Hi Team, Question: how do you make a Realtime agent speak a configured greeting verbatim at the start of a phone call? Setup: -

@livekit/agents@1.4.2

,

@livekit/agents-plugin-openai@1.4.2

- Single

voice.AgentSession({ llm: new openai.realtime.RealtimeModel({ model: 'gpt-realtime', voice: 'marin', ... }) })

— no separate STT/TTS (Realtime model is the whole pipeline) - SIP inbound calls via LiveKit - Each company has a configured first-line greeting (e.g.

"Hi, thank you for calling Chucky Cheese, this is Tony — you are on a recorded line. How can I help?"

) that we need spoken verbatim when the call connects, before any user input. What I've tried: 1.

session.say(greeting, { allowInterruptions: true })

→ throws

"trying to generate speech from text without a TTS model"

because we don't configure a separate TTS pipeline (the realtime model owns audio). 2.

session.generateReply({ instructions: greeting })

→ the model hallucinates a different greeting (e.g. says "Welcome to fun zone" for the Chucky Cheese prompt).

instructions

is a system-prompt-style directive for the turn, not text to speak. 3.

session.generateReply({ instructions: "With an upbeat tone, immediately say "${greeting}". Do not say it multiple times." })

→ mostly works, but the model occasionally leaks fragments of the wrapper meta-text (e.g. callers hear "with an upbeat attitude…" before the actual greeting). Security/UX issue for us since we're customer-facing. Is there a canonical pattern for "Realtime agent speaks this exact text first, then proceeds normally"? I've thought about: - Pre-populating the

Agent.chatCtx

with a synthetic

ChatMessage({ role: 'assistant', content: greeting })

and then calling

session.generateReply()

with no args — but I'm not sure the realtime model will actually speak a context-only item. - Mounting a separate

tts:

on the session purely so

session.say()

works — feels wasteful since the realtime model already does audio. - Adding

voice.Agent.onEnter()

override — but unclear what the right hook is for "speak this verbatim." Is there a method on

voice.AgentSession

or

realtime.RealtimeModel

I'm missing for "play this exact text through the realtime model's audio" without going through the LLM-instruction path? Pointers to a sample repo would be great.

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