Using Tidewave with MCP proxy (deprecated)

DEPRECATED: use the new MCP Proxy written in Rust: https://elixirdrops.net/d/UAo4BtYi.

If you’ve set up Tidewave as described in Setting up Tidewave in your Phoenix app, but it doesn’t seem reliable, you might want to try using it with MCP Proxy.

# Install mcp_proxy escript
mix escript.install hex mcp_proxy

# Get the escript and mcp-proxy paths
which escript
which mcp-proxy

# Update `.cursor/mcp.json`
{
  "mcpServers": {
    "tidewave": {
      "command": "<ESCRIPT PATH>",
      "args": [
        "<MCP PROXY PATH>",
        "http://localhost:4000/tidewave/mcp"
      ]
    }
  }
}

In my case, .cursor/mcp.json looks like this:

{
  "mcpServers": {
    "tidewave": {
      "command": "~/.local/share/mise/installs/erlang/27.2.3/bin/escript",
      "args": [
        "~/.local/share/mise/installs/elixir/1.18.2-otp-27/.mix/escripts/mcp-proxy",
        "http://localhost:4000/tidewave/mcp"
      ]
    }
  }
}

You shouldn’t see errors in the Cursor MCP configuration anymore.

Credits: https://github.com/tidewave-ai/tidewave_phoenix/issues/19#issuecomment-2840300011