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Show HN: Cactus Needle 3: 8-29MB automation models can match DeepSeek V4 Flash

87 pointsby 18h agocactuscompute.com
39 comments
Hey HN, Henry from Cactus here.

We submitted Needle 2 here a few weeks ago, and the feedback in the discussion thread was incredibly valuable, thanks! Thanks to all that feedback, we’ve been able to move quickly to release Needle 3 and I'd love to hear what you think again.

The key features:

1) Automation (tool calls & structured JSON output): Needle still doesn't chat by design, its quite challenging to pack general capacity into such small models, so we focus on tool calls and structured JSON. If no tool you declared fits the request, you get an empty list back (note for when playing with the demo).

2) Intelligence Laddering: Every layer (2 to 20) is a deployable subnetwork, so one set of weights, 25 to 121 million parameters at 2-bit, shipping as 8-29MB binaries. On a Raspberry Pi 5 it decodes at up to 4k tokens/sec and prefills at up to 10k.

3) Monarch Hadamard MLP: replaces the dense FFN with three learnable Walsh-Hadamard-initialized Kronecker (Monarch) factor pairs interleaved with per-channel diagonal scales, fixed permutations, a SiLU nonlinearity, and a rank-8 input-conditioned gate, so each token gets a fully mixed nonlinear transform of its d_model channels at O(d√d) parameters and compute instead of the O(d²) a dense 4x-expansion MLP would cost.

4) Performance: On Mobile Actions (phone commands, scored on the exact call) the 20-layer model gets 86.0 through the shipped 2-bit binary; LFM2.5 1.2B is at 82.4, Qwen3.5 0.8B at 76.0, Apple's on-device model at 57.6, all at f16. More results on the link, we do not win everywhere ofc.

5) Multilingual: Needle 3 now supports English, French, Spanish, German, Dutch, Italian, Polish, with more languages coming.

6) Finetuning: You can achieve DeepSeek v4 Flash grade performance on a narrow task with just 4L, stress on "narrow task", we found that production users often prefer tuning before production.

7) Triggers: Grounding is a common challenge for tool call, at least for Needle 2, so we added support case-insensitive regular expressions matched against each request to gate false negatives.

8) Confidence: Every response also carries a calibrated confidence score, the minimum of a judgement on the finished call and its decode probability. Act above your threshold, show the call and ask below it, or escalate to a bigger model.

9) Supported Platforms: macOS, Linux on x86-64, ARM64, ARMv7, RISC-V and MIPS32, Windows x64 and ARM, Android, iOS, watchOS, tvOS, the browser as WebAssembly, and a WASI component.

Thanks for reading and as always, thoughts appreciated!

2h agoHN ↗

None of the queries I asked worked:

- "more light"

- "less light"

- "both doors should be locked"

- "if blinds are open, open back door"

2h agoHN ↗

thanks for this actually, so the demo is a preset, you can edit tools descriptions and add available tools the way you want, else Needle heavily guards against false negatives, users asked for this. For this, we will update presets on our end.

2h agoHN ↗

My thought, the growing number of dubious claims that a tiny model beats LLMs will make any useful innovation be overlooked.

What's more important than the resource requirements is to highlight what the model simply cannot even attempt to do that general LLMs do decently well.

In other words, tell me the anti use case clearly so that I don't have to find out myself.

2h agoHN ↗

Strong point! Needle is a task-specific model and bullet 6 stressed that it is only trained to be good on a set of narrow tasks, but I guess it could be clearer?

1h agoHN ↗

It would be clearer if you didn't use AI to reply.

1h agoHN ↗

An LLM is a Swiss Army knife. This is a corkscrew.

All of the other tasks a general-purpose LLM can do (write me a poem about pizza, rewrite this code in rust, tell me about the causes of the war of the roses) are unsupported.

The only use case this supports is converting unstructured text into structured json calls, and doing that quickly in a low memory environment.

2h agoHN ↗

Apart from fictional use cases, what is the real use case here? The pricing on some open models are absurdly low for generic tasks. For the privacy conscious it makes sense to run something like a 8-27B on local network and get the work done.

Are there perhaps some industrial or agri use cases?

2h agoHN ↗

Fair, we gotta do a better job at explaining this properly!

So an 8-27B on a LAN box wins for generic tasks on hardware that can hold it. Needle is for hardware that can't, like plain ARMv7, MIPS32 (the Ingenic chips in cheap IP cameras), RISC-V and watches. Also, we found cost to not really be the lever for on-device models, but availability and latency.

1h agoHN ↗

A list of hardware platforms doesn't make a use case. Do you have an active deployment of Needle that is noticeably useful, and if so, what do you have it do?

2h agoHN ↗

Wondered if it'd turn on the lights in the bathroom with these:

"I need a wee" -> tries to play music because "wee" is a genre

"I need a wee wee" -> starts the vaccuum in the bathroom

"I'm going to the toilet" -> says it'll turn on the toilet, and I'm not totally sure what that entails.

