Voice

Stream voice responses from your clone as raw PCM audio.

Stream Voice Response

Send a text message to your clone and receive the response as a real-time audio stream.

Endpoint: POST /v3/voice/stream

Prerequisites:

• The clone must have a voice configured.

• A conversation must already exist (create one with POST /v3/conversation first).

Request body:

Field	Type	Required	Description
conversation_id	string	Yes	UUID of an existing conversation
message	string	Yes	User message (1 - 10,000 characters)

Example request:

curl -X POST "https://api.delphi.ai/v3/voice/stream" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "conversation_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
    "message": "What are your thoughts on AI safety?"
  }' \
  --output response.pcm

Response:

Binary stream of raw PCM audio data (application/octet-stream).

Response headers:

Header	Value	Description
X-Audio-Format	pcm_24000_16_mono	Audio format identifier
X-Audio-Sample-Rate	24000	Sample rate in Hz
X-Audio-Bits-Per-Sample	16	Bit depth
X-Audio-Channels	1	Mono audio

Playing the audio:

# Convert PCM to WAV using ffmpeg
ffmpeg -f s16le -ar 24000 -ac 1 -i response.pcm response.wav

Synthesize Voice

Convert raw text to audio using your clone's configured voice. Unlike Voice Stream, this does not generate a clone response — it speaks the exact text you provide.

Endpoint: POST /v3/voice/synthesize

Prerequisites:

• The clone must have a voice configured.

Request body

Parameter	Type	Required	Description
text	string	Yes	Text to synthesize (1–10,000 characters)

Query parameters

Parameter	Type	Required	Default	Description
stream	boolean	No	false	Stream raw PCM bytes instead of JSON

Example request (batch)

curl -X POST "https://api.delphi.ai/v3/voice/synthesize" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Hello, this is a test of the synthesis endpoint."
  }'

Example response

{
  "audio": "8/8AABcAHAAhAC8AKQAmADkALAA2AEgANwArACI..."
}

The audio field is base64-encoded raw PCM data (24 kHz, 16-bit signed, mono, little-endian).

Decoding the audio

echo "<base64_audio>" | base64 -d > output.pcm
ffmpeg -f s16le -ar 24000 -ac 1 -i output.pcm output.wav

Example request (streaming)

curl -X POST "https://api.delphi.ai/v3/voice/synthesize?stream=true" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Hello, this is a test of the streaming synthesis endpoint."
  }' \
  --output synthesized.pcm

Response

Binary stream of raw PCM audio data (application/octet-stream).

Response headers

Header	Value	Description
X-Audio-Format	pcm_24000_16_mono	Audio format identifier
X-Audio-Sample-Rate	24000	Sample rate in Hz
X-Audio-Bits-Per-Sample	16	Bit depth
X-Audio-Channels	1	Mono audio

Playing the audio

ffmpeg -f s16le -ar 24000 -ac 1 -i synthesized.pcm synthesized.wav