# hqq-quantization

A skill that walks the agent through Half-Quadratic Quantization of LLM weights to 8/4/3/2/1-bit precision without a calibration dataset. Useful when you need a compressed model fast and want it running in vLLM or Transformers.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 962 installs · ★ 13984
- Author: Orchestra Research
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/Orchestra-Research/AI-Research-SKILLs/tree/HEAD/10-optimization/hqq/SKILL.md
- Updated: 2026-10-11
- HTML: https://affpapa.org/en/nevibecode/skills/hqq-quantization

## What it does

The skill teaches the agent how to set up HQQ: you define a `BaseQuantizeConfig` with bit width, group size and axis, then swap `nn.Linear` for `HQQLinear`. For a full model the same parameters go into `HqqConfig` passed to `AutoModelForCausalLM.from_pretrained`.

Inference backends are covered too: plain PyTorch, `pytorch_compile`, ATEN, TorchAO int4, GemLite, BitBlas and Marlin. Marlin targets Ampere and newer GPUs, while BitBlas and TorchAO need their own packages installed. There is a section on mixed precision, with attention at 4 bits and MLP layers at 2 bits, plus notes on fine-tuning a quantized model with LoRA/PEFT.

You need `hqq>=0.2.0` and `torch>=2.0.0`. Pre-quantized HQQ checkpoints on the HuggingFace Hub can be loaded and used for generation right away. For serving, the skill shows launching a model through vLLM with `quantization="hqq"`.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add Orchestra-Research/AI-Research-SKILLs --skill hqq-quantization -a claude-code
```
```bash
npx skills add Orchestra-Research/AI-Research-SKILLs --skill hqq -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/hqq/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/hqq/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add Orchestra-Research/AI-Research-SKILLs --skill hqq -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/hqq/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add Orchestra-Research/AI-Research-SKILLs --skill hqq -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/hqq/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install Orchestra-Research/AI-Research-SKILLs hqq
```

2. **Manually: put the files in place**
- File: `.github/skills/hqq/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add Orchestra-Research/AI-Research-SKILLs --skill hqq -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/Orchestra-Research/AI-Research-SKILLs --path 10-optimization/hqq
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/hqq/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add Orchestra-Research/AI-Research-SKILLs --skill hqq -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/Orchestra-Research/AI-Research-SKILLs/tree/HEAD/10-optimization/hqq/SKILL.md

## When to use it
- quantize a model to 4 bits with no calibration dataset
- fit an LLM into a single GPU at 2-bit precision
- pick an inference backend that matches your GPU
- mix precision across layers: attention at 4 bits, MLP at 2
- fine-tune a quantized model with LoRA

## Example prompts
- Quantize meta-llama/Llama-3.1-8B to 4 bits with HQQ and save it to ./llama-8b-hqq-4bit
- Set up HQQ with nbits=2 and group_size=16 for MLP layers, keep attention at 4 bits
- Serve the HQQ model through vLLM with quantization="hqq"

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: b91def4e77e7894d.

BEGIN THIRD-PARTY FILE b91def4e77e7894d
````text
---
name: hqq-quantization
description: Half-Quadratic Quantization for LLMs without calibration data. Use when quantizing models to 4/3/2-bit precision without needing calibration datasets, for fast quantization workflows, or when deploying with vLLM or HuggingFace Transformers.
version: 1.0.0
author: Orchestra Research
license: MIT
tags: [Quantization, HQQ, Optimization, Memory Efficiency, Inference, Model Compression]
dependencies: [hqq>=0.2.0, torch>=2.0.0]
---

# HQQ - Half-Quadratic Quantization

Fast, calibration-free weight quantization supporting 8/4/3/2/1-bit precision with multiple optimized backends.

## When to use HQQ

**Use HQQ when:**
- Quantizing models without calibration data (no dataset needed)
- Need fast quantization (minutes vs hours for GPTQ/AWQ)
- Deploying with vLLM or HuggingFace Transformers
- Fine-tuning quantized models with LoRA/PEFT
- Experimenting with extreme quantization (2-bit, 1-bit)

**Key advantages:**
- **No calibration**: Quantize any model instantly without sample data
- **Multiple backends**: PyTorch, ATEN, TorchAO, Marlin, BitBlas for optimized inference
- **Flexible precision**: 8/4/3/2/1-bit with configurable group sizes
- **Framework integration**: Native HuggingFace and vLLM support
- **PEFT compatible**: Fine-tune quantized models with LoRA

**Use alternatives instead:**
- **AWQ**: Need calibration-based accuracy, production serving
- **GPTQ**: Maximum accuracy with calibration data available
- **bitsandbytes**: Simple 8-bit/4-bit without custom backends
- **llama.cpp/GGUF**: CPU inference, Apple Silicon deployment

## Quick start

### Installation

```bash
pip install hqq

# With specific backend
pip install hqq[torch]      # PyTorch backend
pip install hqq[torchao]    # TorchAO int4 backend
pip install hqq[bitblas]    # BitBlas backend
pip install hqq[marlin]     # Marlin backend
```

### Basic quantization

```python
from hqq.core.quantize import BaseQuantizeConfig, HQQLinear
import torch.nn as nn

# Configure quantization
config = BaseQuantizeConfig(
    nbits=4,           # 4-bit quantization
    group_size=64,     # Group size for quantization
    axis=1             # Quantize along output dimension
)

# Quantize a linear layer
linear = nn.Linear(4096, 4096)
hqq_linear = HQQLinear(linear, config)

# Use normally
output = hqq_linear(input_tensor)
```

### Quantize full model with HuggingFace

```python
from transformers import AutoModelForCausalLM, HqqConfig

# Configure HQQ
quantization_config = HqqConfig(
    nbits=4,
    group_size=64,
    axis=1
)

# Load and quantize
model = AutoModelForCausalLM.from_pretrained(
    "meta-llama/Llama-3.1-8B",
````
END THIRD-PARTY FILE b91def4e77e7894d

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