Core AI is Apple's on-device ML runtime in iOS 27 / macOS 27 and the successor to Core ML: PyTorch models are exported with Apple's coreai-torch (LLMs: coreai.llm.export) into .aimodel bundles that run on the GPU or the Neural Engine, e.g. Qwen3-8B 4-bit decodes at 94 tok/s on an M4 Max GPU, MLX 90 under the same protocol (apple-silicon-llm-bench, macOS 27 beta, 2026-06).
This model has no row on DeviceMark, the on-device LLM leaderboard.
LFM2.5-8B-A1B — Core AI (the zoo's first MoE on iPhone)
Apple Core AI (.aimodel) conversion of LiquidAI/LFM2.5-8B-A1B:
a conv + full-attention MoE hybrid decoder (24 layers = 18 short-conv mixers + 6 GQA attention;
hidden 2048, vocab 128k; first 2 layers dense, the rest 32-expert top-4 sparse MoE). 8.3B total /
~1.5B active per token.
▶️ Run it (source) — the ChatDemo runner
(GUI + CLI, one app for every chat model in the catalog):
bash
1git clone https://github.com/john-rocky/coreai-kit
2open coreai-kit/Examples/ChatDemo/ChatDemo.xcodeproj
3# → Run, then pick "LFM2.5-8B-A1B (MoE)" in the model picker45# agents / headless (macOS):6cd coreai-kit/Examples/ChatDemo
7swift run chat-cli --model lfm2.5-8b-a1b --prompt "What can you do, offline?"
💻 Build with it — complete; the glue is kit API, copy-paste runs:
When Apple's FoundationModels built-in model isn't enough, keep your session code and swap the model — one line. CoreAIKit's KitLanguageModel plugs this bundle into the same system LanguageModelSession; your Tools, @Generable types and transcripts work unchanged, and capabilities (tool calling, guided generation) auto-detect per model.
The take-home is Examples/ChatDemo/Sources/QuickStart.swift
— this exact code as one typed function, no UI; the CLI is an argument shell over it, and
the GUI drives the same ChatSession across turns for its transcript.
Multi-turn? Hold the ChatSession and call respond(to:) per turn — it keeps the
conversation history; streamResponse(to:) yields tokens as they decode.
First run downloads the model — 9.0 GB (Mac) — then it loads from the
local cache (Application Support; progress via the downloadProgress callback)
Measure in Release — Debug is ~3× slower on per-token host work
The gather_qmm kernel
MoE decode normally reads all 32 experts' weights every token via the GatherMM composite even
though only the top-4 are routed — bandwidth-bound at 39 tok/s. This bundle uses a custom
coreai_torch.TorchMetalKernel that takes the routed indices as a kernel input and reads only the
4 routed experts' weight slabs → 3.6× faster (141 tok/s) at the same active-param bandwidth.
Bundles & honest quality
Shipped here (Mac-only):
dir
size
platform
decode tok/s
quality (fp32-oracle margin gate)
gpu-pipelined/lfm2_5_8b_a1b_decode_sym8_gather/
8.8 GB
Mac
140
CLEAN — +1 flip/41 (= fp16 ceiling) ✅
Honest bottom line. The sym8 (symmetric-linear int8) Mac bundle is both 3.6× faster AND
clean — at the fp16 ceiling, matching the shipped int8-linear quality. The kernel itself is
bit-exact; quality is purely the expert quantization scheme. An int4 bundle (4.7 GB) was validated
to run on the iPhone 17 Pro (~32 tok/s, the first MoE on the phone) — but the iPhone needs int4
for size and non-QAT int4 is a hard quality wall (two independent 4-bit schemes both land at ~12
introduced flips/41 with large margins; clean int4 would need QAT weights LiquidAI doesn't ship).
So only the clean Mac bundle is shipped; rebuild the int4 variant locally if you want the
on-device version. On a bare prompt the base model itself greedy-degenerates into repetition
(present in fp16 too) — use the chat template + sampling.
The decode graph's input_ids is static [1,1]; prefill runs as S=1 pipelined steps. Convert your
own with conversion/export_lfm2_moe_metal_decode_pipelined.py
(sym8 = clean Mac; int4km = iPhone-compact, not shipped).
License
LFM Open License v1.0 (upstream LiquidAI license, shipped as LICENSE). Conversion/kernel: community.
More models in this format:Core AI Model Zoo — 75 models, each with the recipe that produced it.
Want a different model on-device?Open a request — free, open weights only; the export and its measured numbers get published publicly.