# Using ui-mcp-proxy in Llama-cpp

> Source: <https://www.dotnetperls.com/2026_7_26_using-ui-mcp-proxy-llama-cpp>
> Published: 2026-07-26 07:00:00+00:00

Yesterday I developed a simple **MCP server**, which allows local LLMs to call tools that I have written in Rust code. This worked well, but I ran into **CORS errors**—CORS is a security feature on web browsers. I found that `llama-cpp`

has a special feature to avoid these issues.

With `ui-mcp-proxy`

, passed as an **argument** to `llama-server`

, a proxy server is set up so that the MCP server is on the same server as `llama-cpp`

. This **eliminates** the CORS errors altogether.

I was able to remove the middleware logic that set up CORS headers—it wasn't a huge win, but anything that **simplifies code** is a **benefit**. After all, code is a burden and having the minimal amount of necessary code will make life easier.

According to the Model Context Protocol specification, **JSON-encoded messages** must be used, so there will always be some complexity due to decoding and encoding messages. That is essential complexity here.