This incident is resolved. Speech delivery has been normal since 7:51 AM PT (14:51 UTC).
Summary: Between 7:30 and 7:51 AM PT on July 31, an upstream text-to-speech provider experienced elevated latency. On affected calls (~7% during the window), the AI agent's responses were generated correctly but the audio was not delivered, so callers heard silence and calls ended in a silence timeout. Transcripts for affected calls may be missing agent responses.
The provider restored performance by adding server capacity, and we are following up with them on production SLOs. Our automatic failover to a backup voice provider did not engage during the degradation; we identified and fixed the defect in its latency detection, which will be deployed to production shortly. We apologize for the disruption to your calls.
Resolved
This incident is resolved. Speech delivery has been normal since 7:51 AM PT (14:51 UTC).
Summary: Between 7:30 and 7:51 AM PT on July 31, an upstream text-to-speech provider experienced elevated latency. On affected calls (~7% during the window), the AI agent's responses were generated correctly but the audio was not delivered, so callers heard silence and calls ended in a silence timeout. Transcripts for affected calls may be missing agent responses.
The provider restored performance by adding server capacity, and we are following up with them on production SLOs. Our automatic failover to a backup voice provider did not engage during the degradation; we identified and fixed the defect in its latency detection, which will be deployed to production shortly. We apologize for the disruption to your calls.
Monitoring
We identified the cause as elevated response latency at an upstream text-to-speech provider, detected from 7:30 AM PT (14:30 UTC). The agent generated correct responses on every turn, but the speech audio was not delivered to the caller in time. Roughly 7% of calls during the window were affected. The provider has added server capacity and restored normal performance — call success rates returned to baseline as of 7:51 AM PT, and the issue was fully mitigated by 8:00 AM PT. Our QA and Engineering teams are continuing to monitor closely.
Investigating
We are investigating reports of calls where the AI agent stops responding after the caller's first turn, with the call ending in a silence timeout. Callers on affected calls may hear the greeting and then silence. Both inbound and outbound calls can be affected.
