I wanted to share a project I’ve been working on called Convoxa. It’s a native iOS transcriber/summarizer. I had two main goals: keep it efficient and keep it private.
THE TECH STACK
100% Swift & SwiftUI: No heavy cross-platform wrappers or bloated dependencies.
Binary Size: The final build is only 4.8 MB.
Transcription: Uses Apple's latest speech APIs for maximum privacy and efficiency.
THE CHALLENGE: BYPASSING THE 4K CONTEXT LIMIT
The biggest technical hurdle was working with Apple’s foundation models. The default context window is capped at 4096 tokens, which is practically useless for anything over a 10-minute meeting transcript.
I ended up building a recursive chunking method to "feed" the model long-form data without losing the global context of the conversation. I use a sliding window approach where each chunk's summary informs the next, ensuring the final output doesn't "hallucinate" at the seams where the chunks meet. It’s now stable enough for long-form audio while remaining entirely on-device for supported hardware.
PRIVACY & AI MODES
On-Device: (Apple Intelligence required) - Total local processing.
Cloud: With reasoning for intelligent insights (Zero Data Retention).
I’m currently in the pre-order phase (out on Feb 3rd) and would love to get some feedback from this community on the performance and the chunking logic.
App Store: https://apps.apple.com/us/app/convoxa-ai-meeting-minutes/id6...