I notice on the warm transfer task there is a noticeable lag before it starts talking to the transferee - is there something we can do to speak up on_enter for that task

Thanks for reaching out, Arthur. I'm an AI assistant and I'm here to help. Give me a moment while I research this topic.

we are using the WarmTransferTask out of the box - its almost as if it is waiting on the tranferee to talk before it gives a summary and connects the caller

Thanks — I appreciate the extra detail. You're using the WarmTransferTask out of the box and seeing it wait for the transferee to speak before it gives the summary and connects the caller. I hear you and that delay can feel awkward for callers and transferees. What’s happening • The WarmTransferTask is designed to wait for the transferee to acknowledge the call (for example, by speaking) before it reads the summary and offers connection options. That wait-for-response behavior is intentional — it ensures the transferee is present before sensitive context is shared. • The WarmTransferTask is a prebuilt/closed task and does not expose an

on_enter

hook or a configuration option to force immediate speech on answer. You cannot directly change that internal behavior. What you can do right now (options) • Shorten the spoken summary in the task parameters: If you pass any

extra_instructions

or similar text that the task reads, make that text very short so the first audible content is briefer once it begins. • Pre-speak before handing to the prebuilt task: Play a short prompt (for example, “Connecting you now…”) immediately before invoking the WarmTransferTask so the transferee hears something while the task completes its dial/connect checks. • Build a custom warm-transfer task for immediate speech: If you need deterministic control (speak as soon as the transferee answers), implement a custom task that: a. Dials the transferee (using the same dialing APIs the WarmTransferTask uses). b. Plays hold audio to the caller. c. Uses

on_enter

and

session.say()

or your TTS pipeline to speak the summary immediately upon answer rather than waiting for transferee input. d. Presents actions (connect, decline, voicemail detection) and then merges if the transferee accepts. This approach gives you full control over timing, wording, and behavior. The WarmTransferTask cannot be configured to do this for you. Questions to help me recommend the best next step 1. Are you currently passing any

extra_instructions

or custom text into the WarmTransferTask? If so, can you share the length/content (I can suggest a concise version). 2. Is the transferee always human (live agent) or could it hit voicemail/automated systems? That affects whether you should wait for speech or detect answer-tone/voicemail. 3. Would you prefer a short-term tweak (shorten wording or pre-prompt) or a longer-term route (we outline a custom task implementation for immediate speech)? If you want, I can: • Suggest concise wording for the summary so the audible portion is shorter. • Outline the minimal custom task flow and the API calls you’d need to recreate warm-transfer behavior with immediate

on_enter

speech. Tell me which option you prefer and provide any

extra_instructions

you’re using (if applicable) — I’ll draft the exact changes or the custom-task outline. Sources: WarmTransferTask | LiveKit Documentation

Sorry by the transferee I mean the person being transferred too when the caller wants to talk to a human, we call outwards and that outwards call takes 15 seconds to start speaking

Thanks — that clarification helps a lot. I understand now you mean the outbound call to the transferee (the person you’re transferring to) takes about 15 seconds to start speaking, and you want that delay reduced so the transferee hears something sooner. Why this is happening • The prebuilt WarmTransferTask intentionally waits for the transferee to acknowledge the call before reading the summary. That plus any dialing/connect latency (SIP/telephony network, answer detection, TTS/media startup) can produce the ~15s gap you’re seeing. • The WarmTransferTask is a closed prebuilt flow and doesn’t expose an

on_enter

override to force immediate speech on answer. Practical options you can use right away • Shorten what the task reads: If the task is reading a long summary, reduce it to a one-line prompt so the audible portion is shorter once it starts. • Play a quick pre-prompt before invoking the WarmTransferTask: Send a short phrase like “Hi — connecting you now” right before you dial the transferee so they hear something while the transfer flow completes. • Pre-warm TTS and media paths: Initialize your TTS and media streaming earlier in the call (if possible) so the first generated audio has less cold-start latency. • Detect answer faster: If you can rely on answer-detection signals (SIP 200 or similar) rather than waiting for speech, you can trigger your immediate prompt on answer event. This requires a custom handling approach rather than the prebuilt task. • Build a custom warm transfer task (recommended if you need deterministic immediate speech): Implement a small custom task that: a. Dials the transferee (same dialing mechanism the prebuilt task uses). b. Plays hold audio to the original caller. c. Uses

on_enter

and

session.say()

