Send Message | Hume API

X-Hume-Api-Key
API Key authentication via header

This endpoint expects an object.

SessionSettings object Required

Settings for this chat session. Session settings are temporary and apply only to the current Chat session.

These settings can be adjusted dynamically based on the requirements of each session to ensure optimal performance and user experience. See our Session Settings Guide for a complete list of configurable settings.

UserInput object Required

User text to insert into the conversation. Text sent through a User Input message is treated as the user’s speech to EVI. EVI processes this input and provides a corresponding response.

Expression measurement results are not available for User Input messages, as the prosody model relies on audio input and cannot process text alone.

AssistantInput object Required

Assistant text to synthesize into spoken audio and insert into the conversation. EVI uses this text to generate spoken audio using our proprietary expressive text-to-speech model.

Our model adds appropriate emotional inflections and tones to the text based on the user’s expressions and the context of the conversation. The synthesized audio is streamed back to the user as an Assistant Message.

ToolResponseMessage object Required

Return value of the tool call. Contains the output generated by the tool to pass back to EVI. Upon receiving a Tool Call message and successfully invoking the function, this message is sent to convey the result of the function call back to EVI.

For built-in tools implemented on the server, you will receive this message type rather than a ToolCallMessage. See our Tool Use Guide for further details.

ToolErrorMessage object Required

Error message from the tool call, not exposed to the LLM or user. Upon receiving a Tool Call message and failing to invoke the function, this message is sent to notify EVI of the tool’s failure.

For built-in tools implemented on the server, you will receive this message type rather than a ToolCallMessage if the tool fails. See our Tool Use Guide for further details.

PauseAssistantMessage object Required

Pause responses from EVI. Chat history is still saved and sent after resuming.
When paused, EVI won’t respond, but transcriptions of your audio inputs will still be recorded. See our Pause Response Guide for further details.

ResumeAssistantMessage object Required

Resume responses from EVI. Chat history sent while paused will now be sent.

Upon resuming, if any audio input was sent during the pause, EVI will retain context from all messages sent but only respond to the last user message. See our Pause Response Guide for further details.

Successful Response