---
language: en
license: apache-2.0
base_model: Qwen/Qwen3-4B-Instruct-2507
base_model_relation: finetune
tags:
  - text-generation
  - zen
  - zenlm
  - hanzo
  - agent
  - function-calling
  - tool-use
pipeline_tag: text-generation
library_name: transformers
---

# Zen Agent 4b

Compact 4B agent model with strong function calling and tool-use capabilities.

## Overview

Fine-tuned from [Qwen3-4B-Instruct-2507](https://huggingface.co/Qwen/Qwen3-4B-Instruct-2507) (Apache 2.0) with Hanzo identity + agentic-data training + abliteration. Dense Qwen3 architecture, 4B parameters, 256K-token context.

Developed by [Hanzo AI](https://hanzo.ai) and the [Zoo Labs Foundation](https://zoo.ngo).

## Quick Start

```python
from transformers import AutoModelForCausalLM, AutoTokenizer

model_id = "zenlm/zen-agent-4b"
tokenizer = AutoTokenizer.from_pretrained(model_id)
model = AutoModelForCausalLM.from_pretrained(model_id, torch_dtype="auto", device_map="auto")

messages = [{"role": "user", "content": "Hello!"}]
text = tokenizer.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
inputs = tokenizer([text], return_tensors="pt").to(model.device)
outputs = model.generate(**inputs, max_new_tokens=512)
print(tokenizer.decode(outputs[0][inputs.input_ids.shape[1]:], skip_special_tokens=True))
```

## API Access

```bash
curl https://api.hanzo.ai/v1/chat/completions \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "zen-agent-4b", "messages": [{"role": "user", "content": "Hello"}]}'
```

Get your API key at [console.hanzo.ai](https://console.hanzo.ai) — $5 free credit on signup.

## Model Details

| Attribute | Value |
|-----------|-------|
| Base model | [Qwen/Qwen3-4B-Instruct-2507](https://huggingface.co/Qwen/Qwen3-4B-Instruct-2507) |
| Parameters | 4B |
| Architecture | Qwen3 (dense) |
| Context | 256K tokens |
| License | Apache 2.0 |

## Credits

Fine-tuned from [Qwen/Qwen3-4B-Instruct-2507](https://huggingface.co/Qwen/Qwen3-4B-Instruct-2507) by Qwen (Alibaba Cloud), licensed under Apache 2.0. Hanzo adds identity training, agentic-data fine-tuning, and abliteration.

## License

Apache 2.0 — inherited from the [Qwen3-4B-Instruct-2507](https://huggingface.co/Qwen/Qwen3-4B-Instruct-2507) base model.