Posted by HenryNdubuaku 18 hours ago
We were always frustrated by the little effort made towards building agentic models that run on budget phones, so we conducted investigations that led to an observation: agentic experiences are built upon tool calling, and massive models are overkill for it. Tool calling is fundamentally retrieval-and-assembly (match query to tool name, extract argument values, emit JSON), not reasoning. Cross-attention is the right primitive for this, and FFN parameters are wasted at this scale.
Simple Attention Networks: the entire model is just attention and gating, no MLPs anywhere. Needle is an experimental run for single-shot function calling for consumer devices (phones, watches, glasses...).
Training: - Pretrained on 200B tokens across 16 TPU v6e (27 hours) - Post-trained on 2B tokens of synthesized function-calling data (45 minutes) - Dataset synthesized via Gemini with 15 tool categories (timers, messaging, navigation, smart home, etc.)
You can test it right now and finetune on your Mac/PC: https://github.com/cactus-compute/needle
The full writeup on the architecture is here: https://github.com/cactus-compute/needle/blob/main/docs/simp...
We found that the "no FFN" finding generalizes beyond function calling to any task where the model has access to external structured knowledge (RAG, tool use, retrieval-augmented generation). The model doesn't need to memorize facts in FFN weights if the facts are provided in the input. Experimental results to published.
While it beats FunctionGemma-270M, Qwen-0.6B, Granite-350M, LFM2.5-350M on single-shot function calling, those models have more scope/capacity and excel in conversational settings. We encourage you to test on your own tools via the playground and finetune accordingly.
This is part of our broader work on Cactus (https://github.com/cactus-compute/cactus), an inference engine built from scratch for mobile, wearables and custom hardware. We wrote about Cactus here previously: https://news.ycombinator.com/item?id=44524544
Everything is MIT licensed. Weights: https://huggingface.co/Cactus-Compute/needle GitHub: https://github.com/cactus-compute/needle
[0]: http://www.incompleteideas.net/IncIdeas/BitterLesson.html
But how do you get 'Paris' into the value vector in that case? The value vector is just the result of a matrix multiplication, and without a nonlinearity it can't perform a data-dependent transformation. Attention still acts as a nonlinear mixer of previous values, but your new output is still limited to the convex combination of previous values.
Ok wait I think I see what you mean. Although maybe it's not getting paris _into_ the value vector that's hard, but isolating the residual stream to _only_ that instead of things like other capitals.
So as a naive example maybe at the very first layer consuming your tokens: Q{France} would have high inner product with K{capital} and so our residual would now mostly contain V{capital}, which maybe contains embeddings of all the capitals of all countries. You need some way to filter out all the other stuff, but can't do that without a FFN + activation.
Just throwing in a relu by itself won't help since that would still work on all the elements uniformly, you need some way to put weight on "paris" while suppressing the others, i.e. mixing within the residual stream itself.
Although maybe if you really stretch it, somewhere in a deeper layer you could have 1-hot encoded values with a "gain" coefficient so that when you do the residual addition it's something like {<paris>, <tokyo>, <dc>} + 10000*{<1>, <0>, <0>} and then if you softmax that you get something with most of its mass on "Paris". But it seems like this would not be practical, or it's just shifting the issue to how that the right 1-hot vector is chosen
Result: [{"name":"set_timer","arguments":{"time_human":"1 hour"}}]
Query: in 1 hour set a timer for 1 hour
Result: [{"name":"set_timer","arguments":{"time_human":"1 hour"}}]
I'd expect either a chain load or just a 2 hour timer. Further attempts humorously give two separate 1-hour-timers.