zen-agent-4b

4B parameter tool-calling agent with Model Context Protocol (MCP) support

Model Details

  • Developed by: Zen Research Authors
  • Organization: Zen Research DAO under Zoo Labs Inc (501(c)(3) Non-Profit)
  • Location: San Francisco, California, USA
  • Model type: language-model
  • Architecture: Qwen3-4B with MCP
  • Parameters: 4B
  • License: Apache 2.0
  • Training: Trained with Zen Gym
  • Inference: Optimized for Zen Engine

🌟 Zen AI Ecosystem

This model is part of the Zen Research hypermodal AI family - the world's most comprehensive open-source AI ecosystem.

Complete Model Family

Language Models:

3D & World Generation:

  • zen-3d - Controllable 3D asset generation
  • zen-voyager - Camera-controlled world exploration
  • zen-world - Large-scale world simulation

Video Generation:

Audio Generation:

Infrastructure:

Usage

Quick Start

from transformers import AutoModelForCausalLM, AutoTokenizer

model = AutoModelForCausalLM.from_pretrained("zenlm/zen-agent-4b")
tokenizer = AutoTokenizer.from_pretrained("zenlm/zen-agent-4b")

inputs = tokenizer("Hello!", return_tensors="pt")\noutputs = model.generate(**inputs)\nprint(tokenizer.decode(outputs[0]))

With Zen Engine

# High-performance inference (44K tokens/sec on M3 Max)
zen-engine serve --model zenlm/zen-agent-4b --port 3690
# OpenAI-compatible API
from openai import OpenAI

client = OpenAI(base_url="http://localhost:3690/v1")
response = client.chat.completions.create(
    model="zenlm/zen-agent-4b",
    messages=[{"role": "user", "content": "Hello!"}]
)

Training

Fine-tune with Zen Gym:

git clone https://github.com/zenlm/zen-gym
cd zen-gym

# LoRA fine-tuning
llamafactory-cli train --config configs/zen_lora.yaml \
    --model_name_or_path zenlm/zen-agent-4b

# GRPO reinforcement learning (40-60% memory reduction)
llamafactory-cli train --config configs/zen_grpo.yaml \
    --model_name_or_path zenlm/zen-agent-4b

Supported methods: LoRA, QLoRA, DoRA, GRPO, GSPO, DPO, PPO, KTO, ORPO, SimPO, Unsloth

Performance

  • Speed: 28K tokens/sec (RTX 4090)
  • Memory: 2.5GB (Q4_K_M) to 8GB (F16)
  • MCP: Full Model Context Protocol support
  • Tools: 100+ function calling accuracy

Ethical Considerations

  • Open Research: Released under Apache 2.0 for maximum accessibility
  • Environmental Impact: Optimized for eco-friendly deployment
  • Transparency: Full training details and model architecture disclosed
  • Safety: Comprehensive testing and evaluation
  • Non-Profit: Developed by Zoo Labs Inc (501(c)(3)) for public benefit

Citation

@misc{zenzenagent4b2025,
  title={zen-agent-4b: 4B parameter tool-calling agent with Model Context Protocol (MCP) support},
  author={Zen Research Authors},
  year={2025},
  publisher={Zoo Labs Inc},
  organization={Zen Research DAO},
  url={https://huggingface.co/zenlm/zen-agent-4b}
}

Links

License

Apache License 2.0

Copyright 2025 Zen Research Authors


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