Skip to main content

Needle

A foundation model for mobiles, wearables, robots, smart home, automotive and microcontrollers. The whole model is a single 8-29 MB binary built on our Simple Attention Network, and we trade general chat capacity to beat models 10x its size on mobile tool calls and match 2-3x bigger models on extraction.

  • Tool calls: given the functions your app exposes, Needle picks the right ones and fills every argument from what the user said. Ask for two things and you get two calls in order; ask for something no tool covers and you get an empty list, not a guess.
  • Structured extraction: declare a shape, hand over messy text, get typed fields back: an invoice, a booking, a notification, a form. The decode grammar guarantees the output parses, and extraction generalises to classification.
  • Text embedding: the same model returns a vector for a sentence, so an app can search, match and route locally.

Needle 3 at a glance

Needle 3 is a Laddered Simple Attention Network: a Monarch Hadamard MLP in place of the FFN, GQA attention with causal conv taps, engram n-gram memory read by gather, and multi-lane hyper-connections, trained so that every depth from 2 to 20 layers is a deployable model. Most of its parameters sit in the engram, so the 121M model does the arithmetic of a 50M one. A byte-level grammar compiled from your schemas constrains every token, and every response carries a calibrated confidence score from a learned head. The architecture diagram is on the release page.

Benchmarks

Tool calling is exact-match accuracy on the full test splits, extraction is field micro-F1 on the full test splits.

Needle 3 against baselines on six benchmarks

The interactive frontier plot, the architecture and the fine-tuning results are at cactuscompute.com/needle.

Get started

pip install neuralos

> **neuralOS vs cactus-needle:** the `neuralos` PyPI distribution is this
> project with the engine **bundled** - its platform wheels ship the engine
> shared library and the base weights (~36 MB), so it works fully offline
> after install. The `needle` command is installed as an alias alongside
> `neuralos`. `pip install cactus-needle` keeps the download-at-runtime
> behavior (engine fetched from HuggingFace on first use).

Try it in the browser at cactuscompute.com/needle; the weights and every platform engine are on Hugging Face.

Decorate a function: the signature gives the argument types, the docstring is the tool description, and run() completes the loop, executing your function and returning its results.

import needle

@needle.tool
def get_weather(city: str):
    "Get the current weather for a city."
    return {"city": city, "temp_c": 27, "sky": "clear"}

agent = needle.Needle(tools=[get_weather])
print(agent.run("what's it like in Lagos right now?")["results"])
# [{'city': 'Lagos', 'temp_c': 27, 'sky': 'clear'}]

Every turn returns one JSON object with function_calls, the model's reasoning and a calibrated confidence; an off-topic request returns an empty list rather than a guess. needle.Needle(tools=[...], generation=2) keeps running Needle 2 for existing deployments.

Guides

  • How to design tools for Needle 3: one tool per action, names users would say, formats in descriptions, constraints in the grammar, triggers.
  • Leveraging Needle's confidence: what the score measures, what the engine withholds, and routing on act, confirm or refuse.
  • Structured JSON extraction with Needle: the record as the only tool, typed results, classification with enums.
  • Fine-tuning Needle: the data format, the commands, reading the loss, sizing the dataset.
  • Needle Python docs: the API, the response shape, the behaviour contract, system facts, tool retrieval, offline devices, environments, the CLI.
  • What devices are supported on Needle: every platform folder, the CLI runner, the C API, the browser, WASI, air-gapped setup.
  • The .cact format: the file the engine maps and reads in place, Cactus Quants at 2.125 bits per weight, and how to parse it yourself.
  • Porting Needle 3: notes for writing your own runtime, the oracle to test against, the tensor order the container promises, the prompt on the wire, the ladder rule, retrieval with needle_embed.

llms.txt in this repo carries the same reference for AI coding assistants.

Customisation

Needle was designed to be customised. Its capacity is a ladder, and a subnetwork as small as 2 layers, fine-tuned on one product's tools, runs optimally on devices far smaller than the full model needs. Fine-tuning on DroidCall lifts every subnetwork by 18 to 36 points, and from 4 layers up the tuned subnetwork passes DeepSeek V4 Flash, starting at 29M parameters.

Every subnetwork before and after fine-tuning on DroidCall and on Mobile Actions

Two ways to fine-tune, from the same package:

Local, needle finetune Platform, needle platform finetune
What trains LoRA adapters on the attention projections, base frozen, merged at export The full model, every depth from 2 layers up
What it keeps Your data only Your data reinforced with Needle's original dataset, so nothing already learned is unlearned
Confidence Head untouched; confidence is None Head fine-tuned with the model, calibrated on your tools
Precision 4-bit 2-bit, the same post-training as the shipped model
Data Your JSONL, query/answers or chat format Yours, or generated from your tool definitions, 100 to 10,000 examples per run
Scores Validation loss Validation and test accuracy for every depth
Compute Your machine, JAX on CPU, CUDA or Metal Cactus GPUs
Runs from The CLI The CLI, Python, the dashboard, or a coding agent holding your key

Local:

pip install "cactus-needle[train]"
needle finetune data.jsonl --epochs 10 --out adapter.safetensors
needle build --lora adapter.safetensors --layers 8 --out tuned.cact

Platform, with a key from the console in NEEDLE_API_KEY. One command uploads the files, trains and scores every size, and downloads the .cact files; once a job is submitted it can also be followed on the dashboard:

export NEEDLE_API_KEY=needle_ft_...
needle platform generate --tools tools.json --examples 1000 --out ./data
needle platform finetune data/train.jsonl data/validation.jsonl data/test.jsonl --suffix smart-home --out ./models
from needle.platform import Platform

client = Platform()
job = client.wait(client.finetune(["train.jsonl"], ["validation.jsonl"], ["test.jsonl"], suffix="smart-home"))
paths = client.download(job["fine_tuned_model"], "models", depth=8)

Or hand the key to Claude Code or Codex with cactuscompute.com/llms.txt and let the agent run the loop. needle platform jobs | models | files | billing list what the account holds, needle download model-<id> fetches a model by id, and the fine-tuning guide covers the data format and how to read the scores.

