Use the Delay control panel to improve the user experience when a function takes longer than expected. Inserting transition utterances while a function is still processing prevents long silences and helps interactions feel more natural and responsive.

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Key benefits

  • Keep users engaged: Provide real-time feedback rather than leaving users waiting in silence.
  • Fully configurable timing: Control when and how often delay responses play.
  • Supports multiple utterances: Define a sequence of responses to use as interim messages.
  • Works across different function types: Available for global and flow functions (not supported on start or end functions).

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Important timing behavior

Delay timing does not begin from when the user stops speaking. It starts when the function begins executing — which can happen seconds later due to LLM, ASR, or model routing latency.

This means that if you set a delay of 1s, filler utterances may not begin until several seconds after silence, depending on system load and model timing.

When setting delays, consider the full turn latency — not just the time your function takes to respond. For LLM-heavy flows, use shorter delays like 0–0.5s or include immediate filler lines directly in the step prompt.

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How it works

  1. Define delay responses

    • Create a list of phrases the assistant can say while waiting for a function to complete.
    • These might include confirmations, status updates, or even sound effects like ‘keyboard typing.’

  2. Configure delay timing

    • Set the initial delay (in seconds) after function execution begins.
    • Define the interval between each subsequent utterance.

  3. Specify utterance length

    • For sound-based responses (e.g., typing noises), specify the expected duration to pace playback accurately.

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Example scenario

A restaurant booking function takes several seconds to confirm availability:

  1. The user asks for a table.
  2. The assistant immediately says: “Let me check availability for you.”
  3. After 0.5s, it plays: “Just a moment, I’m still checking…”
  4. After another 2s, it plays: “Thanks for waiting!”
  5. Once complete, the assistant returns: “Your table is booked!”

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Creating a new delay control phrase

  • Navigate to the Functions tab and select a function.
  • Open the Delay control panel.
  • Add one or more delay responses.
  • Set the initial delay and interval.
  • Optionally, specify the length of sound-based utterances.
  • Save changes and test in the chat panel to preview the delay behavior.

You can reference state variables inside delay responses using the $ symbol. For example: Still checking availability at $branch_name... The assistant will substitute the value automatically.

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Best practices

  • Keep filler utterances brief and natural — a mix of phrases like “Still working on it…” or “[typing]” helps maintain trust.
  • Avoid overly repetitive or robotic phrasing.
  • Use delay control sparingly: if your function is fast (under 1 second), it might not need filler responses at all.
  • For very slow flows, consider adding initial speech directly in the step prompt and letting the delay control handle the fallback.

This feature is ideal for API-based functions and LLM utility functions that experience irregular latency. It’s not suitable for conversational steps where the function is near-instant or where multiple branches could be chosen.

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Timeline diagram