---
license: mit
library_name: mlx
tags:
  - mlx
  - function-calling
  - tool-use
  - encoder-decoder
  - apple-silicon
---

# Needle MLX

An MLX safetensors format conversion of
[Cactus-Compute/needle](https://huggingface.co/Cactus-Compute/needle), a
26M-parameter encoder-decoder function-calling model.

This is not a fine-tune or a quantization. The published checkpoint is loaded
using Needle's declared `bfloat16` inference dtype, then stored as MLX
safetensors so it preserves the upstream runtime's executable values.

## What is included

- `model.safetensors`: 31 converted tensors, 26,315,421 parameters.
- `needle_mlx.py`: a small custom MLX inference implementation for Needle's
  architecture.
- `tokenizer/`: the upstream SentencePiece tokenizer files.
- `config.json` and `manifest.json`: architecture and conversion provenance.

## Use

```python
from needle_mlx import NeedleModel

model = NeedleModel.from_pretrained(".")
logits = model.forward([[1, 2, 3]], [[1, 4]])
```

This is an MLX-native package, not an MLX-LM or oMLX model yet. Needle uses a
custom JAX/Flax architecture, so load it with the included runtime or add a
dedicated adapter to the serving runtime.

## Conversion and verification

The published `needle.pkl` checkpoint was read with a restricted NumPy-only
pickle loader, converted to MLX `bfloat16` safetensors, and checked
tensor-for-tensor after the same dtype cast used by Needle's upstream runtime.

- Source SHA-256:
  `40a32e91d1d4197bf15ba559b74f6727c342dc8746918742fc7d8e2c1f18df40`
- Converted `model.safetensors` SHA-256:
  `7b9d5f0d6ddeb7fbb20f4e45f3f616919357e5d08b5778859fdb762a33d60dae`
- Verification: 31/31 tensors equal the source after Needle's `bfloat16`
  runtime cast; an MLX encoder-decoder smoke pass produced logits with shape
  `(1, 2, 8192)` and generated the upstream weather tool-call example.

The converter source is available at
[seeker-cyber-maker/needle-mlx-depicklinator](https://github.com/seeker-cyber-maker/needle-mlx-depicklinator).

## Credits and license

Needle was created by Cactus Compute. See the
[upstream model card](https://huggingface.co/Cactus-Compute/needle) and
[source repository](https://github.com/cactus-compute/needle) for the model,
training details, and citation. The upstream model card publishes Needle under
the MIT license; this converted package retains that license.