TTS and EVI API sunset notice
Hume is sunsetting the TTS and EVI APIs. Access ends November 13, 2026 at 12:01 a.m. EST, and both APIs remain fully supported until then. Any data in your account is permanently deleted after November 13, 2026.
Hume AI updates
Last updated · 54 releases tracked since August 2024
A dated log of everything Hume AI has shipped, collected from official Hume AI sources and updated as new releases land.
October 2026 at a glance
Hume AI has shipped 1 update so far in October 2026, mostly API.
This month
1
+1 vs last month
Last 12 months
8
Busiest: November 2025
Most shipped
API
8 releases
Latest Hume AI releases
Newest first. Each entry links to the official page it came from.
October 20261 release
May 20261 release
TTS API additions
Added an experimental temperature parameter to TTS endpoints. Controls sampling temperature for speech generation. Higher values increase variation; lower values increase consistency.
April 20261 release
EVI API additions
Added configurable turn detection and interruption settings to EVI configs. You can now control how EVI handles turn-taking and interruptions on a per-config basis. turn_detection.end_of_turn_silence_ms : How long EVI waits after speech ends before committing a turn (500-3000ms,…
February 20262 releases
TTS API bug fixes
Fixed a bug where duplicate interleaved audio was included in TTS audio output. This resolves an issue where audio chunks could be duplicated and interleaved, resulting in distorted output.
EVI API additions
Added support for new supplemental LLM models: claude-opus-4-6 , gpt-5.1 , gpt-5.1-priority , gpt-5.2 , gpt-5.2-priority . Added support for zero prompt expansion . You can now set prompt_expansion to ZERO when configuring an external LLM, disabling automatic prompt expansion an…
November 20253 releases
EVI API additions
Added support for a new SESSION_SETTINGS chat event in the EVI chat history API. When you fetch chat events via /v0/evi/chats/:id , the response now includes entries that indicate when system settings were updated and which settings were applied.
TTS API additions, EVI API additions
Introduced voice conversion endpoints. Send speech, specify a voice, and receive audio converted to that target voice. POST /v0/tts/voice_conversion/json : JSON response with audio and metadata. POST /v0/tts/voice_conversion/file : Audio file response. EVI API additions Added a…
TTS API additions
Introduced voice conversion endpoints. Send speech, specify a voice, and receive audio converted to that target voice. POST /v0/tts/voice_conversion/json : JSON response with audio and metadata. POST /v0/tts/voice_conversion/file : Audio file response. EVI API additions Added a…
Earlier releases (46)
October 20253 releases
TTS API improvements, EVI API improvements
Octave 2 is now available for use in TTS endpoints. For HTTP endpoints, specify "version": "2" in your request body. ( reference ) For the WebSocket endpoint, specify version=2 in the query parameters of the handshake request. ( reference ) Word and phoneme level timestamps are…
TTS API improvements
Octave 2 is now available for use in TTS endpoints. For HTTP endpoints, specify "version": "2" in your request body. ( reference ) For the WebSocket endpoint, specify version=2 in the query parameters of the handshake request. ( reference ) Word and phoneme level timestamps are…
EVI API improvements
EVI version 4-mini is now available. This version enables the use of Octave 2 for TTS alongside a supplemental LLM of your choosing, bringing Octave 2’s multilingual capabilities to EVI. Specify "version": "4-mini" in your EVI config version to use it.
September 20255 releases
TTS API improvements, EVI API improvements
Responses from /v0/tts/stream/json now include a request_id field for easier tracking and debugging. EVI API improvements You can now change the voice within an active session by specifying a voice_id in a session settings message.
TTS API improvements
Responses from /v0/tts/stream/json now include a request_id field for easier tracking and debugging.
EVI API improvements
You can now change the voice within an active session by specifying a voice_id in a session settings message.
TTS API improvements
Introduced a TTS WebSocket endpoint that streams text in and speech out.
EVI API improvements
You can now change the voice within an active session by specifying a voice_id in a session settings message.
August 20255 releases
TTS API improvements
Introduced a TTS WebSocket endpoint that streams text in and speech out.
EVI API improvements
Fixed a bug where the voice_id query parameter on the /chat endpoint only accepted Voice Library voices. It now supports custom voices as well.
EVI API improvements
Added support for OpenAI’s GPT-5 , GPT-5-mini , and GPT-5-nano models as a supplemental LLM options.
