Jan

repository·main·Indexed 12 days ago

https://github.com/janhq/jan

An 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.

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What's inside Jan

  1. Overview of Jan AI

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    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.
  2. Overview of Jan-v2-VL Vision-Language Model

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    Jan-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

    VariantFocus
    Jan-v2-VL-lowEfficiency-oriented, lower latency
    Jan-v2-VL-medBalanced latency and quality
    Jan-v2-VL-highDeeper 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).
  3. Available Jan applications and platforms

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    Jan 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.
  4. Compare Jan with other ChatGPT alternatives

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    When 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 AlternativeOfflineKey StrengthBest For
    JanYesRuns Cloud + Offline, open-sourceBest overall ChatGPT replacement
    Claude-Strong writing and reasoningCreative text & code
    Gemini-Integrated with GoogleResearch tasks, image generation
    Perplexity-Fast, with cited answersResearch and fact-checking
    LM StudioYesRuns open models on PCCoding and experiments
  5. Core features of Jan

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    Jan 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:1337 that 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.
  6. Key features of Jan

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    Jan 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:1337 for use with other applications.
    • Model Context Protocol (MCP): Integration for agentic capabilities.
    • Privacy First: Run everything locally if required.
  7. Overview of Lucy model

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    Lucy 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.
  8. What is Model Context Protocol (MCP) in Jan?

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    The 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.

  9. Introduction to GPU kernels and benchmarking

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    In 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)
  10. Overview of Jan models

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    Jan 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.