# Gradium API

> Developer documentation for Gradium's low-latency Text-to-Speech and Speech-to-Text APIs, including SDK guides, WebSocket streaming, REST endpoints, voices, and pronunciation tools.

## Docs

- [Create Pronunciation Dictionary](https://docs.gradium.ai/api-reference/endpoint/create-pronunciation.md): Create a Gradium pronunciation dictionary with language-specific rewrite rules.
- [Create Voice](https://docs.gradium.ai/api-reference/endpoint/create-voice.md): Create a custom Gradium voice from an uploaded audio sample.
- [Delete Pronunciation Dictionary](https://docs.gradium.ai/api-reference/endpoint/delete-pronunciation.md): Delete a Gradium pronunciation dictionary by UID.
- [Delete Voice](https://docs.gradium.ai/api-reference/endpoint/delete-voice.md): Delete a custom Gradium voice by voice UID.
- [Get Credits](https://docs.gradium.ai/api-reference/endpoint/get-credits.md): Get the current Gradium credit balance for the authenticated subscription.
- [Get Pronunciation Dictionary](https://docs.gradium.ai/api-reference/endpoint/get-pronunciation.md): Retrieve a Gradium pronunciation dictionary and its rewrite rules by UID.
- [Get Voice](https://docs.gradium.ai/api-reference/endpoint/get-voice.md): Retrieve metadata for a Gradium voice by voice UID.
- [Get Voices](https://docs.gradium.ai/api-reference/endpoint/get-voices.md): List Gradium voices available to the authenticated organization.
- [List Pronunciation Dictionaries](https://docs.gradium.ai/api-reference/endpoint/list-pronunciations.md): List pronunciation dictionaries for the authenticated Gradium organization.
- [STT POST Endpoint](https://docs.gradium.ai/api-reference/endpoint/stt-post.md): Transcribe a complete audio file with Gradium speech-to-text over HTTP POST.
- [STT WebSocket Stream](https://docs.gradium.ai/api-reference/endpoint/stt-websocket.md): Stream audio to Gradium speech-to-text over WebSocket for real-time transcription.
- [TTS POST Endpoint](https://docs.gradium.ai/api-reference/endpoint/tts-post.md): Generate text-to-speech audio from a complete text block with HTTP POST.
- [TTS WebSocket Stream](https://docs.gradium.ai/api-reference/endpoint/tts-websocket.md): Stream real-time Gradium text-to-speech audio over WebSocket.
- [Update Pronunciation Dictionary](https://docs.gradium.ai/api-reference/endpoint/update-pronunciation.md): Update a Gradium pronunciation dictionary and its rewrite rules.
- [Update Voice](https://docs.gradium.ai/api-reference/endpoint/update-voice.md): Update metadata for an existing custom Gradium voice.
- [API Reference](https://docs.gradium.ai/api-reference/introduction.md): Gradium API endpoints for Text-to-Speech, Speech-to-Text, Voices, Pronunciations, and Metering
- [Credits](https://docs.gradium.ai/guides/credits.md): Monitor and manage your API credit balance
- [Errors](https://docs.gradium.ai/guides/errors.md): How errors are reported across REST, WebSocket, and streamed responses
- [FAQ](https://docs.gradium.ai/guides/faq.md): Frequently asked questions about the Gradium API
- [Installation](https://docs.gradium.ai/guides/installation.md): Install the Gradium Python SDK and get started
- [Introduction](https://docs.gradium.ai/guides/introduction.md): Low-latency, high-quality Text-to-Speech and Speech-to-Text API
- [Limits](https://docs.gradium.ai/guides/limits.md): Session duration, character limits, audio formats, and concurrency
- [Multiplexing](https://docs.gradium.ai/guides/multiplexing.md): Send multiple TTS requests over a single WebSocket connection
- [Release Notes](https://docs.gradium.ai/guides/release-notes.md): Latest updates and improvements to the Gradium API
- [Speech-to-Text (WebSocket)](https://docs.gradium.ai/guides/speech-to-text.md): Real-time speech-to-text streaming over WebSocket with semantic VAD and flush
- [Speech-to-Text Overview](https://docs.gradium.ai/guides/speech-to-text-overview.md): When to use the WebSocket API vs the REST endpoint, and how the pieces fit together
- [Speech-to-Text (REST)](https://docs.gradium.ai/guides/speech-to-text-rest.md): One-shot transcription of complete audio files via HTTP POST
- [Text Rewriting Rules](https://docs.gradium.ai/guides/text-rewriting.md): Normalize and expand text patterns for better TTS pronunciation
- [Text-to-Speech (WebSocket)](https://docs.gradium.ai/guides/text-to-speech.md): Convert text to natural-sounding speech via the Gradium SDK and WebSocket
- [Text-to-Speech Overview](https://docs.gradium.ai/guides/text-to-speech-overview.md): When to use the WebSocket API vs the REST endpoint, and how the pieces fit together
- [Text-to-Speech (REST)](https://docs.gradium.ai/guides/text-to-speech-rest.md): One-shot synthesis of a complete text block via HTTP POST
- [Transcription Settings](https://docs.gradium.ai/guides/transcription-settings.md): Fine-tune STT: language, temperature, latency vs. quality tradeoffs
- [Voice Settings](https://docs.gradium.ai/guides/voice-settings.md): Fine-tune TTS output: speed, temperature, voice similarity, rewrite rules
- [All Voices](https://docs.gradium.ai/guides/voices/all-voices.md): Browse the full catalog of 237 voices across five languages
- [Custom Voices](https://docs.gradium.ai/guides/voices/custom-voices.md): Clone your own voice using a short audio sample
- [Flagship Voices](https://docs.gradium.ai/guides/voices/flagship-voices.md): Our top curated voices across multiple languages
- [Manage Voices](https://docs.gradium.ai/guides/voices/manage-voices.md): List, update, and delete your custom voices
- [Overview](https://docs.gradium.ai/guides/voices/overview.md): Explore the Gradium voice library
- [WebSocket Stream Options](https://docs.gradium.ai/guides/websocket-stream-options.md): Connection initialisation flags shared by tts_realtime and stt_realtime
- [Gradium API Documentation](https://docs.gradium.ai/index.md): Build voice apps with Gradium's low-latency Text-to-Speech and Speech-to-Text APIs, SDK guides, streaming examples, voices, and pronunciation tools.

## OpenAPI Specs

- [openapi](https://docs.gradium.ai/api-reference/openapi.json)

## Optional

- [Support](mailto:support@gradium.ai)