Understanding the Flux State Machine
Traditional STT+VAD requires you to build complex interruption logic. Flux handles this natively.
Emitted events adhere to the below state machine for managing turns:
Update
messages are sent for approximately every 0.25 seconds of transcribed audio, regardless of transcript updates, unless a state change has occurred.- An
EagerEndOfTurn
message always contains a nonempty transcript. - A
TurnResumed
message can only follow a precedingEagerEndOfTurn
message. - The
EndOfTurn
transcript will always match the immediately precedingEagerEndOfTurn
transcript. If the transcript changes after anEagerEndOfTurn
, aTurnResumed
event will occur first. - The
turn_index
increments immediately following anEndOfTurn
message.
Configuring Event Behavior: The EagerEndOfTurn
and TurnResumed
events are only triggered when you set the eager_eot_threshold
parameter. The EndOfTurn
event behavior is controlled by eot_threshold
and eot_timeout_ms
parameters. See the End-of-Turn Configuration for details on tuning these thresholds for your use case.
Turn Lifecycle Example
Here’s how Flux processes a customer calling support saying “Hi I need to cancel my subscription please.”
Notice how confidence builds up and how the EagerEndOfTurn
event fires before the final EndOfTurn
. With EagerEndOfTurn
, your voice agent can begin preparing a response before the user has fully finished speaking. This allows you to send a synchronous request with early context, creating the effect of a faster, more natural reply.