MLX-VLM

MLX-VLM is a package for inference and fine-tuning of Vision Language Models (VLMs) and Omni Models (VLMs with audio and video support) on your Mac using MLX.

Table of Contents

• Installation
• Usage
  • Command Line Interface (CLI)
  • Chat UI with Gradio
  • Python Script
• Multi-Image Chat Support
  • Supported Models
  • Usage Examples
• Fine-tuning

Installation

The easiest way to get started is to install the mlx-vlm package using pip:

pip install -U mlx-vlm

Usage

Command Line Interface (CLI)

Generate output from a model using the CLI:

# Image generation
mlx_vlm.generate --model mlx-community/Qwen2-VL-2B-Instruct-4bit --max-tokens 100 --temperature 0.0 --image http://images.cocodataset.org/val2017/000000039769.jpg

# Audio generation (New)
mlx_vlm.generate --model mlx-community/gemma-3n-E2B-it-4bit --max-tokens 100 --prompt "Describe what you hear" --audio /path/to/audio.wav

# Multi-modal generation (Image + Audio)
mlx_vlm.generate --model mlx-community/gemma-3n-E2B-it-4bit --max-tokens 100 --prompt "Describe what you see and hear" --image /path/to/image.jpg --audio /path/to/audio.wav

Chat UI with Gradio

Launch a chat interface using Gradio:

mlx_vlm.chat_ui --model mlx-community/Qwen2-VL-2B-Instruct-4bit

Python Script

Here's an example of how to use MLX-VLM in a Python script:

import mlx.core as mx
from mlx_vlm import load, generate
from mlx_vlm.prompt_utils import apply_chat_template
from mlx_vlm.utils import load_config

# Load the model
model_path = "mlx-community/Qwen2-VL-2B-Instruct-4bit"
model, processor = load(model_path)
config = load_config(model_path)

# Prepare input
image = ["http://images.cocodataset.org/val2017/000000039769.jpg"]
# image = [Image.open("...")] can also be used with PIL.Image.Image objects
prompt = "Describe this image."

# Apply chat template
formatted_prompt = apply_chat_template(
    processor, config, prompt, num_images=len(image)
)

# Generate output
output = generate(model, processor, formatted_prompt, image, verbose=False)
print(output)

Audio Example

from mlx_vlm import load, generate
from mlx_vlm.prompt_utils import apply_chat_template
from mlx_vlm.utils import load_config

# Load model with audio support
model_path = "mlx-community/gemma-3n-E2B-it-4bit"
model, processor = load(model_path)
config = model.config

# Prepare audio input
audio = ["/path/to/audio1.wav", "/path/to/audio2.mp3"]
prompt = "Describe what you hear in these audio files."

# Apply chat template with audio
formatted_prompt = apply_chat_template(
    processor, config, prompt, num_audios=len(audio)
)

# Generate output with audio
output = generate(model, processor, formatted_prompt, audio=audio, verbose=False)
print(output)

Multi-Modal Example (Image + Audio)

from mlx_vlm import load, generate
from mlx_vlm.prompt_utils import apply_chat_template
from mlx_vlm.utils import load_config

# Load multi-modal model
model_path = "mlx-community/gemma-3n-E2B-it-4bit"
model, processor = load(model_path)
config = model.config

# Prepare inputs
image = ["/path/to/image.jpg"]
audio = ["/path/to/audio.wav"]
prompt = ""

# Apply chat template
formatted_prompt = apply_chat_template(
    processor, config, prompt,
    num_images=len(image),
    num_audios=len(audio)
)

# Generate output
output = generate(model, processor, formatted_prompt, image, audio=audio, verbose=False)
print(output)

Server (FastAPI)

Start the server:

mlx_vlm.server

The server provides multiple endpoints for different use cases and supports dynamic model loading/unloading with caching (one model at a time).