"I'm going to the toilet and can't see" -> reasons that lights should be on in the bathroom, then chooses again to turn on the toilet.

"I'm going to the toilet and can't see where I'm going" -> reasoning is "'going to the toilet' -> control_device with device 'coffee maker' (toilet implies coffee maker)"

"I'm going to the toilet and can't see where I'm going because it is too dark" -> "'dark' -> direction 'dark'; adjust_lights with brightness 100 for darker light"" and chooses to turn the lights in the living room to "dark" which fails.

At this point the vacuum is in a dark bathroom, the living room is 100% brightness and playing "wee". At least there's coffee.

2h agoHN ↗

thanks for these haha, you can actually edit the tools and/or their descriptions, the demo is just a "get started" preset. But still we do have room for reasoning improvement!

2h agoHN ↗

I have an idea for a use case for this, and I'm wondering if you think it makes sense or if you have any thoughts on the approach.

I'm a big fan of OpenStreetMap, and I enjoy editing it from my computer. From my phone, I find it quite tedious trying to make sure I type in the phone number exactly correctly and double-check it, or find and select the right field from the large list of fields available in Upredor.

Generally, how it works is I see a restaurant, and there's a sign. I know that it says, "Cash only. Here's the phone number. Here's the opening hours." What would be really cool is if I could just speak to the phone and say, "Hey, here's the information about this place." It would automatically use your location to detect what places are nearby and maybe even detect which place you're talking about, and then tell you, "Okay, here are the changes I think you're proposing to make, or these things you stated are the ones that would create a diff." This would be limited to just perhaps the 20 most common keys in some predefined set of values for most of them. Like cuisine=x should just match to the most common not make up new ones.

Of course, this is something a large language model could do, but having it run on device would be a lot nicer and cheaper.

1h agoHN ↗

Makes a lot of sense! declare one record with the ~20 keys as fields, cuisine and friends as enums with the common values, and the grammar can't produce a value outside the set; fields with no evidence come back empty, so the output is exactly the diff.

For "which place", query nearby POIs from location in the app and pass the candidate names as an enum field, so Needle picks rather than guesses.

Two caveats: it's text-in, so you need on-device STT first, and opening_hours syntax is the risky bit, so either put the format in the description or capture the raw hours and normalise in code.

2h agoHN ↗

Why are you out here swinging against DeepSeek V4 Flash? Jev is your opponent here.

1h agoHN ↗

True! We finished Needle 3 before Jev launched. Also, we are merely chasing one DeepSeek v4 Flash capacity with a small model, DeepSeek models are really good.

1h agoHN ↗

"turn all the lights on/off" and "it's too dark in the bathroom" worked for me, but anything less direct didn't. "it's too cold" actually made it turn the thermostat down ("it's cold" made it... turn the lights down?)! Although the confidence on the bad responses was pretty low, so it might be worth adding a threshold to the demo.

Or maybe it just has a weird thermostat down bias? "make it hot" also had it turn it down (specifically it went from 20->18, or at least tried to, the UI still showed 20), with high confidence. Also might have a bit of a Celsius vs Fahrenheit confusion. Neat concept, but I might not want to let it control the oven at the moment.

The laptop demo worked better until I tried to open the mail app. "Check mail" kept opening the browser with an error, and "check email" makes a note with the text "email", "open email" goes to "https://api.email.com/v1/email" in my real browser, but "open mail" does work.

And I presume the "reasoning" isn't very trustworthy? In the car I got "'turn it up' means lower volume -> set_volume with lower value." For the house, reasoning would correctly say that I wanted the alarm off, but it didn't actually do it.

58m agoHN ↗

Hey, thanks a lot for this feedback, very useful and actionable for us! Quite a few of these came down to our tool definitions in the playground as well as out triggers. We updated them just now and these should be more reliable. Really this goes to show that needle shines through after putting in the work to make the tool list around it good for your use case. As for the reasoning, yes its main function is really to provide more words/keywords that the model can latch onto when generating the tool call response, since this is a SAN model it needs more grounding in existing context.

1h agoHN ↗

Hey, I’m really happy that someone is building this. I tried doing something similar a couple of months ago and came to the conclusion that the dataset was at least as important as the modeling itself. Building a good dataset is nowhere near as flashy as building a novel model architecture, but it really is critical.

For instance, you want to be able to handle any smart home commands people could issue, right? What are all of the smart home devices? What are all of the ways people might want to issue commands? Also, for things like Spotify, it’s not going to know what “The Beatles” are or “Led Zeppelin”. Artist and song names themselves are easily just as hard as all of the smart home devices combined.

The simple attention network stuff is cool, it makes sense to drop the MLP when it dominates the param count. But you’ll definitely lose some “world knowledge”. That’s probably ok though.

