A voice message arrives. You tap play, and the text is already underneath the

waveform. It feels like the app read your mind. Under the hood it is a small

queue with a few strict rules: transcribe what is new, never backfill history,

do one thing at a time, and fail without making noise.

That last rule is the one users notice most. Automatic transcription is a

background convenience, not a modal task. If the remote service is down, the

voice note simply stays untranscribed; the user can still swipe to try again.

No snackbar storm, no red banners, no “something went wrong” every few seconds.

This post walks through the design of the automatic queue in Folcadi, a

language-exchange messenger built with Flutter: why it only handles live

messages, how the fallback chain works, why the “transcribe my own voice

messages too” switch is separate, and how the on-device model downloads survive

navigation.

Automatic should mean “from now on”, not “all history”

The first product decision is the scope.…