Available Endpoints

• /generate - Main generation endpoint with support for images, audio, and text
• /chat - Chat-style interaction endpoint
• /responses - OpenAI-compatible endpoint
• /health - Check server status
• /unload - Unload current model from memory

Usage Examples

Basic Image Generation

curl -X POST "http://localhost:8000/generate" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mlx-community/Qwen2.5-VL-32B-Instruct-8bit",
    "image": ["/path/to/repo/examples/images/renewables_california.png"],
    "prompt": "This is today'\''s chart for energy demand in California. Can you provide an analysis of the chart and comment on the implications for renewable energy in California?",
    "system": "You are a helpful assistant.",
    "stream": true,
    "max_tokens": 1000
  }'

Audio Support (New)

curl -X POST "http://localhost:8000/generate" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mlx-community/gemma-3n-E2B-it-4bit",
    "audio": ["/path/to/audio1.wav", "https://example.com/audio2.mp3"],
    "prompt": "Describe what you hear in these audio files",
    "stream": true,
    "max_tokens": 500
  }'

Multi-Modal (Image + Audio)

curl -X POST "http://localhost:8000/generate" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mlx-community/gemma-3n-E2B-it-4bit",
    "image": ["/path/to/image.jpg"],
    "audio": ["/path/to/audio.wav"],
    "prompt": "",
    "max_tokens": 1000
  }'

Chat Endpoint

curl -X POST "http://localhost:8000/chat" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mlx-community/Qwen2-VL-2B-Instruct-4bit",
    "messages": [
      {
        "role": "user",
        "content": "What is in this image?",
        "images": ["/path/to/image.jpg"]
      }
    ],
    "max_tokens": 100
  }'

OpenAI-Compatible Endpoint

curl -X POST "http://localhost:8000/responses" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mlx-community/Qwen2-VL-2B-Instruct-4bit",
    "messages": [
      {
        "role": "user",
        "content": [
          {"type": "input_text", "text": "What is in this image?"},
          {"type": "input_image", "image": "/path/to/image.jpg"}
        ]
      }
    ],
    "max_tokens": 100
  }'

Request Parameters

• model: Model identifier (required)
• prompt: Text prompt for generation
• image: List of image URLs or local paths (optional)
• audio: List of audio URLs or local paths (optional, new)
• system: System prompt (optional)
• messages: Chat messages for chat/OpenAI endpoints
• max_tokens: Maximum tokens to generate
• temperature: Sampling temperature
• top_p: Top-p sampling parameter
• stream: Enable streaming responses

Multi-Image Chat Support

MLX-VLM supports analyzing multiple images simultaneously with select models. This feature enables more complex visual reasoning tasks and comprehensive analysis across multiple images in a single conversation.

Usage Examples

Python Script

from mlx_vlm import load, generate
from mlx_vlm.prompt_utils import apply_chat_template
from mlx_vlm.utils import load_config

model_path = "mlx-community/Qwen2-VL-2B-Instruct-4bit"
model, processor = load(model_path)
config = model.config

images = ["path/to/image1.jpg", "path/to/image2.jpg"]
prompt = "Compare these two images."

formatted_prompt = apply_chat_template(
    processor, config, prompt, num_images=len(images)
)

output = generate(model, processor, formatted_prompt, images, verbose=False)
print(output)

Command Line

mlx_vlm.generate --model mlx-community/Qwen2-VL-2B-Instruct-4bit --max-tokens 100 --prompt "Compare these images" --image path/to/image1.jpg path/to/image2.jpg

Video Understanding

MLX-VLM also supports video analysis such as captioning, summarization, and more, with select models.

Supported Models

The following models support video chat:

1. Qwen2-VL
2. Qwen2.5-VL
3. Idefics3
4. LLaVA

With more coming soon.

Usage Examples

Command Line

mlx_vlm.video_generate --model mlx-community/Qwen2-VL-2B-Instruct-4bit --max-tokens 100 --prompt "Describe this video" --video path/to/video.mp4 --max-pixels 224 224 --fps 1.0

These examples demonstrate how to use multiple images with MLX-VLM for more complex visual reasoning tasks.

Fine-tuning

MLX-VLM supports fine-tuning models with LoRA and QLoRA.

LoRA & QLoRA

To learn more about LoRA, please refer to the LoRA.md file.