convozen 0.3.8

Python SDK for ConvoZen TTS and STT services

ConvoZen Voice SDK

Text-to-Speech (TTS) and Speech-to-Text (STT) for Python.

One API key for both TTS and STT.

Install

pip install convozen

Requires Python 3.9+

---

TTS — Convert Text to Speech

Copy and run:

import convozen

client = convozen.Client(api_key="your-api-key")

audio = client.tts.synthesize("नमस्ते… मुझे आपके सर्विस के बारे में थोड़ी जानकारी चाहिए।", language="hi")

with open("output.wav", "wb") as f:
    f.write(audio)

With options:

import convozen

client = convozen.Client(api_key="your-api-key")

audio = client.tts.synthesize(
    text="Welcome to Playground.",
    language="en",          # default: "en"
    voice="roohi",          # default: "roohi"
    model="ragini-v1",      # default: "ragini-v1"
    speed=1.2,              # default: 1.0
)

with open("output.wav", "wb") as f:
    f.write(audio)

Parameters

Parameter	Type	Default	Description
text	str	required	Text to convert to speech
language	str	"en"	Language code (see supported languages below)
voice	str	"roohi"	Voice ID for synthesis (see available voices below)
model	str	"ragini-v1"	TTS model to use. Currently only ragini-v1 is available
speed	float	1.0	Speech speed. 0.5 = half speed, 2.0 = double speed
stream	bool	False	If True, returns audio chunks as they are generated
format	str	"wav"	Audio output format. Currently only wav is supported

Streaming

import convozen

client = convozen.Client(api_key="your-api-key")

for chunk in client.tts.synthesize("Long text here...", language="en", stream=True):
    audio_player.write(chunk)

Available Voices

Voice	ID	Default
Roohi	roohi	Yes
Amaya	amaya
Kiyansh	kiyansh
Neeraj	neeraj
Manya	manya
Nidhi	nidhi
Ira	ira
Trisha	trisha
Charvi	charvi

audio = client.tts.synthesize("Hello", language="en", voice="roohi")

---

STT — Convert Speech to Text

Copy and run:

import convozen

client = convozen.Client(api_key="your-api-key")

result = client.stt.transcribe("recording.wav")
print(result.text)    # "hello how can I help you"
print(result.score)   # -2.45  (confidence — closer to 0 is better)

By default this transcribes mono, single-speaker audio and returns an STTResponse.

---

Word-level timestamps

Timestamps are opt-in — pass word_time_stamps=True:

result = client.stt.transcribe("recording.wav", word_time_stamps=True)

for w in result.word_timestamps:
    print(f"{w.word}  {w.start_s:.2f}s – {w.end_s:.2f}s")

Works on both the transcript and diarization paths (per-turn timestamps on DiarizeTurn.word_timestamps).

---

Speaker Diarization (mono)

For a mono recording with multiple speakers, set diarize=True to get a per-speaker breakdown (DiarizeResponse):

result = client.stt.transcribe("call.wav", diarize=True)

for turn in result.turns:
    print(f"[{turn.speaker_id}]  {turn.start_sec:.1f}s – {turn.end_sec:.1f}s")
    print(f"  {turn.transcript}")

# [s0]  0.0s – 3.2s
#   Hello, this is support. How can I help you?
# [s1]  4.0s – 7.8s
#   Hi, I'd like to reschedule my appointment.

If you know how many speakers to expect, pass n_speakers (an integer 2–4) as a hint. Leave it as None (default) to auto-detect:

result = client.stt.transcribe("interview.wav", diarize=True, n_speakers=2)

Response fields (DiarizeResponse):

Field	Type	Description
turns	list[DiarizeTurn]	Speaker turns in order
num_speakers	int	Number of distinct speakers detected
total_duration_sec	float	Total audio duration in seconds

Each DiarizeTurn has speaker_id, start_sec, end_sec, transcript, and word_timestamps (populated when word_time_stamps=True).

---

Stereo audio

If each speaker is on a separate channel (e.g. a 2-channel call recording), set audio_channels="stereo". Each channel is treated as one speaker, and you get a DiarizeResponse:

result = client.stt.transcribe("stereo_call.wav", audio_channels="stereo")

For stereo, keep diarize=False (the channels already are the speakers) and leave n_speakers=None. The declared audio_channels must match the file — a mono file declared "stereo" (or vice-versa) is rejected with a 400.

