Instant ack
An instant ack is the immediate acknowledgment the agent sends when a user message arrives but the substantive reply will take longer than a few seconds. A short 'looking that up...' or 'on it...' message keeps the user from wondering if the agent received their request.
Why it matters
Multi-step agent turns can take 5-30 seconds when the agent has to call several tools in sequence. The user texted; nothing has happened in 4 seconds; they wonder if the agent got the message. The instant ack is the patch.
The pattern: when the agent receives a message that will need substantive work, it immediately sends a short acknowledgment ("on it," "looking up your calendar," "asking Stripe about that payment"). The full reply comes when the work is done; the ack covers the gap.
The honest constraints:
- The ack should be honest. "On it" works because it does not promise a specific outcome. "I'll send the invoice" before checking would be wrong; if the invoice fails, the user has been promised something that did not happen.
- Channel-dependent. SMS allows multiple messages; an ack-then-result pattern is fine. Voice has different latency expectations; the ack pattern needs to account for the conversational flow.
- Don't overdo it. If every message gets an ack-then-result, the user feels they are being talked to twice. The pattern is for the cases where work-time would otherwise be a confusing silence.
How Ajeris handles this
Ajeris's agent loop decides per-turn whether an instant ack is appropriate. Quick turns (seconds) skip the ack; the response itself arrives in time. Slow turns (multi-tool, long reasoning) get an ack within ~500ms acknowledging receipt; the substantive reply follows.
For voice calls, the ack is verbal: a short "let me check that" with a brief filler beat while the tool call completes. For SMS, the ack is a short text message with the result following.