EVI API changes, EVI API improvements
Added new voice_id query parameter to EVI /chat endpoint. The name or ID of the voice from the Voice Library to be used as the speaker for this EVI session. This will override the speaker set in the selected configuration. Removed editable context type for injected context. EVI…
EVI API changes
Added new voice_id query parameter to EVI /chat endpoint. The name or ID of the voice from the Voice Library to be used as the speaker for this EVI session. This will override the speaker set in the selected configuration. Removed editable context type for injected context.
July 20253 releases
EVI API improvements
New supplemental LLMs are now supported for all EVI versions: Claude Sonnet 4 (Anthropic) Llama 4 Maverick (SambaNova) Qwen3 32B (SambaNova) DeepSeek R1-Distill (Llama 3.3 70B Instruct, via SambaNova) Kimi K2 (Groq)
EVI API changes, EVI API improvements
EVI 3 is now available in the API. You can enable it by setting evi_version: "3" in your config. Refer to the Migration Guide if you’re upgrading from EVI 1 or 2. EVI 1 and 2 will be deprecated on August 30, 2025 , so be sure to migrate before then. A voice must be explicitly sp…
EVI API changes
EVI 3 is now available in the API. You can enable it by setting evi_version: "3" in your config. Refer to the Migration Guide if you’re upgrading from EVI 1 or 2. EVI 1 and 2 will be deprecated on August 30, 2025 , so be sure to migrate before then. A voice must be explicitly sp…
June 20253 releases
TTS API changes
Instant mode is now enabled by default for all streaming endpoints . The 10% surcharge for instant mode has been removed. It is now priced the same as standard streaming. Improved error message when making a TTS streaming request with instant mode enabled but without specifying…
TTS API additions
TTS responses now contain transcribed_text within each Snippet when instant_mode is not enabled.
EVI API additions
Added support for defining nudges in your EVI config, to help EVI naturally fill the silence during inactivity.
May 20251 release
EVI API additions
Added support for Google’s gemini-2.5-flash-preview-04-17 model as a supplemental LLM option
April 20254 releases
TTS API additions
Added instant_mode for ultra-low-latency streaming, which starts sending audio chunks immediately (first chunk in ~200 ms). Added strip_headers to remove per-chunk headers so that streamed audio can be concatenated into a single file.
TTS API additions, TTS API changes, EVI API additions
Added new TTS streaming endpoints for streaming audio output Added list voices and delete voice endpoints Added speed parameter for adjusting rate of speech Added trailing_silences for injecting pauses between utterances TTS API changes Improved audio fidelity for Octave TTS out…
TTS API additions
Added new TTS streaming endpoints for streaming audio output Added list voices and delete voice endpoints Added speed parameter for adjusting rate of speech Added trailing_silences for injecting pauses between utterances Improved audio fidelity for Octave TTS outputs by doubling…
EVI API additions
Added support for Anthropic’s claude-3-7-sonnet-latest model as a supplemental LLM option
November 20247 releases
EVI API changes
Ensured that when a custom_session_id is sent in the SessionSettings message, this custom session ID will be added to all returned payloads
EVI API additions, EVI API changes
Added support for Server-Sent Events (SSE) for Custom Language Models , an alternative approach that can reduce latency and simplify the development process EVI API changes Ensured that when a custom_session_id is sent in the SessionSettings message, this custom session ID will…
EVI API additions
Added support for Server-Sent Events (SSE) for Custom Language Models , an alternative approach that can reduce latency and simplify the development process EVI API changes Ensured that when a custom_session_id is sent in the SessionSettings message, this custom session ID will…
EVI API changes
Deprecated support for claude-instant-1.2 (any existing integrations should migrate to current models like claude-3.5-haiku-latest )
EVI API additions, EVI API changes
Added support for Anthropic’s claude-3.5-haiku-latest model as a supplemental LLM option Added support for OpenAI’s gpt-4-turbo model Introduced {{now}} default dynamic variable for system prompts, which is replaced with the current UTC timestamp and does not require sending a v…
EVI API additions
Added support for Anthropic’s claude-3.5-haiku-latest model as a supplemental LLM option Added support for OpenAI’s gpt-4-turbo model Introduced {{now}} default dynamic variable for system prompts, which is replaced with the current UTC timestamp and does not require sending a v…
Bugs bashed
Fixed audio reconstruction errors that affected some chat recordings Prevented some EVI errors by dropping any empty assistant messages Enhanced audio quality in reconstructed audio by removing unnecessary WAV headers, eliminating clicking artifacts
October 20246 releases
EVI API additions
