Jan
repository·main·Indexed 12 days ago
https://github.com/janhq/janAn open-source, local-first ChatGPT replacement that allows users to run LLMs privately on their own hardware or connect to cloud-based AI providers. It includes an OpenAI-compatible API server, a core library (@janhq/core) for building extensions, and an AutoQA E2E test runner for application automation.
What's inside Jan
- Jan is an open-source, privacy-first alternative to Claude and ChatGPT. It allows you to run foundation models entirely on your own hardware, ensuring data privacy and full ownership of your AI stack. Jan supports various deployment modes including desktop applications, web interfaces, and local API servers.
Overview of Jan-v2-VL Vision-Language Model
mainJan-v2-VL is an 8B vision-language model built on Qwen3-VL-8B-Thinking. It is specifically designed for long-horizon, multi-step agentic tasks in software environments like web browsers and desktop applications. It combines language reasoning with visual perception to perform UI control, screenshot grounding, and tool calling (e.g., via BrowserMCP).
Model Variants
Variant Focus Jan-v2-VL-low Efficiency-oriented, lower latency Jan-v2-VL-med Balanced latency and quality Jan-v2-VL-high Deeper reasoning, higher think time Key Capabilities
- Agentic automation & UI control: Follow complex multi-step instructions in browsers and desktop apps.
- Screenshot grounding: Perceive and act on the visual state of the screen.
- Tool calling: Native support for BrowserMCP and similar integrations.
- Error recovery: Maintain intermediate state and recover from minor execution errors.
- Long-horizon execution: Stable performance across many-step automation chains (up to 49 steps in a single turn).
Available Jan applications and platforms
mainJan is available across multiple platforms to suit different workflows:
- Desktop: A standalone application for local use.
- Browser: A web-based interface accessible via
https://chat.jan.ai/. - Browser Extension: (Coming soon).
- Jan Server: For server-side deployments and integrations.
Compare Jan with other ChatGPT alternatives
mainWhen choosing an alternative to ChatGPT, consider your requirements for privacy, offline access, and specific tasks. Jan is positioned as the best overall replacement because it supports both cloud and offline modes, is open-source, and supports agentic actions and MCP servers.
ChatGPT Alternative Offline Key Strength Best For Jan Yes Runs Cloud + Offline, open-source Best overall ChatGPT replacement Claude - Strong writing and reasoning Creative text & code Gemini - Integrated with Google Research tasks, image generation Perplexity - Fast, with cited answers Research and fact-checking LM Studio Yes Runs open models on PC Coding and experiments Core features of Jan
mainJan is an open-source ChatGPT replacement designed for privacy and local control. Key capabilities include:
- Local AI Models: Download and run LLMs (Llama, Gemma, Qwen, GPT-oss, etc.) directly from HuggingFace.
- Cloud Integration: Connect to remote models via OpenAI (GPT), Anthropic (Claude), Mistral, Groq, and more.
- Custom Assistants: Create specialized AI assistants for specific tasks.
- OpenAI-Compatible API: Run a local server at
localhost:1337that follows the OpenAI API specification, allowing other applications to call your local models. - Model Context Protocol (MCP): Integration with MCP for agent automation capabilities.
- Privacy First: All content can run entirely locally.
Key features of Jan
mainJan is an open-source ChatGPT replacement that provides full control and privacy. Key features include:
- Local AI Models: Download and run LLMs (Llama, Gemma, Qwen, GPT-oss, etc.) from HuggingFace.
- Cloud Integration: Connect to GPT models via OpenAI, Claude via Anthropic, Mistral, Groq, MiniMax, and more.
- Custom Assistants: Create AI assistants specialized for specific tasks.
- OpenAI Compatible API: Provides a local server at
localhost:1337for use with other applications. - Model Context Protocol (MCP): Integration for agentic capabilities.
- Privacy First: Run everything locally if required.
Overview of Lucy model
mainLucy is a compact 1.7B parameter model built on Qwen3-1.7B, specifically optimized for web search via tool calling. It is designed to work effectively with search APIs like Serper, making it suitable for resource-constrained environments where web search capabilities are needed.
Key Strengths:
- Web Search Integration: Optimized for calling search tools and processing results.
- Small Footprint: Low memory requirements due to its 1.7B parameter size.
- Tool Calling: Reliable function calling for search APIs.
What is Model Context Protocol (MCP) in Jan?
mainThe Model Context Protocol (MCP) is an open standard that allows AI models to interact with external tools and data sources through a standardized interface.
Jan acts as an MCP host, meaning it can connect to various MCP-compliant clients and servers. This allows your AI assistant to:
- Read & Understand: View local files, documents, folders, and databases.
- Take Actions: Search for information, create content, or run commands via web services (like GitHub or Slack).
- Use Templates: Execute common tasks and workflows.
By using MCP, you avoid the need for custom integrations for every new tool, as any MCP-compliant tool can interface with any MCP-compliant model.
Introduction to GPU kernels and benchmarking
mainIn GPU programming, a kernel is a piece of CUDA code designed to execute a sequence of operations on the GPU. Kernels are launched within a thread block grid, which executes the code across multiple Streaming Multiprocessors (SMs) on the GPU.
Benchmarking is used to quantitatively compare kernel performance across different problem sizes and to understand how hyperparameters impact execution speed. Accurate benchmarking is critical because GPU execution is complex and prone to measurement errors.
Recommended Tools for Accurate Measurement: If you require high-fidelity measurements of kernel characteristics, it is recommended to use official NVIDIA tools from the CUDA Toolkit rather than custom scripts:
- Nsight CUDA Profiling Tools Interface (cupti)
- Nsight Compute CLI (
ncu)
Overview of Jan models
mainJan uses a family of specialized models optimized for autonomous agentic tasks (planning, executing, and completing tasks over long horizons):
- Jan-v2: A multimodal agent designed for long-horizon tasks.
- Jan-v1: A model equipped with web search capabilities.
- Ichigo: A speech AI model specifically for voice interactions.
Understand Cortex's privacy and data handling
mainCortex is a library used to run large language models (LLMs) locally on your computer. It does not collect any personal information.Use native web_search and web_fetch tools
mainJan v0.8.4 introduces built-inweb_searchandweb_fetchtools powered bytauri-plugin-websearch. These tools allow models to search the internet and retrieve page content directly within the agent loop without requiring an external MCP (Model Context Protocol) server configuration.