> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://dev.hume.ai/voice/reference/speech-to-speech-evi/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://dev.hume.ai/_mcp/server. # Speech-to-speech (EVI) > **Warning** > > **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. To compare > alternative voice models, see [Real World VoiceEQ](https://www.hume.ai/rw-voice-eq). For questions, contact > [Hume support](/support) or email [assist@hume.ai](mailto:assist@hume.ai). The EVI API provides a WebSocket endpoint for real-time voice conversations and REST endpoints for managing configs, prompts, tools, and chat history. ## API Docs - Speech-to-speech (EVI) [Chat](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chat.md) - Speech-to-speech (EVI) > Control Plane [Control Plane](https://dev.hume.ai/voice/reference/speech-to-speech-evi/control-plane/chat-chat-id-connect.md) - Speech-to-speech (EVI) > Control Plane [Send Message](https://dev.hume.ai/voice/reference/speech-to-speech-evi/control-plane/send.md) - Speech-to-speech (EVI) > Configs [Create config](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/create-config.md) - Speech-to-speech (EVI) > Configs [List configs](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/list-configs.md) - Speech-to-speech (EVI) > Configs [List config versions](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/list-config-versions.md) - Speech-to-speech (EVI) > Configs [Get config version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/get-config-version.md) - Speech-to-speech (EVI) > Configs [Create config version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/create-config-version.md) - Speech-to-speech (EVI) > Configs [Update config name](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/update-config-name.md) - Speech-to-speech (EVI) > Configs [Update config description](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/update-config-description.md) - Speech-to-speech (EVI) > Configs [Delete config](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/delete-config.md) - Speech-to-speech (EVI) > Configs [Delete config version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/configs/delete-config-version.md) - Speech-to-speech (EVI) > Prompts [Create prompt](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/create-prompt.md) - Speech-to-speech (EVI) > Prompts [List prompts](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/list-prompts.md) - Speech-to-speech (EVI) > Prompts [List prompt versions](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/list-prompt-versions.md) - Speech-to-speech (EVI) > Prompts [Get prompt version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/get-prompt-version.md) - Speech-to-speech (EVI) > Prompts [Create prompt version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/create-prompt-version.md) - Speech-to-speech (EVI) > Prompts [Update prompt name](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/update-prompt-name.md) - Speech-to-speech (EVI) > Prompts [Update prompt description](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/update-prompt-description.md) - Speech-to-speech (EVI) > Prompts [Delete prompt](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/delete-prompt.md) - Speech-to-speech (EVI) > Prompts [Delete prompt version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/prompts/delete-prompt-version.md) - Speech-to-speech (EVI) > Tools [Create tool](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/create-tool.md) - Speech-to-speech (EVI) > Tools [List tools](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/list-tools.md) - Speech-to-speech (EVI) > Tools [List tool versions](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/list-tool-versions.md) - Speech-to-speech (EVI) > Tools [Get tool version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/get-tool-version.md) - Speech-to-speech (EVI) > Tools [Create tool version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/create-tool-version.md) - Speech-to-speech (EVI) > Tools [Update tool name](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/update-tool-name.md) - Speech-to-speech (EVI) > Tools [Update tool description](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/update-tool-description.md) - Speech-to-speech (EVI) > Tools [Delete tool](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/delete-tool.md) - Speech-to-speech (EVI) > Tools [Delete tool version](https://dev.hume.ai/voice/reference/speech-to-speech-evi/tools/delete-tool-version.md) - Speech-to-speech (EVI) > Chats [List chats](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chats/list-chats.md) - Speech-to-speech (EVI) > Chats [List chat events](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chats/list-chat-events.md) - Speech-to-speech (EVI) > Chats [Get chat audio](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chats/get-audio.md) - Speech-to-speech (EVI) > Chat Groups [List chat_groups](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chat-groups/list-chat-groups.md) - Speech-to-speech (EVI) > Chat Groups [Get chat_group](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chat-groups/get-chat-group.md) - Speech-to-speech (EVI) > Chat Groups [Get chat group audio](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chat-groups/get-audio.md) - Speech-to-speech (EVI) > Chat Groups [List chat events from a specific chat_group](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chat-groups/list-chat-group-events.md) - Speech-to-speech (EVI) > Chat Webhooks [Chat Ended](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chat-webhooks/chat-ended.md) - Speech-to-speech (EVI) > Chat Webhooks [Chat Started](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chat-webhooks/chat-started.md) - Speech-to-speech (EVI) > Chat Webhooks [Tool Call](https://dev.hume.ai/voice/reference/speech-to-speech-evi/chat-webhooks/tool-call.md) ## OpenAPI Specification The raw OpenAPI 3.1 specification for this API is available at: - [OpenAPI JSON](https://dev.hume.ai/openapi.json) - [OpenAPI YAML](https://dev.hume.ai/openapi.yaml) ## AsyncAPI Specification The raw AsyncAPI 2.6.0 specification for the WebSocket channels is available at: - [AsyncAPI JSON](https://dev.hume.ai/asyncapi.json) - [AsyncAPI YAML](https://dev.hume.ai/asyncapi.yaml)