Deploy

Every deployment target ships a prebuilt engine under 1 MB that loads the needle3.cact weights at start. needle build --platform <folder> [--layers N] fetches that engine and puts the weights beside it.

One engine per platform folder

needle build --platform macos-arm64
needle build --platform linux-arm64 --layers 8 --out ./pi
./macos-arm64/needle --model needle3.cact --tools tools.json --serve

The devices guide lists every folder and what ships in it.

By default, telemetry is turned on in the binary. To turn it off, set environment variables NEEDLE_TELEMETRY=0 and DO_NOT_TRACK=1.

Citation

Needle is built by the Cactus Compute team. If you use it in your work, please cite:

@misc{needle3_2026,
  title        = {Needle: Automation Foundation Model for Tiny Devices},
  author       = {Ndubuaku, Henry and Mosoyan, Karen and Mroz, Jakub and Cylich, Noah and
                  Kumar, Satyajit and Sandhu, Parkirat and Shemet, Roman and Lee, Justin H.},
  year         = {2026},
  organization = {Cactus Compute, Inc.},
  howpublished = {\url{https://github.com/cactus-compute/needle}}
}

Metadata

Release files for neuralos 3.0.2

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Built distributions (wheels)

Table of built distributions (wheels) for neuralos 3.0.2
File
neuralos-3.0.2-py3-none-win_amd64.whl Python 3 none Windows x86-64 Details
neuralos-3.0.2-py3-none-manylinux2014_x86_64.whl Python 3 none Linux glibc 2.17+ x86-64 Details
neuralos-3.0.2-py3-none-manylinux2014_aarch64.whl Python 3 none Linux glibc 2.17+ ARM64 Details
neuralos-3.0.2-py3-none-macosx_11_0_arm64.whl Python 3 none macOS 11.0+ ARM64 Details
neuralos-3.0.2-py3-none-any.whl Python 3 none any Details

Total release size: 136.7 MB

Release files / neuralos-3.0.2-py3-none-win_amd64.whl

Download URL neuralos-3.0.2-py3-none-win_amd64.whl
Size 34.2 MB
Tags Python 3 Windows x86-64
SHA-256 checksum
How to use checksums
efb51837ccbfe3955aa872879accf55be37919114dfac631b4435ea4702396dc
BLAKE2b-256 checksum
How to use checksums
848937d5eba8ad076a2e62817fb535b340121c52b59a1dc824c045ea81655280
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/7.0.0 CPython/3.14.7

Release files / neuralos-3.0.2-py3-none-manylinux2014_x86_64.whl

Download URL neuralos-3.0.2-py3-none-manylinux2014_x86_64.whl
Size 34.2 MB
Tags Linux glibc 2.17+ x86-64 Python 3
SHA-256 checksum
How to use checksums
d01afab15a1b25e1f052fda60c33a1faf71c9fe66c81cad9c020a686b3253aaf
BLAKE2b-256 checksum
How to use checksums
68c4bd8c006791b2ae9b600aa3739ead750b96d087936625bfa37bfe36bd817f
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/7.0.0 CPython/3.14.7

Release files / neuralos-3.0.2-py3-none-manylinux2014_aarch64.whl

Download URL neuralos-3.0.2-py3-none-manylinux2014_aarch64.whl
Size 34.2 MB
Tags Linux glibc 2.17+ ARM64 Python 3
SHA-256 checksum
How to use checksums
3c1d4c2c0a4790d8f2f39a6e9dd71ba985a31c395d7009727e07081257eed5b2
BLAKE2b-256 checksum
How to use checksums
5c6f880eb4fcfffe6b1c5ced7eb0e46650d01be67a783cd687c57c283602f643
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/7.0.0 CPython/3.14.7

Release files / neuralos-3.0.2-py3-none-macosx_11_0_arm64.whl

Download URL neuralos-3.0.2-py3-none-macosx_11_0_arm64.whl
Size 34.0 MB
Tags Python 3 macOS 11.0+ ARM64
SHA-256 checksum
How to use checksums
da24aa075e86d9fa1a628b2d475ab76cd48571d5dbf3b53f12b88f2eb48cde20
BLAKE2b-256 checksum
How to use checksums
a8a13354ec67fd627893c7cd6c93cd3455996180201fb1a60e664ef8fe8bf7cf
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/7.0.0 CPython/3.14.7

Release files / neuralos-3.0.2-py3-none-any.whl

Download URL neuralos-3.0.2-py3-none-any.whl
Size 99.5 kB
Tags Python 3
SHA-256 checksum
How to use checksums
94c939c33f808564d2e7b90be4854426bed20eed1c357c1d85785968921a7d54
BLAKE2b-256 checksum
How to use checksums
df8868ac5d14aafcdd950ba834ade84936f64ff61fa9ba8308742422847062bc
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/7.0.0 CPython/3.14.7

Release history Release notifications | RSS feed

3.0.3

5 release files

This release

3.0.2 This release

5 release files

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page