One thing that s easy to overlook when building voice agents is what happens when a provider goes down or a model starts returning errors mid conversation.
In a normal API workflow, a failed request might mean retrying or showing an error. In a live voice call, it s different. The caller is waiting, and a failure in one component shouldn t bring down the entire conversation.
At Vaani AI @Vaani Developer Platform ,we ve been working on a multi-layer failover mechanism to handle this:
Independent fallback chains: Speech recognition, LLM and TTS each have their own backup providers.
Error-based switching: If the primary provider returns an error, the request moves to the next configured provider.
Safety-net fallback: Even when an agent is misconfigured, there s a fallback model available.
Configurable routing: Teams can choose primary and backup models, use their own API keys, and control whether fallback is enabled.
We noticed 70% of our replies come from the 2nd or 3rd message, but sending "Just bumping this to the top of your inbox" was getting us blocked.
We switched to sending a 30-second quick visual breakdown or a relevant free asset instead of a reminder. Replies went up without burning the relationship.
What s your go-to non-annoying follow-up angle that actually gets a response?
