MLX

Name: Strands Agents SDK
Author: Strands Agents

strands-mlx is an MLX model provider for Strands Agents SDK that enables running AI agents locally on Apple Silicon. It supports inference, fine-tuning with LoRA, and vision models.

Features:

Apple Silicon Native: Optimized for M1/M2/M3/M4 chips using Apple’s MLX framework
LoRA Fine-tuning: Train custom adapters from agent conversations
Vision Support: Process images, audio, and video with multimodal models
Local Inference: Run agents completely offline without API calls
Training Pipeline: Collect data → Split → Train → Deploy workflow

Installation

Install strands-mlx along with the Strands Agents SDK:

pip install strands-mlx strands-agents-tools

Requirements

macOS with Apple Silicon (M1/M2/M3/M4)
Python ≤3.13

Usage

Basic Agent

import ast
import operator

from strands import Agent, tool
from strands_mlx import MLXModel

@tool
def calculator(expression: str) -> str:
    """Evaluate an arithmetic expression such as "144 ** 0.5" or "450 / 120".

    Args:
        expression: The arithmetic expression to evaluate.
    """
    ops = {ast.Add: operator.add, ast.Sub: operator.sub, ast.Mult: operator.mul,
           ast.Div: operator.truediv, ast.USub: operator.neg}

    def ev(n):
        if isinstance(n, ast.Constant) and isinstance(n.value, (int, float)):
            return n.value
        if isinstance(n, ast.BinOp) and isinstance(n.op, ast.Pow):
            base, exp = ev(n.left), ev(n.right)
            if abs(exp) > 64:
                raise ValueError(f"exponent too large in {expression!r}: {exp}")
            return base**exp
        if isinstance(n, ast.BinOp) and type(n.op) in ops:
            return ops[type(n.op)](ev(n.left), ev(n.right))
        if isinstance(n, ast.UnaryOp) and type(n.op) in ops:
            return ops[type(n.op)](ev(n.operand))
        raise ValueError(
            f"{expression!r} is not arithmetic; supported: + - * / ** and parentheses over numbers"
        )

    return str(ev(ast.parse(expression, mode="eval").body))

model = MLXModel(model_id="mlx-community/Qwen3-1.7B-4bit")
agent = Agent(model=model, tools=[calculator])

agent("What is 29 * 42?")

Vision Model

from strands import Agent
from strands_mlx import MLXVisionModel

model = MLXVisionModel(model_id="mlx-community/Qwen2-VL-2B-Instruct-4bit")
agent = Agent(model=model)

agent("Describe: <image>photo.jpg</image>")

Fine-tuning with LoRA

Collect training data from agent conversations and fine-tune:

from strands import Agent
from strands_mlx import MLXModel, MLXSessionManager, dataset_splitter, mlx_trainer

# Collect training data
agent = Agent(
    model=MLXModel(model_id="mlx-community/Qwen3-1.7B-4bit"),
    session_manager=MLXSessionManager(session_id="training", storage_dir="./dataset"),
    tools=[dataset_splitter, mlx_trainer],
)

# Have conversations (auto-saved)
agent("Teach me about quantum computing")

# Split and train
agent.tool.dataset_splitter(input_path="./dataset/training.jsonl")
agent.tool.mlx_trainer(
    action="train",
    config={
        "model": "mlx-community/Qwen3-1.7B-4bit",
        "data": "./dataset/training",
        "adapter_path": "./adapter",
        "iters": 200,
    }
)

# Use trained model
trained = MLXModel("mlx-community/Qwen3-1.7B-4bit", adapter_path="./adapter")
expert_agent = Agent(model=trained)

Configuration

Model Configuration

The MLXModel accepts the following parameters:

Parameter	Description	Example	Required
`model_id`	HuggingFace model ID	`"mlx-community/Qwen3-1.7B-4bit"`	Yes
`adapter_path`	Path to LoRA adapter	`"./adapter"`	No

Recommended Models

Text:

mlx-community/Qwen3-1.7B-4bit (recommended for agents)
mlx-community/Qwen3-4B-4bit
mlx-community/Llama-3.2-1B-4bit

Vision:

mlx-community/Qwen2-VL-2B-Instruct-4bit (recommended)
mlx-community/llava-v1.6-mistral-7b-4bit

Browse more models at mlx-community on HuggingFace.

Troubleshooting

Out of memory

Use smaller quantized models or reduce batch size:

config = {
    "grad_checkpoint": True,
    "batch_size": 1,
    "max_seq_length": 1024
}

Model not found

Ensure you’re using a valid mlx-community model ID. Models are automatically downloaded from HuggingFace on first use.

MLX