Qwev

Qwev is the tool router inside NuJan, an AI agent app for Android.

What it does

Qwev decides which tool families a request needs, so a small on-device chat model is offered a short tool list instead of all of them. The base model is Qwen/Qwen3.5-0.8B-Base, fine-tuned with LoRA (rank 32), merged, and quantised to GGUF Q4_K_M, about 529 MB. It runs on llama.cpp.

Given a request in a fixed prompt, Qwev outputs a probability for each of 17 route letters at one position. Those routes are 15 tool families, "core tools only", and "just answer". It does not generate text in normal use. qwev.router.json holds the prompt prefix and suffix, the route names, and the token id of each route letter, so a client can read the 17 probabilities directly.

Files

File	Contents
qwev-v1-Q4_K_M.gguf	GGUF Q4_K_M weights, about 529 MB
qwev.router.json	Prompt prefix and suffix, route names, and the token id of each route letter

How NuJan uses it

NuJan offers at most 2 families per request: the most likely ones until they cover 90% of the probability, none below 0.15, within the space left in the context window.

Results

With Qwev, a 2B on-device model completed 10 of 12 test tasks on two phones, against 7 to 8 of 12 without it. A routing decision takes about 0.2 to 0.3 seconds on a recent flagship phone and about 1 second on a 2019 mid-range phone once warm.

Limits

Qwev is for English requests. The 17 routes are NuJan's own tool families, so other apps would need their own mapping. It picks families, not individual tools. Tasks that need a sub-agent are a common miss.

License

Apache-2.0, the same license as the base model.