference for voices, models, and languages.

#### [Speechify API console](https://console.sws.speechify.com/)

Preview voices and manage your Speechify workspace.

## Languages

Set the language as an ISO 639-1 code with a region, such as `en-US`.
The `simba-3.0` model is multilingual — it covers English, German, Spanish, French, Italian,
Brazilian Portuguese, and more, and infers the language from your text in multilingual mode.
Refer to [Speechify's docs](https://docs.sws.speechify.com/) for current language coverage.

## Usage

A voice identifier string has three parts: the `speechify` engine code, a voice ID, and an optional model.

**Format**: `speechify.<voiceId>:<model>`

* `voiceId` (required): a Speechify voice ID (for example, `alicia`); see [Voices](#voices).
* `model` (optional): one of the [models](#models) above. Defaults to `simba-3.0`.

**Examples**:

```text
speechify.alicia:simba-3.0
speechify.alicia
```

You can also set the model with the separate
[`model`](/docs/swml/reference/ai/languages#use-voice-strings)
parameter of the [`languages`](/docs/swml/reference/ai/languages) SWML method
instead of appending `:model` to the voice string:

```yaml
languages:
- name: English
  code: en-US
  voice: speechify.alicia
  model: simba-3.0
```

---

## Build with Speechify on SignalWire

### Create a Space and add credit

If you don't have one yet, you'll need to
[create a SignalWire Space](/docs/platform/signing-up-for-a-space).
Be sure to add some credit to test with.

### Add a new Resource

Navigate to the **Resources** tab in your [SignalWire Dashboard](https://my.signalwire.com) and click **+ Add New** to create a new Resource.

### Create a SWML Script

From the Resources menu, select **SWML Script**.
Name it something fun and recognizable.
Ours is titled Speechify Wizard.

Next, paste the following starter script into the text box, and hit <kbd>Save</kbd>:

```yaml
version: 1.0.0
sections:
  main:
  - ai:
      prompt:
        text: |
          You're Alicia, a voice from Speechify's TTS engine!
          Introduce yourself, and have a conversation about programmable unified communications on the SignalWire platform.
      languages:
      - name: English
        code: en-US
        voice: speechify.alicia:simba-3.0
```

### Buy and assign a phone number

Navigate to the **Phone Numbers** section of the Dashboard's left sidebar menu.

Purchase a phone number and assign it to the desired SWML script.

![A purchased phone number showing assignment to a specified Resource.](https://fdr-prod-docs-files-public.s3.us-east-1.amazonaws.com/signalwire.docs.buildwithfern.com/f0b50511622e76d7be927bd442190e2e41a88745515f22bc727fa5b480e23409/assets/images/dashboard/phone-numbers/assign-resource-voice.webp?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6KXJSKKNFOCF7G4B%2F20260811%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20260811T085801Z&X-Amz-Expires=604800&X-Amz-Signature=e06c1bcb851fb23ab4a2b1444818ef646db4eab220a1fa3f270112b34955d1f6&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)

### Give it a call!

Call the number you just assigned to chat with your new AI voice application on the phone.

## Next steps with SWML

Now you've deployed your very first SignalWire voice AI application using Speechify voices.
Next, dive deeper into SWML to explore its capabilities!

#### [Methods reference](/docs/swml)

Documentation for all SWML methods

#### [AI in SWML](/docs/swml/guides)

Build advanced AI applications using SignalWire Markup Language

#### [Guides](/docs/swml/guides)

SWML guides and demo applications