1h agoHN ↗

100%, data was honestly most of the work, Needle 3 is trained on 360B tokens of structured data and we spend way more time on the generation pipeline than on the model. On Led Zeppelin, Needle doesn't actually need to know it, arguments are copied from the request so it just lifts the name into the artist field. The knowledge went into the engram btw, 70M of the 121M params are n-gram tables, so it can tell artist vs song without an MLP. Also yes, "play their second album" won't work, that needs the world knowledge it doesn't have.

1h agoHN ↗

8-29MB models for structured JSON output are compact yet functional.

1h agoHN ↗

Yes, it was really difficult to compress meaningfully intelligence down to that, and there are many limitations we are aware off and still improving on.

1h agoHN ↗

from my limited tests, it can work with up to 10 tools/definitions.

over that and it gets confused

1h agoHN ↗

Hi, thanks for the feedback! And yes absolutely less tools and better tool descriptions make a huge difference for this model.

1h agoHN ↗

I told the "car" to close the garage door and turn the car on and it didn't immediately refuse

51m agoHN ↗

haha i think that's a good demonstration of how external guardrails could help ground tiny models like these to prevent issues from coming up. I wouldn't trust needle to be my autopilot either (:

4m agoHN ↗

I don't think you're taking this seriously enough if you think external guardrails are sufficient.

55m agoHN ↗

"Turn the kitchen to 230°C" was executed with "confidence": 0.9015

48m agoHN ↗

lol well i guess you can turn the whole kitchen into an oven with needle :)

But for real usecases you are able to set explicit minimum and maximum values on the output range of numeric arguments, so that you can avoid situations like these. In this case it was hard for us to do that while keeping a broadly appealing demo since celsius and fahrenheit have different "reasonable" output ranges.

41m agoHN ↗

I tried the phone model:

"My car crashed I need help"

{ "'crashed' implies need for music. 'play_music' with query 'car crashed' from user's words.", ..., "confidence": 1, }

14m agoHN ↗

Hey, thanks for the feedback! I think this is a useful part of a demonstration so I added a 911 tool specifically to demonstrate this capability and the fact that you can guard it with triggers that make it so calling emergency is an unambiguous action given the input. This really shows that constructing the right tool set with the right surrounding setup is a priority when deploying needle.

33m agoHN ↗

This could be really handy for triggering admin functionality. Would be kind of nice to just quickly be able to say "Reboot <server>" to a chat instead of digging through a GUI (especially when you're remote/in the field).

23m agoHN ↗

Oh yeah really good use case! Definitely something to finetune the model for so that it gains better task-specific reliability, because rebooting the wrong server could easily be catastrophic.

32m agoHN ↗

I tried this today for labelling - and for that task it was very bad MNLI was better - so you are going to need to match the use case for this pretty exactly. (at 29MB params one would expect that!) I'm obviously not saying labelling is a good use case :-) just adding a data point.

Jev has put the cat amongst the pigeons so suddenly everyone is looking at classifiers and encoder only models again.

My ideal model would be a general purpose LLM API that can answer classification questions and as it does so distils to an encoder only model so that the more classifications I do the cheaper it gets (i.e. the more it offloads to the classifier). If anyone ever wants to do this as a service do let me know, because it's just another piece of code to manage in each new project that needs classification.

Also a model that could do this internally would be nice :-)

20m agoHN ↗

Hey! Yeah I think for labelling the model would need to have much better world knowledge than its current size allows. Jev really is a very good model, I think it has a very strong place in the upcoming tech stacks. Really good suggestion to make a continuously distilled model, we are going to have to look into that one :)

21m agoHN ↗

Also FYI doesn't run inference on Apple GPU (only for training)

18m agoHN ↗

Hey there, yep we found that on Apple devices specifically running on CPU is fast enough that Metal support is not needed. Thanks for flagging this though, and if usecases that would benefit from Metal support come up we will be adding it to the binaries.

13m agoHN ↗

I'll try to get something set up to try this out. I've been working on an ESP32 based Echo replacement that sends audio back to a backend server I run, and one question I had was whether models small enough to run on a Mac Mini or even smaller hardware are good enough to handle basic tool calling functionality with a bit of reasoning where needed.

I have a test suite that tries like ~36 different scenarios, including things like starting multiple timers, saying "actually cancel that timer" and whether it knows to do that one you just created. Basic decision making on top of tool calling. I found so far that, for example, Qwen3.8 on my local machine does pretty poorly even relative to Gemma4 E4B (~9.6gb) and that the best price/performance outcome I've found so far with openrouter is actually GPT Luna, but obviously I'd love to get something that works as well running locally for privacy reasons.

Would love to try this out, I'll just need to tweak my benchmarker to use however this serves it.

9m agoHN ↗

Hey there! If you end up trying out needle on the test suite it would be very useful for us if you could share some failure modes of the model! We are always trying to understand where the model isn't doing good and where we can make it better.

For your question on tool calling, I think you will find that the model is pretty good at simpler tool calls and parallel ones, but can struggle with implied references and multistep reasoning. These are definitely things that can improve with task-specific finetuning but for some things you just have to have a model that is properly sized. That said, we are always trying to improve the model so that it can handle an ever larger set of queries