Pulpie Orange Small MLX

This repository contains MLX weights for feyninc/pulpie-orange-small, a 210M-parameter EuroBERT token-classification model for main-content extraction from HTML.

The source checkpoint is an encoder-only EuroBERT model with RoPE, RMSNorm, SwiGLU MLP layers, and a token-classification head. It is not a decoder-only LLM, so this conversion does not use mlx-lm's standard LLM model classes. Instead, this repository includes modeling_eurobert_mlx.py, a small MLX implementation of the source architecture with matching parameter names.

Files

File	Purpose
`model-bf16.safetensors`	Native 16-bit BF16 MLX weights converted from the source checkpoint.
`model-8bit.safetensors`	MLX affine 8-bit weight-quantized variant.
`model-4bit.safetensors`	MLX affine 4-bit weight-quantized variant.
`modeling_eurobert_mlx.py`	MLX EuroBERT token-classification loader.
`mlx_config.json`	Variant metadata and quantization settings.
`verification_report.json`	Load, numerical, extraction, latency, and compute-cost results.
`scripts/convert_to_mlx.py`	Reproducible conversion script.
`scripts/verify_mlx.py`	Reproducible verification script.

Usage

Install dependencies:

pip install -r requirements.txt

Run a forward pass:

import sys
import mlx.core as mx
from huggingface_hub import snapshot_download
from transformers import AutoTokenizer

repo_dir = snapshot_download("Mike0021/pulpie-orange-small-mlx")
sys.path.insert(0, repo_dir)

from modeling_eurobert_mlx import load_model

tokenizer = AutoTokenizer.from_pretrained(repo_dir, trust_remote_code=True)
model = load_model(repo_dir, variant="bf16")  # "bf16", "8bit", or "4bit"

inputs = tokenizer(
    ["<h1>Apple MLX conversion</h1><p>Main article text.</p>"],
    return_tensors="np",
    padding=True,
)
input_ids = mx.array(inputs["input_ids"])
attention_mask = mx.array(inputs["attention_mask"])

logits = model(input_ids, attention_mask)
mx.eval(logits)
print(logits.shape)  # batch, tokens, 2

Minimal Pulpie-style extraction:

import numpy as np
import mlx.core as mx
from pulpie.chunker import extract_blocks, pack_chunks, tokenize_blocks
from pulpie.model_utils import extract_item_ids, predictions_to_labels
from pulpie.reconstruct import extract_main_html
from pulpie.simplify import simplify

html = (
    "<html><body><article><h1>Apple MLX conversion</h1>"
    "<p>This article explains how to convert a EuroBERT content extraction "
    "model to MLX format.</p></article></body></html>"
)

simplified, map_html = simplify(html)
blocks = extract_blocks(simplified)
item_ids = extract_item_ids(blocks)
sep_id = tokenizer.convert_tokens_to_ids("<|sep|>")
chunks = pack_chunks(
    tokenize_blocks(blocks, tokenizer),
    max_tokens=8192,
    sep_token_id=sep_id,
    bos_token_id=tokenizer.bos_token_id,
    eos_token_id=tokenizer.eos_token_id,
)

predictions = [0] * len(blocks)
for chunk_ids, block_indices in chunks:
    ids = mx.array([chunk_ids])
    mask = mx.ones_like(ids)
    logits = model(ids, mask)
    mx.eval(logits)
    logits_np = np.array(logits.astype(mx.float32))[0]
    sep_positions = np.where(np.array(chunk_ids) == sep_id)[0]
    preds = logits_np[sep_positions].argmax(axis=-1).tolist()
    for i, block_idx in enumerate(block_indices):
        predictions[block_idx] = int(preds[i])

labels = predictions_to_labels(item_ids, predictions)
print(extract_main_html(map_html, labels))

Conversion Methodology

Downloaded feyninc/pulpie-orange-small from the Hugging Face Hub.
Inspected config.json, configuration_eurobert.py, and modeling_eurobert.py.
Confirmed the model is EuroBertForTokenClassification with 12 layers, hidden size 768, 12 attention heads, head dim 64, max length 8192, BF16 source weights, and 2 output labels.
Confirmed current MLX can be installed on Linux with mlx[cpu], so no cloud Mac was required for conversion or load verification.
Implemented a custom MLX EuroBERT token-classification module with matching state-dict keys and the source architecture behavior.
Saved the BF16 MLX weights with mlx.core.save_safetensors.
Created 8-bit and 4-bit variants with mlx.nn.quantize, using affine weight quantization, group size 64, over MLX Linear and Embedding modules.
Verified each variant with scripts/verify_mlx.py.

Verification Results

Verification was run on Linux x86_64 using mlx[cpu]. The PyTorch reference was the original source checkpoint loaded in float32 with eager attention. The BF16 variant is expected to have small dtype-level differences versus that float32 reference; quantized variants have larger differences.

Load Checks

Variant	Load result	Test logits shape	Test logits dtype
BF16	Pass	`[1, 3, 2]`	`mlx.core.bfloat16`
8-bit	Pass	`[1, 3, 2]`	`mlx.core.bfloat16`
4-bit	Pass	`[1, 3, 2]`	`mlx.core.bfloat16`

Numerical Accuracy

Test inputs: ["A", "B", "C"], token shape [3, 2].

Variant	Max abs diff vs PyTorch fp32	Mean abs diff	MLX CPU latency
BF16	0.0452327728	0.0191817340	716.88 ms
8-bit	1.2797489166	0.5423613191	9380.58 ms
4-bit	2.2551989555	1.1897996664	9323.18 ms

PyTorch fp32 eager latency on the same input was 50.09 ms on this Linux CPU. The quantized MLX CPU path is slow on this host and should not be read as an Apple Silicon benchmark.

End-to-End Extraction

Sample HTML:

<html><body><article><h1>Apple MLX conversion</h1><p>This article explains how to convert a EuroBERT content extraction model to MLX format.</p></article></body></html>

Pulpie preprocessing produced 2 blocks and one 50-token chunk. All variants loaded, classified both blocks as main, and reconstructed non-empty HTML.

Variant	Predictions	Non-empty output	MLX CPU extraction latency
BF16	`[1, 1]`	Pass	5469.05 ms
8-bit	`[1, 1]`	Pass	78333.61 ms
4-bit	`[1, 1]`	Pass	77852.02 ms

Full machine-readable results are in verification_report.json.

Limitations

This is a custom MLX encoder/token-classification implementation, not an mlx-lm decoder model.
The 8-bit and 4-bit variants are weight-only affine MLX quantizations. They load and pass a small extraction test, but full WebMainBench quality was not re-evaluated.
Linux CPU quantized latency is poor in this environment. MLX is primarily intended for Apple Silicon GPU execution.
The source tokenizer currently emits a Transformers regex warning. The verifier keeps the tokenizer behavior used by the published pulpie package rather than changing token IDs during conversion.

Compute Cost

No paid cloud Mac or hosted GPU was used. Conversion and verification were done locally on Linux x86_64 with the MLX CPU package. Incremental compute cost: $0.00.

License

The source model weights are licensed under CC BY-NC 4.0. This converted checkpoint follows the same non-commercial license. The included conversion and loader code is provided for interoperability with the converted weights.

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MLX

Hardware compatibility

Quantized

Model tree for Mike0021/pulpie-orange-small-mlx

Base model

EuroBERT/EuroBERT-210m

Finetuned

feyninc/pulpie-orange-small

Finetuned

(1)

this model