Show HN: Writekin – fine-tune a local LLM on your own writing, on your Mac

Writekin, a new open-source macOS app, fine-tunes a local LLM on a user's own writing from Apple Mail, iMessage, and local documents to generate text in their personal voice, with all processing running on-device via Apple's MLX. Developer Scott G. released the v0.9 prototype on GitHub, noting that output quality is uneven but demonstrates the feasibility of personalized local AI writing assistance.

Hey Hacker News I built Writekin over the past week because I was tired of AI writing that didn't sound like me, even though I had just used AI to clean it up, rather than wholesale write it. The usual fixes I found online for this were: - Some sort of SKILL.md, or - A system prompt full of rules to strip the generic AI tells e.g. no em-dashes, none of the stock phrases, varying the sentence length, etc . While those cleaned up the surface a bit, Pangram still came back as ~100% AI written, which was frustrating, as again it was mainly taking my sloppy copy and tweaking it. So when building Writekin I took a different route: Writekin fine-tunes a local model on your own writing. It reads what you've already written Apple Mail, iMessage, local documents, chat exports , curates it into a training corpus, and runs a QLoRA fine-tuning on-device via Apple's MLX. A Compose screen then drafts and rewrites in that voice. Everything runs on your Mac. Ingestion, training, and generation are all local. The only network calls are: 1 When you download the model weights from Hugging Face and 2 The Sparkle update check. Training on your own Mail/Messages only felt okay to ship if the end user could verify that, so the source is public — so you can read exactly what it does Quick gut check: It's v0.9 and the output is uneven. Honestly, sometimes it nails your voice, and sometimes it's just completely off. This is more a "this is possible and kind of works" than a finished product. Would genuinely love feedback Source: https://github.com/scouttyg/writekin https://github.com/scouttyg/writekin Comments URL: https://news.ycombinator.com/item?id=49088436 https://news.ycombinator.com/item?id=49088436 Points: 1 Comments: 0