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First response time

First response time (FRT) is the time from the first inbound customer message to the first human reply on a thread. It is one of the metrics your SLA policies track.

How it's calculated

FRT = time from the first inbound customer message to the first outbound human reply.

  • The clock starts on the first inbound customer message, not on thread creation. These differ when a thread is created programmatically before the customer sends anything.

  • Machine user and AI-generated replies do not stop the clock. Only a human agent's first reply ends the FRT measurement.

  • Threads created by a Plain user are excluded entirely.

  • For charting purposes, threads are grouped by when the first reply was sent, not when the thread was created.

Median and 90th percentile are quantile(0.5) and quantile(0.9) across all FRT values in the window.

Statistical views

Median: the midpoint FRT across all threads in the selected period. Half of threads got a first reply faster than this, half slower. Less skewed by outliers than the average.

90th percentile: 90% of threads received a first reply within this time. Use it to see how the slowest 10% of threads are performing.

Team member view

In Team reporting, FRT covers only threads where that team member sent the first reply.

SLA tracking

A thread breaches its FRT SLA if no human reply arrives before the configured deadline. See SLA compliance for how the breach rate is calculated.