Best for
- Developers needing to build or customize an AI chat interface.
- Teams looking to leverage MCP tools to enhance model capabilities.
- Developers familiar with the Hugging Face ecosystem seeking quick deployment.
Chat UI is a powerful open-source chat interface focused on OpenAI-compatible APIs, with built-in MCP tool support. It is suitable for developers needing to quickly build custom AI chat fronts, but attention must be paid to API key management and external dependency risks.
Strongest · Documentation 14/20 Weakest · Reliability 3/20
Static review · not runListed 2026-08-07
Read the FMRS scoring method →Runtime:Node.js · Docker
OPENAI_BASE_URL
Base URL of any OpenAI-compatible API (e.g. https://router.huggingface.co/v1); models are discovered via its /models endpoint.
OPENAI_API_KEY
Key for the OpenAI-compatible endpoint, e.g. hf_xxx (Hugging Face access token); HF_TOKEN is a legacy alias.
HF_TOKEN
Legacy alias for OPENAI_API_KEY, still accepted.
MONGODB_URL
MongoDB connection string; if unset, an embedded MongoDB persists to ./db.
MONGODB_DB_NAME
Database name, defaults to chat-ui.
MCP_SERVERS
JSON array of preconfigured MCP servers (name, url, optional headers) serving as the base list for all users.
MCP_FORWARD_HF_USER_TOKEN
Set to true to forward the signed-in user's Hugging Face token to the official HF MCP login endpoint when that server entry has no Authorization header.
LLM_ROUTER_ROUTES_PATH
Path to your own routes-policy JSON array (each entry needs name, description, primary_model, optional fallback_models).
LLM_ROUTER_DEFAULT_ROUTE
Default route name for the Omni router, defaults to default.
LLM_ROUTER_FALLBACK_MODEL
Fallback model when all models in the selected route fail.
LLM_ROUTER_ENABLE_MULTIMODAL
Set to true so image inputs bypass the policy file and go to the multimodal model.
LLM_ROUTER_MULTIMODAL_MODEL
Target model for the multimodal route.
LLM_ROUTER_ENABLE_TOOLS
Set to true so requests with an MCP server enabled take the agentic route.
LLM_ROUTER_TOOLS_MODEL
Tools-capable target model that must support OpenAI function calling.
PUBLIC_LLM_ROUTER_ALIAS_ID
Alias ID of the virtual Omni model, defaults to omni.
PUBLIC_LLM_ROUTER_DISPLAY_NAME
Display name shown in the UI for the Omni alias, defaults to Omni.
PUBLIC_LLM_ROUTER_LOGO_URL
Optional logo URL for the Omni alias.
PUBLIC_APP_NAME
App title used throughout the UI.
PUBLIC_APP_ASSETS
Folder under static/ for logos and favicons (chatui or huggingchat).
PUBLIC_APP_DESCRIPTION
App description text.
PUBLIC_APP_DATA_SHARING
Set to 1 to add a user-settings toggle for opting in to data sharing with model creators.
To use this MCP server, you need to clone the Chat UI repository and configure environment variables.
git clone https://github.com/huggingface/chat-uicd chat-ui.env.local, set OPENAI_BASE_URL and OPENAI_API_KEY. For example:OPENAI_BASE_URL=https://router.huggingface.co/v1
OPENAI_API_KEY=hf_xxxnpm installnpm run dev -- --openNote: MCP server support is not a standalone installation; it is built into Chat UI. You do not need to install a separate MCP server package.
After starting the app, open "MCP Servers" from the top-right menu or the + menu in the chat input, add a server, and run Health Check; a passing health check and a tool list on the server card confirm the MCP connection works.
Once connected, you can ask your AI assistant things like:
No matching tools
Listed from the project's documentation, not tested by this site.
Chat UI is a chat interface for large language models, built with SvelteKit and powering HuggingChat. It only supports OpenAI-compatible APIs, configured via environment variables. Chat UI can connect to various OpenAI-compatible endpoints such as Hugging Face Inference Providers, llama.cpp, Ollama, OpenRouter, etc. It also integrates MCP (Model Context Protocol) tools, allowing models to call external tools. This MCP server provides MCP support for Chat UI, enabling it to act as an MCP client.
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Source revision 8e696f8877ca Data synced 2026-10-12 Read the FMRS scoring method