janhq/Jan-v1-4B

[](https://github.com/menloresearch/deep-research) [](https://opensource.org/licenses/Apache-2.0) [](https://jan.ai/) **Jan-v1** is the first release in the **Jan Family**, designed for agentic reasoning and problem-solving within the [Jan App](https://jan.ai/). Based on our [**Lucy**](https://huggingface.co/Menlo/Lucy) model, Jan-v1 achieves improved performance through model scaling. Jan-v1 uses the [Qwen3-4B-thinking](https://huggingface.co/Qwen/Qwen3-4B-Thinking-2507) model to provide enhanced reasoning capabilities and tool utilization. This architecture delivers better performance on complex agentic tasks. For question-answering, Jan-v1 shows a significant performance gain from model scaling, achieving 91.1% accuracy. *The 91.1% SimpleQA accuracy represents a significant milestone in factual question answering for models of this scale, demonstrating the effectiveness of our scaling and fine-tuning approach.* These benchmarks evaluate the model's conversational and instructional capabilities. Jan-v1 is optimized for direct integration with the [Jan App](https://jan.ai/). Simply select the model from the Jan App interface for immediate access to its full capabilities. **Using vLLM:** vllm serve janhq/Jan-v1-4B \ --host 0.0.0.0 \ --port 1234 \ --enable-auto-tool-choice \ --tool-call-parser hermes **Using llama.cpp:** llama-server --model Jan-v1-4B-Q4_K_M.gguf \ --host 0.0.0.0 \ --port 1234 \ --jinja \ --no-context-shift temperature: 0.6 top_p: 0.95 top_k: 20 min_p: 0.0 max_tokens: 2048 - **Discussions**: [HuggingFace Community](https://huggingface.co/janhq/Jan-v1-4B/discussions) - **Jan App**: Learn more about the Jan App at [jan.ai](https://jan.ai/) By default we have system prompt in chat template, this is to make sure the model having the same performance with the benchmark result. You can also use the vanilla chat template without system prompt in the file [chat_template_raw.jinja](https://huggingface.co/janhq/Jan-v1-4B/blob/main/chat_template_raw.jinja). Updated Soon