> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gradium.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Release Notes

> Latest updates and improvements to the Gradium API

## 2026.07.22

**Keyword Boosting for Speech-to-Text**

Get the vocabulary specific to your product transcribed correctly: brand and product names, people, places, drugs, and jargon. Pass a dictionary of the terms you care about in your STT `json_config`, and the model gives them priority while decoding, in real time, with no retraining. Rare, specific words that a general model rarely sees now come through correctly.

The `keywords` block takes a `words` dictionary and a `boost` weight. `boost` is applied in log-probability space, so its effect is exponential and a small value goes a long way. We recommend a boost of `3`. A dictionary holds up to 500 single-token entries, matched by exact case and accent.

Dictionaries can also be saved in Gradium Studio under Vocabulary, in the Keyword boost tab, then used in a session by passing their id as `keyword_boost_id`.

See the [Keyword Boosting recipe](/guides/recipes/keyword-boosting) and [Transcription Settings](/guides/transcription-settings) for details.

## 2026.06.10

Gradium TTS now runs on an upgraded default model focused on more expressive speech and better reliable pronunciation for production voice agents.

Improved natural prosody, phrasing, intonation, and pacing. This is especially noticeable in conversational turns and longer passages.

The model is better at spelling out email addresses, reference numbers, confirmation codes, and acronyms such as `API`, `SQL`, and `URL`.

The upgraded model is now the default. If your integration uses the default model, you are already on the new Gradium TTS model with no code changes required.

Every voice from the previous model generation is available on the upgraded model, including custom voices. You do not need to re-clone or recreate voices.

Integrations pinned to a specific model can switch by changing the model identifier. To stay on the previous model temporarily, set `model_name` to `gradium-tts-202602`. The previous model will be gradually phased out over the next few weeks.

## 2026.02

We're excited to announce major updates to the Gradium API and Gradium Studio, delivering enhanced text-to-speech (TTS) and speech-to-text (STT) capabilities for developers and enterprises.

**Advanced TTS and STT Models**

Experience our latest text-to-speech model and speech recognition model with improved audio quality, accuracy, and natural-sounding voice generation. Perfect for voice applications, transcription services, and conversational AI. Now by default.

**Custom Pronunciation Dictionaries**

Take control of speech synthesis with pronunciation dictionaries. Ensure brand names, technical terminology, and industry-specific acronyms are pronounced correctly every time. Ideal for healthcare, finance, and industry specific applications.

**WebSocket Multiplexing for Real-Time Audio**

Boost performance with multiplexing support: process multiple TTS or STT requests simultaneously over a single WebSocket connection. Reduce latency, minimize connection overhead, and scale efficiently for high-volume applications.

**Gradium Referral Program**

Love Gradium? Join our referral program: share Gradium with your network and earn up to 9M API credits while your referrals get exclusive discounts. Win-win for developers and businesses alike.

**AWS Marketplace & SageMaker AI Deployment**

Deploy Gradium TTS and ASR models directly on AWS SageMaker with full bidirectional streaming support. Accelerate your deployment timeline while keeping your voice AI infrastructure secure within your private cloud network. Now available on AWS Marketplace.

Feedbacks are always welcome, do not hesitate to join our [discord channel](https://discord.com/invite/bcysuPRzXE)!