(or your TTS) to speak the summary immediately once the dialer reports answer, without waiting for the transferee to speak. d. Presents connect/decline actions and then merges on acceptance. This gives you control over exactly when the first audio plays and can eliminate the 15s silence. A few quick diagnostic questions to narrow down the root cause 1. Is the 15s delay always present, or only sometimes? If intermittent, that points to network/SIP variability. 2. Are you seeing any signaling events (SIP 200, early media) that indicate when the remote side answers? If you can access answer events, we can use them to trigger immediate speech. 3. Is the outbound call going to a human agent's SIP phone, a mobile number, or to an IVR/voicemail system? Voicemail/IVR behavior often adds delay. 4. Do you have control of the system that initiates the outbound dial (so you could insert a pre-prompt or pre-warm TTS)? If you want, I can: • Suggest a concise one-line summary you can pass into the task to reduce audible time. • Outline the minimal custom task flow and the specific calls/events to use so speech starts on answer. • Help interpret signaling logs if you can share the answer/time events (rough timestamps are fine). Tell me which path you’d like to try (quick wording tweak, pre-prompt, or custom task) and answer any of the diagnostic questions you can — I’ll give the exact next steps.

The outbound call always pauses until someone replies and then it takes 5 seconds to speak

Thanks — that helps. You’re saying the outbound transfer always pauses until the transferee speaks, and then after they reply there’s another ~5s before the agent speaks. I hear the frustration — that gap can make transfers feel slow and awkward. What’s causing the pause • The prebuilt WarmTransferTask is designed to wait for the transferee to acknowledge the call before reading the summary. That explains the initial pause until they speak. • The additional ~5s after the transferee replies sounds like media/TTS or answer-detection latency (TTS generation, audio pipeline warm-up, or the task waiting to confirm the transferee’s speech). Practical actions you can take right now • Short-term: Insert a short pre-prompt before invoking the WarmTransferTask so the transferee hears something immediately (e.g., “Connecting you now.”). This masks the silence while the task completes dialing and checks. • Shorten spoken summary: Make the first spoken content as brief as possible so when the task does speak it happens quickly and is less noticeable. • Pre-warm TTS/media: If you control the TTS pipeline, initialize or generate the first audio earlier in the flow so the TTS/media path is warmed up by the time the transferee is ready to hear it. • Use answer-detection to trigger speech: If you can detect the remote-side answer event (SIP 200, early-media or similar), trigger your first prompt on that event instead of waiting for transferee speech. This requires custom handling rather than the prebuilt task. • Long-term: Implement a custom warm-transfer task that: a. Dials the transferee. b. Plays hold audio to the caller. c. Uses

on_enter

and

session.say()

(or your TTS) to immediately speak upon remote answer. d. Presents connect/decline actions and merges on acceptance. This gives deterministic control and eliminates the built-in wait-for-response behavior. A couple quick diagnostics that will help me target the fix 1. Is the ~5s delay after the transferee replies consistent every time? 2. Where is your TTS generated (your service vs. LiveKit TTS)? If it’s external, cold-start there is a likely cause. 3. Can you access signaling events (answer/early media) for outbound calls? If yes, we can trigger speech on the answer event. 4. Are you able to add a pre-prompt before handing off to WarmTransferTask (i.e., do you control the flow that starts the task)? What I can do next • If you want a quick tweak, share any

extra_instructions

or the exact wording the WarmTransferTask uses and I’ll suggest a concise version or a short pre-prompt. • If you want to remove the wait, I can outline the minimal custom task flow and the specific events/APIs to use to start speech immediately on answer. Tell me which approach you prefer and answer any of the diagnostic questions you can — I’ll give exact steps to implement it.

I think the issue is that the person picking up the call gets a silence and usually they expect the AI to talk first to say

Hello, this is the AI agent for Bla with a customer wanting to transfer - are you free to take the call

. There is no way to tune this so I assume we need to build a manual task for now?

