transformers/docs/source/en/model_doc/lfm2.md

This model was released on 2025-07-10 and added to Hugging Face Transformers on 2025-07-10.

LFM2

Overview

LFM2 represents a new generation of Liquid Foundation Models developed by Liquid AI, specifically designed for edge AI and on-device deployment.

The models are available in three sizes (350M, 700M, and 1.2B parameters) and are engineered to run efficiently on CPU, GPU, and NPU hardware, making them particularly well-suited for applications requiring low latency, offline operation, and privacy.

Architecture

The architecture consists of 16 blocks total: 10 double-gated short-range convolution blocks and 6 blocks of grouped query attention. This design stems from the concept of dynamical systems, where linear operations are modulated by input-dependent gates, allowing for "liquid" dynamics that can adapt in real-time. The short convolutions are particularly optimized for embedded SoC CPUs, making them ideal for devices that require fast, local inference without relying on cloud connectivity.

The key architectural innovation of LFM2 lies in its systematic approach to balancing quality, latency, and memory efficiency through our STAR neural architecture search engine. Using STAR, Liquid AI optimized the models for real-world performance on embedded hardware, measuring actual peak memory usage and inference speed on Qualcomm Snapdragon processors. This results in models that achieve 2x faster decode and prefill performance compared to similar-sized models, while maintaining superior benchmark performance across knowledge, mathematics, instruction following, and multilingual tasks.

Example

The following example shows how to generate an answer using the AutoModelForCausalLM class.

from transformers import AutoModelForCausalLM, AutoTokenizer

# Load model and tokenizer
model_id = "LiquidAI/LFM2-1.2B"
model = AutoModelForCausalLM.from_pretrained(
    model_id,
    device_map="auto",
    dtype="bfloat16",
)
tokenizer = AutoTokenizer.from_pretrained(model_id)

# Generate answer
prompt = "What is C. elegans?"
input_ids = tokenizer.apply_chat_template(
    [{"role": "user", "content": prompt}],
    add_generation_prompt=True,
    return_tensors="pt",
    tokenize=True,
)

output = model.generate(
    input_ids,
    do_sample=True,
    temperature=0.3,
    min_p=0.15,
    repetition_penalty=1.05,
    max_new_tokens=512,
)

print(tokenizer.decode(output[0], skip_special_tokens=False))

Lfm2Config

autodoc Lfm2Config

Lfm2Model

autodoc Lfm2Model - forward

Lfm2ForCausalLM

autodoc Lfm2ForCausalLM - forward