> 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: published rate & concurrency limits, and a `docs_url` on 429s

The [API limits reference](https://docs.speechify.ai/build/guides/concepts/api-limits) now lists the per-plan **rate limits** (sustained requests per second) and **concurrency limits** (simultaneous in-flight requests) for every plan on the audio (TTS) surface. Limits apply per account, not per API key.

`429 Too Many Requests` responses are now self-describing:

- A `Retry-After` header tells you when to retry.
- The error `code` distinguishes the two cases: `rate_limited` (too many requests per second) versus `concurrency_limited` (too many simultaneous requests).
- The error envelope carries a `docs_url` that links straight to the limits reference, which lists your plan's limits and how to raise them.

Rate and concurrency limits rise with your plan, and Enterprise limits are starting points rather than hard caps.