We’ve introduced a new Video Translation model, quality, designed to deliver significantly more natural lip-sync and context-aware translations. This new mode is optional and available via the /v2/video_translate endpoint using the new mode parameter.

Available Modes

Fast Mode (default)

mode: fast

Cost: 3 credits per minute

Optimized for speed and standard translations, especially effective for videos with limited facial movement.

Quality Mode (new)

mode: quality

Cost: 6 credits per minute

Produces highly natural, context-aware lip-sync for premium translation results.

You may now specify the desired mode when calling the /v2/video_translate endpoint. If no mode is provided, it will default to fast.

Reference: https://docs.heygen.com/reference/video-translate#/

We’ve added a new endpoint to retrieve dynamic and custom variables defined in your AI Studio templates.

Endpoint: v3/template/<template_id> This endpoint allows developers to programmatically access all variable definitions — including avatar, text and elements and media (e.g. image, video, etc.) — that can be dynamically populated during video generation. It enables full integration of AI-powered avatar video creation workflows using your own template schema.

Reference: https://docs.heygen.com/reference/get-template-v3#/

We've added the new endpoint to Create Avatar IV

Endpoint: v2/video/av4/generate - To enable programmatic generation of AI-powered avatar videos using advanced photorealistic avatar technology. This endpoint allows you to create videos with custom avatars speaking your provided text or audio.

Reference: https://docs.heygen.com/reference/create-avatar-iv-video

We’ve expanded the Asset API with new endpoints for easier asset management:

• Endpoint: /v1/asset/list — List assets with pagination and filters for file_type and folder_id.
  Reference: https://docs.heygen.com/reference/list-assets
• Endpoint: /v1/asset/<asset_id>/delete — Delete a single asset by its ID.
  Reference: https://docs.heygen.com/reference/delete-asset

Endpoint: /v1/streaming.new
Reference: https://docs.heygen.com/reference/new-session

Added new STT provider: AssemblyAI. It is now the default provider for English language transcription.

Endpoint: /v1/streaming.new
Reference: https://docs.heygen.com/reference/new-session

A new parameter activity_idle_timeout has been added to the streaming.new endpoint.
It specifies the maximum idle time (in seconds) after the last user interaction before the session is marked as inactive.Default: 120 seconds, Range: 30 to 3600 seconds. This gives you greater control over session lifecycle management and resource usage.

Endpoint: /v1/streaming.keep_alive
Reference: https://docs.heygen.com/reference/keep-alive

A new /v1/streaming.keep_alive endpoint has been introduced to reset the idle timeout counter for an active streaming session. Use this endpoint to keep the session alive and prevent it from timing out due to inactivity.

Endpoint: /v1/streaming/knowledge_base/*
Reference: https://docs.heygen.com/reference/list-knowledge-bases

We’ve added new Knowledge Base Management endpoints! You can now list, create, update, and delete knowledge bases for your interactive avatars.

Endpoint: /v2/avatar/{avatar_id}/details
Reference: https://docs.heygen.com/reference/retrieve-avatar-details

We’ve added the Retrieve Avatar Details endpoint! Retrieve detailed information for a specific avatar by providing its avatar_id.

Endpoint: /v2/voices/locales
Reference: https://docs.heygen.com/reference/list-all-locales-for-voices

We’ve added the List All Locales for Voices endpoint! Retrieve a full list of available voice locales (like en-US, pt-BR, etc.) that you can use with multilingual voices when generating videos. Before using, check if the voice supports locales via the support_locale attribute from /v2/voices.