Added support for claude-3.5-sonnet-latest (currently points to claude-3.5-sonnet-20241022 ) and made this model the recommended supplemental LLM Added support for tool use with Gemini models ( gemini-1.5-pro and gemini-1.5-flash ) Bugs bashed Fixed a bug where context was incor…
Bugs bashed
Fixed audio reconstruction errors that affected some chat recordings Prevented some EVI errors by dropping any empty assistant messages Enhanced audio quality in reconstructed audio by removing unnecessary WAV headers, eliminating clicking artifacts
EVI API changes
Added a more informative error message for when Google Gemini models are overloaded, returning an E0718 error code instead of silently dropping the connection
EVI API additions, EVI API changes
Added a new base voice, Sunny , featuring a male voice with an Indian accent Improved the reliability of the experimental custom voice creation feature by reducing hallucinations, and added 11 new adjustable parameters - articulation , buoyancy , enthusiasm , nasality , smoothne…
EVI API additions
Added a new base voice, Sunny , featuring a male voice with an Indian accent Improved the reliability of the experimental custom voice creation feature by reducing hallucinations, and added 11 new adjustable parameters - articulation , buoyancy , enthusiasm , nasality , smoothne…
Bugs bashed
Fixed a bug where context was incorrectly set as persistent and added to every user messages, despite being specified as type: temporary
September 20248 releases
EVI API changes
Upgraded gemini-1.5-pro and gemini-1.5-flash models to use the latest versions, gemini-1.5-pro-002 and gemini-1.5-flash-002 Improved audio quality for EVI phone calling Bugs bashed Fixed an issue with the EVI WebSocket auto-reconnecting after timeouts, by updating the inactivity…
Bugs bashed
Fixed an issue with the EVI WebSocket auto-reconnecting after timeouts, by updating the inactivity timeout socket close code from 1001 to 1000 Fixed a bug where the GET /chat_groups/{id} endpoint would return all chats, not just the chats in the chat_group
EVI API changes
Added support for resuming chats with supplemental LLMs for EVI 2 Updated the DACHER base voice, making it significantly higher quality and more reliable Improved EVI’s ability to recover from accidental interruptions. Previously, if EVI was interrupted by non-speech sounds, EVI…
Bugs bashed
Fixed an issue where @ signs would be removed in emails, leading to incorrect pronunciation; now they will be replaced with “at” and pronounced correctly Fixed a bug with numbered lists, leading to lists being split into new lines and spoken incorrectly
EVI API changes
Improved text validation permissiveness for config names and descriptions, allowing a wider range of printable characters Added a new error code (E0720) to handle scenarios where data retention is off so chat group history is unavailable, providing a more informative error messa…
EVI API additions, EVI API changes
Released the EVI 2 API, with major improvements to the core EVI experience. Developers can try it now: EVI 2 docs Introduced an experimental feature for creating custom voices through adjustable sliders: Custom voices EVI API changes Improved text validation permissiveness for c…
EVI API additions
Released the EVI 2 API, with major improvements to the core EVI experience. Developers can try it now: EVI 2 docs Introduced an experimental feature for creating custom voices through adjustable sliders: Custom voices EVI API changes Improved text validation permissiveness for c…
Bugs bashed
Fixed an issue to ensure chat_id is passed to users when using custom language models and phone calling together, enabling developers to retrieve post-call details with these features Fixed a bug where resumed chat groups would use the first rather than the most recent config in…
August 20241 release
EVI API changes
Enabled resuming previous chats with a new config. Previously, it was not possible to resume chats in a chat group with different configs. This change allows developers to change the prompt, voice, and other options in their config, while still retaining the context in their cha…
Shipping cadence
Releases per month over the last 12 months. Busiest month: November 2025, 3 releases.
What Hume AI ships
Releases in the last 12 months by category and product.
By category
- API8
By product
- EVI API3
- TTS API3
- TTS API, EVI API2
Hume AI updates FAQ
When did Hume AI last ship an update?
The most recent Hume AI update we track is “TTS and EVI API sunset notice”, released on October 2, 2026.
What did Hume AI release in October 2026?
Hume AI shipped 1 update in October 2026, including “TTS and EVI API sunset notice”.
How often does Hume AI release updates?
We tracked 8 updates from Hume AI in the last 12 months, about one every 18 months. The busiest month was November 2025, with 3 releases.
Where is Hume AI's official changelog?
Hume AI publishes release notes on Hume API Changelog, linked at the top of this page. Every entry here links back to the official page it came from.
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