You’re right to call that out — thanks for the clear example of the expected behavior. I confirm: the prebuilt WarmTransferTask cannot be tuned to speak first on answer. It intentionally waits for the transferee to acknowledge before reading context, so it will produce the silence you’re seeing. If you need the AI to immediately introduce itself (e.g., “Hello, this is the AI agent for Bla… are you free to take the call?”) you’ll need a custom/manual warm-transfer task. If you want, I can help you build that custom task. Here’s a concise plan and the choices you’ll need to make: 1) Minimal custom warm-transfer flow (what it does) 1. Dial the transferee (use the same outbound dial/SIP call mechanism you already use). 2. Play hold music or a hold message to the original caller while dialing. 3. On remote answer event, immediately run

on_enter

logic to: ◦ Play the AI intro via

session.say()

or your TTS pipeline. ◦ Offer short options (connect/decline) and listen for DTMF, voice reply, or a simple confirmation phrase. 1. If transferee accepts, call the connect/merge API to join the parties. If declines or voicemail, follow your fallback (voicemail, retry, notify caller). 2) Key implementation details I’ll help you with • How to detect remote answer events (SIP 200 / answer callbacks or early-media depending on telco). • How to pre-warm or generate the first TTS utterance so there’s minimal generation latency. • Exact sequence/code snippets to call the dial API, play hold audio, invoke

session.say()

on answer, and merge calls. • Handling voicemail/IVR detection so you don’t play sensitive context to an automated system. 3) Tradeoffs and recommendations • Short-term: If building a custom task is heavy, you can mask the delay by playing a short pre-prompt to the transferee before the task takes over; this is a workaround but not deterministic. • Best long-term: Custom task gives deterministic immediate speech, full control of timing and wording, and robust handling for voicemail/IVR. Next steps — tell me which you want • If you want the quick workaround, I’ll suggest a short intro prompt you can insert immediately before dialing. • If you want the custom task, tell me: ◦ Which signaling/events you can access (SIP callbacks, webhook on answer). ◦ Whether you use LiveKit TTS or an external TTS (so I can show how to pre-warm). ◦ Whether you prefer voice confirmation or DTMF for accept/decline. Pick an option and share those details (or say “just build the custom task” if you want me to outline full code/sequence) — I’ll draft the exact steps and snippets to implement it.

the WarmTransferTask works for us - we just want to fork this Task and add an immediate on_enter trigger to speak first.

Great — forking the WarmTransferTask and adding an immediate

on_enter

trigger is the right approach if you want the AI to introduce itself immediately on answer while keeping the rest of the warm-transfer behavior. I can walk you through a minimal plan and concrete next steps. First, a couple quick clarifying questions so I tailor the guidance and code snippets to your setup: 1. Which SDK / language are you using for agents/tasks? (JavaScript/TypeScript, Python, or another runtime.) 2. Do you already have access to the WarmTransferTask source in your codebase (i.e., are you able to copy/extend the prebuilt task), or do you need guidance on where to obtain the task implementation to fork? 3. Where is your TTS coming from — LiveKit-managed TTS or an external TTS provider? Do you need help pre-warming TTS? 4. How do you detect the remote-side answer event in your current flow (webhook, SIP 200 callback, SDK event)? This affects when to run

on_enter

. 5. Do you want the immediate intro to be a short TTS phrase followed by waiting for the transferee’s response, or do you want it to both announce and offer simple DTMF/voice options right away? What I’ll provide once you answer: • A concise code template showing how to fork/extend WarmTransferTask and implement an

on_enter

that: a. Runs as soon as the outbound call is answered (using your answer event). b. Immediately invokes

session.say()

or plays pre-generated TTS so the transferee hears the AI intro without waiting to speak first. c. Keeps the rest of WarmTransferTask behavior (summary, connect/decline tools, voicemail detection). • Guidance on pre-warming TTS/Media to avoid the extra seconds of cold-start latency. • Advice for safely handling voicemail/IVR detection so you don’t play sensitive customer context to an automated endpoint. • Optional: a short default intro script you can use ("Hello — this is the AI agent for Bla with a customer who would like a transfer. Are you free to take the call?") and a concise fallback for voicemail. If you prefer, say which language/runtime and I’ll draft the forked-task example and the exact calls (including sample

on_enter

) you can drop into your code.