SearXNG MCP Server

A SearXNG search MCP service implemented based on FastMCP, using Streamable HTTP transport, supporting local running and Docker deployment.

SearXNG related links:

Official documentation: https://docs.searxng.org/

Online example: https://searx.space/

Features

• Exposes the MCP tool search(query): calls the SearXNG instance based on keywords and returns a summary of search results.

• Provides the MCP service via the HTTP endpoint http://<host>:<port>/mcp, making it easy for remote/cross-domain calls.

• Uses stateless Streamable HTTP mode; clients do not need to maintain Mcp-Session-Id and can make concurrent calls directly.

• Supports customizing the SearXNG instance address via environment variables, making private deployment easy.

Related MCP server: searxng-mcp-server

Environment Variables

Local Run

# 安装依赖（建议使用虚拟环境）
pip install -r requirements.txt

# 可选：自定义 SearXNG 实例（只需填根地址）
export SEARXNG_URL="https://your-searxng-instance"

# 启动服务
python Server.py

After startup, the MCP endpoint is:

http://localhost:9000/mcp

Docker Deployment

Build Image

docker build -t searxng-mcp .

Run Container

docker run -d \
  --name searxng-mcp \
  -p 9000:9000 \
  -e SEARXNG_URL="https://searxng.abc.com" \
  searxng-mcp

To change the port, you can override both the container's internal and external ports and PORT:

docker run -d \
  --name searxng-mcp \
  -p 8080:8080 \
  -e PORT=8080 \
  searxng-mcp

Using the online image

docker run -d \
  --name searxng-mcp \
  -p 9000:9000 \
  -e SEARXNG_URL="https://searxng.abc.com" \
  muzihuaner/searxng-mcp:latest

Access Address

After deployment, the MCP endpoint format is:

http://<你的服务器域名或IP>:<端口>/mcp

For example: http://localhost:9000/mcp or https://mcp.your-domain.com/mcp

Client Configuration

In an MCP client that supports Streamable HTTP, fill in the service address as the /mcp endpoint above, for example:

{
  "mcpServers": {
    "searxng": {
      "url": "http://localhost:9000/mcp"
    }
  }
}

Tool Description

search(query: str) -> str

Calls SearXNG search based on keywords and returns the content text of each result entry, joined by newlines.

• query: search keyword.

• Returns: the text content of the search results; returns False if the request fails.

Concurrency and Performance

测试结果示例（局域网 / 上游 `so.xxx.cn`）：

总请求数 : 100 并发 worker : 50 成功 : 100 失败 : 0 总耗时(秒) : 67.68 吞吐(QPS) : 1.48 平均延迟(秒) : 27.284 最小延迟(秒) : 7.203 最大延迟(秒) : 44.418

> 注意：端到端延迟主要取决于 SearXNG 上游实例的响应速度（本例平均约 27s 来自上游 `so.xxx.cn` 较慢），服务本身可稳定承载并发且零失败。若需提升吞吐，可：
> - 换用响应更快 / 自托管的 SearXNG 实例（通过 `SEARXNG_URL` 指定）；

FAQ

Q: Client reports error Missing session ID? A: This service has stateless_http=True enabled, so no session is needed. If the error persists, please confirm that the client points to the /mcp endpoint.

Q: How to tighten CORS in production? A: Edit the CORSMiddleware in Server.py and change allow_origins=["*"] to a specific origin list, such as ["https://your-domain.com"].