# dify-mcp-client `MCP Client` as Agent Strategy Plugin with Computer Using Agent (UI-TARS-SDK) support. > [!IMPORTANT] > Dify is not `MCP Server` but `MCP Host`. ![showcase1](./_assets/arxiv_mcp_server_test.png) ## How it works Each `MCP client` (ReAct Agent) node can connect `MCP servers`. 1. `Tool`, `Resource`, `Prompt` lists are converted into Dify Tools. 2. Your selected LLM can see their `name`, `description`, `argument type` 3. The LLM calls Tools based on the ReAct loop (Reason → Act → Observe). > [!NOTE] > Most of the code in this repository contains the following files. > #### Dify Official Plugins / Agent Strategies > https://github.com/langgenius/dify-official-plugins/tree/main/agent-strategies/cot_agent ## ✅ What I did - Copied `ReAct.py` and renamed file as `mcpReAct.py` - Added `config_json` GUI input field by editing `mcpReAct.yaml` and `class mcpReActParams()` ### in mcpReAct.py, I added - New 12 functions for MCP - `__init__()` for initializing `AsyncExitStack` and `event loop` - Some codes in `_handle_invoke_action()` for MCP - MCP setup and cleanup in `_invoke()` > [!IMPORTANT] > ReAct while loop is as they are ## 🔄 Update history - Add SSE MCP client (v0.0.2) - Support multi SSE servers (v0.0.3) - Update python module and simplify its dependency (v0.0.4) - mcp(v1.1.2→v1.6.0+) - dify_plugin(0.0.1b72→v0.1.0) - Add UI-TARS SDK integration for GUI automation capabilities (v0.0.5) - Support Streamable HTTP MCP client - Feat SSE param: `/sse?key=value` (v0.0.6) ## 🤖 UI-TARS Integration This plugin includes [UI-TARS SDK](https://github.com/bytedance/UI-TARS-desktop/blob/main/docs/sdk.md) integration for GUI automation capabilities. > [!WARNING] > UI-TARS-SDK integration is supported only Dify Plugin's local debug deployment. > https://github.com/3dify-project/dify-mcp-client#-how-to-develop-and-deploy-plugin > > Normal difypkg install doesn't work. Because UI-TARS require OS native API, yet Dify plugin env is Linux docker container. > > I'm thinking alternative solusion via Streamable HTTP MCP. ### Key Features - **On-demand GUI automation**: UI-TARS is called only when needed, reducing token consumption - **Life-time control**: Set maximum loop count per task to prevent runaway automation ### Known Limitations - **Single Monitor Support**: UI-TARS currently recognizes the primary monitor only. Multi-monitor setups are not supported. - **Mac Retina Display Issue**: On macOS with Retina displays, UI-TARS requires the display resolution to be set to "Default" instead of the highest quality setting. Otherwise wrong (w,h) point is clicked. https://github.com/bytedance/UI-TARS-desktop/issues/591 ### Life-time Parameter The `life_time` parameter controls the maximum number of GUI actions UI-TARS can perform: - Default: 10 iterations - User-configurable maximum via `ui_tars_max_life_time_count` - Your selected LLM can dynamically adjust within the user-defined limit based on task complexity > [!NOTE] > Currently hardcoded to use UI-TARS-1.5-7B model for optimal cost-performance balance. ## 🐳 Docker Deployment with Pre-built Node.js ### Building the Docker Image

