0.12.14 — Qwen3.8-27B in our own mixed-precision build

Released 2026-08-15 · full changelog · GitHub releases

Upgrade: pip install -U rapid-mlx · brew upgrade rapid-mlx · or grab the desktop app.

A Rapid-MLX mixed-precision quantization of Qwen3.8-27B that spends its bits where they matter, plus user-owned model aliases, the DeepSeek Harness agent, and the desktop app handing all updates to Sparkle.

Qwen3.8-27B, mixed-precision. rapid-mlx chat qwen3.8-27b-mixed-3.5bpw serves our own quantization of rapid-mlx/Qwen3.8-27B-mixed-3.5bpw-MLX — 13.0 GB of weights versus the 4-bit build’s 15.0 GB, spending bits where they matter instead of flattening every tensor to 4-bit. Measured through rapid-mlx serve on an M3 Ultra (8K prompt, peak across the process tree): 20 GB peak, 323 tok/s prefill, 40 tok/s decode, zero swap — plan for a 48 GB Mac or larger. Strong at code (10/10) and tool-calling (25/30, including parallel and sequential multi-tool), but 5/10 on the MATH subset with thinking off — which is why it is not a built-in RAM-tier default; for arithmetic-heavy work qwen3.6-35b-4bit or gemma-4-26b-4bit stay the safer picks (#1954). 172 text aliases, 221 total.
Name your own models. rapid-mlx alias set fast qwen3.5-4b-4bit gives any built-in model or Hugging Face repo id a name you choose, stored in your own config — no repo edit, no fork. Aliases can’t shadow a built-in name or chain to another user alias, and a malformed store fails closed rather than resolving to the wrong weights (#1942).
DeepSeek Harness joins the agents. rapid-mlx agents dsh --setup wires DeepSeek Harness to your local server like the Tier-1 agents, and rapid-mlx launch lists it. The agent test sweep now runs each agent inside a throwaway home, so it can no longer read or rewrite your real agent config (#1952).
Vision pixel bounds. --vision-min-pixels / --vision-max-pixels cap what a multimodal model’s image preprocessor produces, so a large photo can’t balloon the KV cache on a memory-tight Mac. Both default to off (#1943).
Desktop: Sparkle owns updates, end to end. The in-app DMG installer is gone; the app checks, downloads, verifies the signature, and installs through Sparkle. Builds from 0.12.12 onward keep themselves up to date; older builds are told to download once and never hit a broken in-app install path again (#1947). Qwen 3.8 models are recognized as their own family — correct picker name and tool-calling shown as a capability (#1959).
Fixes. /v1/models reports a hybrid model’s live metadata instead of a stale snapshot (#1955); a client disconnecting mid-stream no longer logs a false “missing finish” warning (#1951); rejected CORS preflights return the correct content length (#1949).

@guo — desktop app drops the in-app DMG installer, letting Sparkle own updates end to end (#1947)