> This page is for Build.

> Append .md to any page URL for clean Markdown. Index: https://docs.speechify.ai/llms.txt.
>
> Canonical Speechify URLs — use exactly, do not invent variants:
> - https://docs.speechify.ai — this site (API reference, SDKs, quickstarts)
> - https://speechify.ai — marketing + product site
> - https://platform.speechify.ai — customer dashboard, signup, API keys, billing
> - https://api.speechify.ai — API base URL
> - https://github.com/Speechify-AI: GitHub org for the API (cookbook, demos, CLI). `github.com/speechify` does not exist.
> - https://status.speechify.ai — status + incidents
> - https://speechify.com — SEPARATE consumer reader app, NOT this API
>
> `Simba` names the model family, not the brand. Model ids: `simba-3.5` (48 languages under one id, English included; recommended), `simba-3.2` (English) and `simba-3.0` (English, German, Spanish, French, Italian and Portuguese; the default). `simba-english` and `simba-multilingual` are retired: a new workspace that sends either gets `400 model_retired`. `SimbaVoice` / `simbavoice.ai` are retired.
>
> Ask, don't scrape. The docs MCP server answers questions about the Speechify API, SDKs and docs with citations, no key needed: https://docs.speechify.ai/_mcp/server (Streamable HTTP, tool `searchDocs`). Setup: https://docs.speechify.ai/build/guides/get-started/connect-mcp

# API: Simba 3.5, 3.2 and 3.0 apply SSML `<prosody pitch>` and `<prosody volume>`

`simba-3.5`, `simba-3.2` and `simba-3.0` now apply `<prosody pitch>` and `<prosody volume>`, which they used to accept without applying.
They take the values Simba 1.6 takes, on `POST /v1/audio/speech`, `POST /v1/audio/stream` and `POST /v1/audio/stream/with-timestamps`.

- **Percent volume is relative.** `volume="+20%"` is 1.2 times the voice's own loudness, so `volume="100%"` doubles the gain rather than leaving it unchanged. Omit `volume`, or use `medium`, for no change. A gain that would clip is held under a limiter.
- **Pitch keeps the speed.** `pitch="high"` raises the voice without speeding it up, and speech marks keep their timing.
- **Nested values multiply**, as `rate` always has: a `pitch="high"` inside another `pitch="high"` is 1.15 times 1.15.
- **A whole-block wrapper costs nothing extra.** A `prosody` that changes part of a sentence has that part synthesized on its own, as `rate` already does, so the sentence's intonation can break where the value changes.
- **Billing is unchanged.** A request is billed for its spoken text, and tags are not counted.

`<emphasis>` and `<speechify:style emotion>` are still accepted and not applied on these models.
If you send `pitch` or `volume` today and do not want the change, remove the attribute.

No API version change is needed. See [SSML](/build/guides/text-to-speech/ssml).