This pulldown guide is for TypeScript stdio MCP server user

```bash docker build -t dify-mcp-client:latest . ``` Or use our pre-built image: ```yaml # In your docker-compose.yml services: plugin-daemon: image: memedayo/dify-plugin-daemon:latest # with Pre-built Node.js # ... rest of configuration ``` Without Node.js in container, you lose TypeScript stdio MCP support.

### UI-TARS Configuration For detailed UI-TARS setup, refer to the [UI-TARS Desktop deployment guide](https://github.com/bytedance/UI-TARS/blob/main/README_deploy.md). The plugin automatically configures UI-TARS as a tool within the ReAct loop. You need to provide: - Hugging Face Inference Endpoint URL - API Key like (hf_xxxxx) - (Optional) Adjust `ui_tars_max_life_time_count` in agent parameters ## ⚠️ Caution and Limitation > [!CAUTION] > This plugin does **not** implement a **human-in-the-loop** mechanism by default, so connect **reliable mcp server only**.
> To avoid it, decrease `max itereations`(default:`3`) to `1`, and use this Agent node repeatedly in Chatflow.
> However, agent memory is reset by the end of Workflow.
> Use `Conversaton Variable` to save history and pass it to QUERY. > Don't forget to add a phrase such as > *"ask for user's permission when calling tools"* in INSTRUCTION. # How to use this plugin ## 🛜Install the plugin from GitHub - Enter the following GitHub repository name ``` https://github.com/3dify-project/dify-mcp-client/ ``` - Dify > PLUGINS > + Install plugin > INSTALL FROM > GitHub ![difyUI1](./_assets/plugin_install_online.png) ## ⬇️Install the plugin from .difypkg file - Go to Releases https://github.com/3dify-project/dify-mcp-client/releases - Select suitable version of `.difypkg` - Dify > PLUGINS > + Install plugin > INSTALL FROM > Local Package File ![difyUI2](./_assets/plugin_install_offline.png) ## How to handle errors when installing plugins? **Issue**: If you encounter the error message: `plugin verification has been enabled, and the plugin you want to install has a bad signature`, how to handle the issue?
**Solution**: Open `/docker/.env` and change from `true` to `false`: ``` FORCE_VERIFYING_SIGNATURE=false ``` Run the following commands to restart the Dify service: ```bash cd docker docker compose down docker compose up -d ``` Once this field is added, the Dify platform will allow the installation of all plugins that are not listed (and thus not verified) in the Dify Marketplace. ## Where does this plugin show up? - It takes few minutes to install - Once installed, you can use it any workflows as Agent node - Select "mcpReAct" strategy (otherwise no MCP) ![asAgentStrategiesNode](./_assets/asAgentStrategiesNode.png) ## Config MCP Agent Plugin node require config_json like this to command or URL to connect MCP servers ``` { "mcpServers":{ "name_of_server1":{ "url": "http://host.docker.internal:8080/sse" }, "name_of_server2":{ "url": "http://host.docker.internal:8008/mcp" } } } ``` > [!WARNING] > - Each server's port number should be different, like 8080, 8008, ... > - If you want to use stdio mcp server, there are 3 ways. > 1. Convert it to Streamable HTTP mcp server using mcp-proxy https://github.com/sparfenyuk/mcp-proxy?tab=readme-ov-file#1-stdio-to-ssestreamablehttp > 2. Deploy with source code (**NOT** by .difypkg or GitHub reposity name install) https://github.com/3dify-project/dify-mcp-client/edit/main/README.md#-how-to-develop-and-deploy-plugin > 3. Pre-install Node.js inside dify-plugin docker (Only TypeScript stdio server) ## Chatflow Example ![showcase2](./_assets/everything_mcp_server_test_resource.png) > [!WARNING] > - The Tools field should not be left blank. so **select Dify tools** like "current time". #### I provide this Dify ChatFlow `.yml` for testing this plugin. https://github.com/3dify-project/dify-mcp-client/tree/main/test/chatflow #### After download DSL(yml) file, import it in Dify and you can test MCP using "Everything MCP server" https://github.com/modelcontextprotocol/servers/tree/main/src/everything # How to convert stdio MCP server into Stremable HTTP (or SSE) ## option1️⃣: Edit MCP server's code If fastMCP server, change like this ```diff if __name__ == "__main__": - mcp.run(transport="stdio") + mcp.run(transport="streamable-http") ``` ## option2️⃣: via mcp-proxy > [!WARNING] > Streamable HTTP is recommended instead of deprecated SSE > Following old SSE setup doesn't work. Read https://github.com/sparfenyuk/mcp-proxy instead.

SSE setup (NOT Streamable HTTP)

