Load different mcpservics.json for different projects

[nzlov]

Using different mcpservices.json files for different projects offers the following benefits:

Flexibility: Each project can independently configure service parameters, avoiding conflicts and meeting specific requirements.

Maintainability: Modifying one project's configuration won't affect others, making management and debugging easier.

Security: Sensitive information (e.g., API keys) can be isolated by project, reducing the risk of exposure.

Collaboration Efficiency: Team members can adjust configurations for specific projects without worrying about impacting workflows of other projects.

[nzlov]

{
        "ravitemer/mcphub.nvim",
        build = "npm install -g mcp-hub@latest", -- Installs required mcp-hub npm module
        config = function()
          math.randomseed()
          local cfg = function()
            local cwd_config = vim.fn.getcwd() .. "/mcpservers.json"
            if vim.fn.filereadable(cwd_config) == 1 then
              return cwd_config
            else
              return vim.fn.expand("~/mcpservers.json")
            end
          end

          require("mcphub").setup({
            -- Required options
            --port = 30000, -- Port for MCP Hub server
            port = math.random(50000, 50100), -- Port for MCP Hub server

            config = cfg(), -- Prioritize config in current directory, fall back to home

            -- Optional options
            on_ready = function(hub)
              -- Called when hub is ready
            end,
            on_error = function(err)
              -- Called on errors
            end,
            shutdown_delay = 0, -- Wait 0ms before shutting down server after last client exits
            log = {
              level = vim.log.levels.WARN,
              to_file = false,
              file_path = nil,
              prefix = "MCPHub",
            },
          })
        end,
      }

[ravitemer]

That's a nice idea. Thanks for sharing.

[arathunku]

I used similar approach with gemini generated lua code to have consistent port per project

local function generatePortFromString(inputString, minPort, maxPort)
  -- Calculate a simple numeric hash from the string bytes
  local hash = 0
  for i = 1, #inputString do
    -- Add the byte value of each character
    -- Multiply by a prime (31) and add to distribute values slightly better
    hash = (hash * 31 + string.byte(inputString, i)) % 2^32 -- Keep within integer limits
  end

  local rangeSize = maxPort - minPort + 1

  -- Map the hash to the desired port range using modulo
  local port = (hash % rangeSize) + minPort

  return port
end

Now my next mission is to detect cwd changes and restart/reload both port and config but it doesn't look like there's any API for that. Calling setup again with a different config will not reload the instance - https://github.com/ravitemer/mcphub.nvim/blob/main/lua/mcphub/init.lua#L24. @ravitemer would you be open to exposing additional API or a PR that will compare config/port and reload if it's not matching current instance values?

[ravitemer]

@arathunku Nice use case. I can see how this might be useful for some.

Although there is'nt a direct method for it, on first thoughts for you to test it out there is a hack, I think we can change the self.port and self.config of State.hub_instance which update the api_request method to point to this new port and then run hub_instance:start() which checks for the server running at the new port, if not present then it starts the mcp-hub with the new config file at the new port.

You can try it and let me know. Ideally we listen to "DirChanged" event and find servers.json file from that directory and decide the port based on the hash of the directory path like you are doing. Get the hub_instance and update the port,config and start(). I haven't tested it out but this might be a starting point for you.

I would like to support this but can't say when. Would very much like a PR if you decide to do it