Update 2025-07-08

Gemini CLI supports HTTP-based MCP server integration

So, it’s possible to replace the .gemini/settings.json included in the original post with:

{
  "theme": "Default",
  "mcpServers": {
    "ackal-mcp-server": {
      "httpUrl": "http://localhost:7777/mcp",
      "timeout": 5000
    },
    "prometheus-mcp-server": {
      "httpUrl": "https://prometheus.{tailnet}/mcp",
      "timeout": 5000
    }
  },
  "selectedAuthType": "gemini-api-key"
}

This solution permits the addition of headers too for e.g. including Authorization

Original

Okay, so not “Gemini Code Assist” but sufficiently similar that I think it warrants the “3/3” appellation.

Solved!

Ugh.

Before I continue, one important detail from yesterday’s experience which I think I didn’t clarify is that, unlike the Copilot agent, it appears (!?) that Gemini agent only supports integration with MCP servers via stdio. As a result, the only way to integrate with HTTP-based MCP servers (local or remote) is to proxy traffic through stdio as mcp-remote and the Rust example herein.

The most helpful change was to take a hint from the NPM mcp-remote and create a log file. This helps because, otherwise the mcp-remote process, because it’s launched by Visual Studio Code, well Gemini Code Assist agent, isn’t trivial to debug.

Former Microsoftie and Googler:

Good documentation Extend your agent with Model Context Protocol

Not such good documentation: Using agentic chat as a pair programmer

Definition of “good” being, I was able to follow the clear instructions and it worked first time. Well done, Microsoft!

This space is moving so quickly and I’m happy to alpha test these companies’ solutions but (a) Google’s portfolio is a mess. This week I’ve tried (and failed) to use Gemini CLI (because I don’t want to run Node.JS on my host machine and it doesn’t work in a container: issue #1437) and now this.

I was unable to find a Model Context Protocol (MCP) server implementation for Prometheus. I had a quiet weekend and so I’ve been writing one: prometheus-mcp-server.

I used the code from the MCP for gRPC Health Checking protocol that I wrote about previously as a guide.

I wrote a series of stdin and HTTP tests to have confidence that the service is working correctly but I had no MCP host.

I discovered that Visual Studio Code through its GitHub Copilot extension functions has a preview to use MCP servers i.e. function as an MCP host and access MCP servers.

Model Context Protocol (MCP) is “all the rage” these days.

I stumbled upon protoc-gen-go-mcp and think it’s an elegant application of two technologies: programmatically generating an MCP server from a gRPC protobuf.

I’m considering building an MCP server for Ackal but, thought I’d start with something simple: gRPC Health Checking protocol.

I was surprised to learn as I was doing this that there’s a new List (Add List method to gRPC Health service #143) added to grpc.health.v1.Health. My (Ackal) healthcheck server does not yet implement it (see later).