``` \mcp-proxy>uv venv -p 3.12 .venv\Scripts\activate uv tool install mcp-proxy ``` ### Check Node.js has installed and npx(.cmd) Path (Mac/Linux) ``` which npx ``` (Windows) ``` where npx ``` result ``` C:\Program Files\nodejs\npx C:\Program Files\nodejs\npx.cmd C:\Users\USER_NAME\AppData\Roaming\npm\npx C:\Users\USER_NAME\AppData\Roaming\npm\npx.cmd ``` If claude_desktop_config.json is following schema, ``` { "mcpServers": { "SERVER_NAME": { "command": CMD_NAME_OR_PATH "args": {VALUE1, VALUE2} } } } ``` ### Wake up stdio MCP server by this command ``` mcp-proxy --sse-port=8080 --pass-environment -- CMD_NAME_OR_PATH --arg1 VALUE1 --arg2 VALUE2 ... ``` If your OS is Windows, use npx.cmd instead of npx. Following is example command to convert stdio "everything MCP server" to SSE via mcp-proxy. ``` mcp-proxy --sse-port=8080 --pass-environment -- C:\Program Files\nodejs\npx.cmd --arg1 -y --arg2 @modelcontextprotocol/server-everything ``` Similarly, on another command line (If you use sample Chatflow for v0.0.3) ``` pip install mcp-simple-arxiv mcp-proxy --sse-port=8008 --pass-environment -- C:\Users\USER_NAME\AppData\Local\Programs\Python\Python310\python.exe -m -mcp_simple_arxiv ``` Following is a mcp-proxy setup log. ``` (mcp_proxy) C:\User\USER_NAME\mcp-proxy>mcp-proxy --sse-port=8080 --pass-environment -- C:\Program Files\nodejs\npx.cmd --arg1 -y --arg2 @modelcontextprotocol/server-everything DEBUG:root:Starting stdio client and SSE server DEBUG:asyncio:Using proactor: IocpProactor DEBUG:mcp.server.lowlevel.server:Initializing server 'example-servers/everything' DEBUG:mcp.server.sse:SseServerTransport initialized with endpoint: /messages/ INFO: Started server process [53104] INFO: Waiting for application startup. INFO: Application startup complete. INFO: Uvicorn running on http://127.0.0.1:8080 (Press CTRL+C to quit) ```

# 🔨 How to develop and deploy plugin ### Official plugin dev guide https://github.com/3dify-project/dify-mcp-client/blob/main/GUIDE.md ### Dify plugin SDK daemon If your OS is Windows and CPU is Intel or AMD, you need to download the latest `dify-plugin-windows-amd64.exe`
Choose your OS-compatible verson here:
https://github.com/langgenius/dify-plugin-daemon/releases
1. Rename it as dify.exe for convinence 2. mkdir "C\User\user\\.local\bin" (Windows) and register it as system path. 3. Copy `dify.exe` to under dify-mcp-client/ > [!TIP] > Following guide is helpful. > https://docs.dify.ai/plugins/quick-start/develop-plugins/initialize-development-tools ### Reference https://docs.dify.ai/plugins/quick-start/develop-plugins/initialize-development-tools > [!NOTE] > You can skip this stage if you pull or download codes of this repo > ``` > dify plugin init > ``` > Initial settings are as follow > ![InitialDifyPluginSetting](./_assets/initial_mcp_plugin_settings.png) ### Change directory ``` cd dify-mcp-client ``` ### Install python module Python3.12+ is compatible. The `venv` and `uv` are not necessary, but recommended. ``` uv venv -p 3.12 .venv\Scripts\activate ``` Install python modules for plugin development ``` uv pip install -r requirements.txt ``` For only UI-TARS-SDK user (after installing Node.js v22 LTS) ``` npm install ``` ### Duplicate `env.example` and rename one to `.env` I changed `REMOTE_INSTALL_HOST` from `debug.dify.ai` to `localhost` (Docker Compose environment) click 🪲bug icon button to see these information ### Activate Dify plugin ``` python -m main ``` (ctrl+C to stop) > [!TIP] > REMOTE_INSTALL_KEY of .env often changes. > If you encounter error messages like `handshake failed, invalid key`, renew it. ### Package into .difypkg `./dify-mcp-client` is my default root name ``` dify plugin package ./ROOT_OF_YOUR_PROJECT ``` ## Useful GitHub repositories for developers #### Dify Plugin SDKs https://github.com/langgenius/dify-plugin-sdks #### MCP Python SDK https://github.com/modelcontextprotocol/python-sdk
> [!TIP] > MCP client example
> https://github.com/modelcontextprotocol/python-sdk/blob/main/examples/clients/simple-chatbot/mcp_simple_chatbot/main.py
> [!NOTE] > Dify plugin has `requirements.txt` which automatically installs python modules.
> I include latest `mcp` in it, so you don't need to download the MCP SDK separately.

Dify Mcp Client

Install

Dify Mcp Client

Install