---

Denoising

For noisy multi-speaker audio, enable denoise=True. It applies on the diarization path (diarize=True or audio_channels="stereo"):

result = client.stt.transcribe("noisy_call.wav", diarize=True, denoise=True)

---

Specify Languages

If you know which languages are spoken in the audio, pass them in lang_tags. This improves accuracy — especially for multilingual audio like Hindi + English call recordings:

result = client.stt.transcribe(
    "recording.wav",
    lang_tags=["hi", "en"],
)
print(result.text)  # "हां मुझे appointment reschedule करना है"

---

Keyword Boosting

Have domain-specific words the model keeps getting wrong? Pass them in keywords and the model will bias towards recognizing them:

# Without keyword boosting: "can you tell me about conversion"
# With keyword boosting:    "can you tell me about convozen"

result = client.stt.transcribe(
    "recording.wav",
    keywords=["convozen", "akshara"],
)

---

Choose a Model

Use model to select which ASR model processes the audio:

result = client.stt.transcribe("recording.wav", model="akshara-pro")   # default
result = client.stt.transcribe("recording.wav", model="akshara-base")

Model	Best for
akshara-pro	Maximum accuracy (default)
akshara-base	Lighter / faster

---

Parameters

Parameter	Type	Default	Description
audio	str | os.PathLike	required	Path to the audio file
model	str	"akshara-pro"	ASR model: "akshara-pro" or "akshara-base"
audio_channels	str	"mono"	"mono" or "stereo". Must match the actual file
diarize	bool	False	True to return per-speaker turns (mono only)
n_speakers	int	None	Expected speaker count (2–4) for mono diarization. None → auto-detect
denoise	bool	False	Apply denoising on the diarization path — helps on noisy audio
lang_tags	list[str]	None	Languages spoken in the audio — improves accuracy when known
word_time_stamps	bool	False	True to return per-word timestamps
blank_penalty	float	None	Penalizes silence/blank tokens; increase to reduce empty gaps. None → derived from lang_tags
keywords	list[str]	None	Domain words the model should bias towards recognizing

When to use what

audio_channels	diarize	n_speakers	Result
"mono"	False	None	Plain transcript → STTResponse
"mono"	True	None	Auto speaker count → DiarizeResponse
"mono"	True	2–4	Hinted speaker count → DiarizeResponse
"stereo"	False	None	Channel-split diarization → DiarizeResponse

Anything outside these rows raises a ValueError (e.g. n_speakers without diarize, n_speakers outside 2–4, diarize=True with "stereo").

---

Supported Languages

Code	Language	TTS	STT
en	English	Yes	Yes
hi	Hindi	Yes	Yes
ta	Tamil	Yes	Yes
te	Telugu	Yes	Yes
kn	Kannada	Yes	Yes
mr	Marathi	—	Yes
bn	Bengali	—	Yes
gu	Gujarati	—	Yes
ml	Malayalam	—	Yes

---

Check Credits

import convozen

client = convozen.Client(api_key="your-api-key")
info = client.account.info()
print(info.credits.tts.balance)
print(info.credits.stt.balance)

---

Error Handling

import convozen
from convozen import AuthenticationError, RateLimitError, APIError

client = convozen.Client(api_key="your-api-key")

try:
    audio = client.tts.synthesize("Hello")
except AuthenticationError:
    print("Invalid API key")
except RateLimitError:
    print("Too many requests")
except APIError as e:
    print(f"Server error: {e}")

---

Standalone Clients

from convozen import TTS, STT

tts = TTS(api_key="your-api-key")
audio = tts.synthesize("Hello", language="hi")

stt = STT(api_key="your-api-key")

# Flat transcript
result = stt.transcribe("recording.wav")
print(result.text)

# Per-speaker diarization (mono, multiple speakers)
result = stt.transcribe("call.wav", diarize=True)
for turn in result.turns:
    print(f"[{turn.speaker_id}] {turn.start_sec:.2f}s – {turn.end_sec:.2f}s : {turn.transcript}")