Code
T7105 no-voice
A start of an agent was handed audio or speak, and the agent has no voice: the start is refused with the status 400, whoever starts it.
The fix
Give the agent a voice with a model that hears and one that speaks, or start it with a message alone.
TypeScript
export const helper = agent('helper', { model: writer, instructions: 'You help.', tools: [], limits: { steps: 12, perRun: { tokensOut: 50000 } }, voice: { hear: listener, speak: speaker } })