> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://space.respeecher.com/docs/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://space.respeecher.com/docs/_mcp/server.

# Choosing an API

> Compare the Space API and the Marketplace API and choose the right one for your use case.

Respeecher offers two separate APIs. They have different base URLs, different
authentication, and different strengths — so it's worth picking deliberately
before you start building.

#### [Space API](/docs/space/quickstart)

Realtime, low-latency **text-to-speech** streaming. The right default for
most TTS use cases, including voice agents.

#### [Marketplace API](/docs/marketplace/api-overview)

**Speech-to-speech** conversion and project-based workflows: projects,
folders, recordings, calibration, and conversion orders.

## At a glance

|                    | Space API                                                                     | Marketplace API                                                   |
| ------------------ | ----------------------------------------------------------------------------- | ----------------------------------------------------------------- |
| **Best for**       | Realtime streaming TTS                                                        | Speech-to-speech, batch/project workflows                         |
| **Speech-to-text** | Text-to-speech only                                                           | Speech-to-speech **and** text-to-speech                           |
| **Base URL**       | `https://api.respeecher.com`                                                  | `https://gateway.respeecher.com`                                  |
| **Auth header**    | `X-API-Key`                                                                   | `api-key` (or session cookie + `X-Csrf-Token`)                    |
| **Get a key**      | [Playground](https://space.respeecher.com/api-keys)                           | [Marketplace account](https://marketplace.respeecher.com/account) |
| **Streaming**      | SSE and WebSocket                                                             | Not streaming — submit an order, poll, then download              |
| **SDKs**           | [Python](/docs/space/sdks/python), [TypeScript](/docs/space/sdks/type-script) | —                                                                 |
| **Integrations**   | LiveKit, Pipecat, Ultravox, VAPI                                              | Pro Tools plugin                                                  |

> **Warning**
>
> The two APIs use **different** API key headers — `X-API-Key` for Space and
> `api-key` for Marketplace — and the keys are issued from different places. Keys
> are not interchangeable between the two.

## Choose the Space API if…

* You are generating speech from **text** and want it as fast as possible.
* You need to **stream** audio as it is generated, over SSE or WebSockets.
* You are building a **voice agent** or any interactive experience where latency matters.
* You want a **Python or TypeScript SDK**, or a drop-in integration with
  LiveKit, Pipecat, Ultravox, or VAPI.

Start with the [Quickstart](/docs/space/quickstart).

## Choose the Marketplace API if…

* You are converting **existing audio** from one voice to another (speech-to-speech).
* You want to organize work into **projects, folders, and recordings** rather
  than one-off requests.
* You need **calibration** to match pitch between the source and target voice.
* You want to convert to a specific **accent**, or export a whole project as a `.zip`.
* You are working in **Avid Pro Tools** and want the
  [plugin](/docs/marketplace/pro-tools-plugin).

Start with the [API Overview](/docs/marketplace/api-overview).

## Still not sure?

If your use case is "turn this text into audio," use the **Space API**. It is
faster, simpler to authenticate against, and has SDKs.

Reach for the Marketplace API when you specifically need speech-to-speech
conversion or the project/folder/recording workflow around it.