AsyncAPI channel · Hume AI
· Hume AI WebSocket APIs
/chat
Real-time EVI chat. Client sends audio and control messages; server
streams transcripts, assistant text, synthesized audio and tool events.
Connection URL: `wss://api.hume.ai/v0/evi/chat`.
Provider:Hume AIAsyncAPI: v2.6.0Spec: Hume AI WebSocket APIsOperations: 2Messages: 17
Channel address
/chat
Operations
publish
eviChatSend
Messages the client sends to EVI.
subscribe
eviChatReceive
Messages EVI streams back to the client.
Messages
audio_input
Base64-encoded audio chunk treated as user speech.
Content-Type:
session_settings
Configure session-level parameters such as audio encoding, context, language model, tools and variables.
Content-Type:
user_input
Plain text inserted into the conversation as the user.
Content-Type:
assistant_input
Plain text the assistant should synthesize and speak.
Content-Type:
tool_response
Successful response to a tool call.
Content-Type:
tool_error
Error response to a tool call.
Content-Type:
pause_assistant_message
Pause assistant responses while still recording user audio.
Content-Type:
resume_assistant_message
Resume assistant responses after a pause.
Content-Type:
chat_metadata
Sent once at the start of a connection with chat and chat-group identifiers.
Content-Type:
user_message
Transcript and prosody scores for a user utterance.
Content-Type:
assistant_message
A piece of generated assistant text returned by the language model.
Content-Type:
assistant_prosody
Predicted expression scores for an assistant utterance.
Content-Type:
audio_output
Base64-encoded chunk of synthesized assistant audio.
Content-Type:
assistant_end
Marks the end of an assistant turn.
Content-Type:
user_interruption
Signals that the user started speaking and EVI interrupted itself.
Content-Type:
tool_call
Request from EVI to invoke a registered tool.
Content-Type:
error
WebSocket-level error emitted by the EVI server.
Content-Type:
About AsyncAPI
The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.