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POST
Create speech

Authorizations

Authorization
string
header
required

API key as bearer token in Authorization header

Body

application/json

Text-to-speech request input

input
string
required

Text to synthesize

Example:

"Hello world"

model
string
required

TTS model identifier

Example:

"mistralai/voxtral-mini-tts-2603"

input_references
object[]

Reference content for stateless voice cloning or voice design. Audio mode: one to three input_audio parts, each optionally paired with a text part carrying its transcript (a single clip accepts its transcript before or after it; with multiple clips each transcript immediately follows its clip); only routed to endpoints that support voice cloning (and multiple references when more than one part is sent). Image mode: exactly one image_url part; only routed to endpoints that support image references. The two modes cannot be mixed. An empty array is treated as no reference.

Reference content part for stateless voice cloning or voice design

Example:
Example:
provider
object

Provider-specific passthrough configuration

response_format
enum<string>
default:pcm

Audio output format

Available options:
mp3,
pcm
Example:

"pcm"

session_id
string

A unique identifier for grouping related requests (e.g., a conversation or agent workflow). Used for observability grouping in Broadcast and private logging; never sent to the provider. If provided in both the request body and the x-session-id header, the body value takes precedence. Maximum of 256 characters.

Maximum string length: 256
Example:

"session-1234"

speed
number<double>

Playback speed multiplier. Only used by models that support it (e.g. OpenAI TTS). Ignored by other providers.

Example:

1

trace
object

Metadata for observability and tracing. Known keys (trace_id, trace_name, span_name, generation_name, parent_span_id) have special handling. Additional keys are passed through as custom metadata to configured broadcast destinations.

Example:
user
string

A unique identifier representing your end-user. Forwarded to Broadcast and private logging as the end-user id; never sent to the provider.

Maximum string length: 256
Example:

"user-1234"

voice
string

Voice identifier (provider-specific).

Minimum string length: 1
Example:

"en_paul_neutral"

Response

Audio bytes stream

Raw audio bytestream. Content-Type varies by requested format (audio/mpeg for mp3, audio/pcm for pcm — 16-bit little-endian).