This article explains how to configure CopilotChat to use a custom provider. CopilotChat is a NeoVim plugin that provides a LLM chat interface and real-time suggestions. Typically, you use CopilotChat with GitHub Copilot. However, it also supports custom providers. This is especially useful if you work a job where they forbid GitHub Copilot but provide internal LLM services.

Lazy Configuration

It’s assumed you’re using NeoVim with the Lazy plugin manager. Below is the Lazy configuration for CopilotChat with a custom provider.

{
  "CopilotC-Nvim/CopilotChat.nvim",
  branch = "main",
  event = "VeryLazy",
  dependencies = {
    { "github/copilot.vim" },
    { "nvim-lua/plenary.nvim" },
  },
  opts = {
    model = "gemma-4-31b-it", -- Update this to match the id of a provider model
    providers = {
      <COMPANY_NAME> = {
        get_url = function()
          return "<API_BASE_URL>/v1/chat/completions"
        end,
        get_headers = function()
          return {
            ["Authorization"] = "Bearer <YOUR_API_KEY>"),
          }
        end,
        get_models = function()
          return { { id = "gemma-4-31b-it", name = "Gemma 4-31B-it" } }
        end,
        prepare_input = function(data, dev)
          return require("CopilotChat.config.providers").copilot.prepare_input(data, dev)
        end,
        prepare_output = function(data, dev)
          return require("CopilotChat.config.providers").copilot.prepare_output(data, dev)
        end,
      },
    },
  }
}

There’s a couple fields that require adjustment on your end marked with <...> in the configuration:

• COMPANY_NAME: This is the name of your provider. You can choose any name you want, but it should be unique and descriptive.
• API_BASE_URL: This is the base address for your provider’s API. You’ll have to consult your provider’s docs to find out what this is.
• YOUR_API_KEY: This is the API key for your provider. Again, consult your provider’s docs to find out how to generate a user API key or a get an organization key.

The get_models() function is also of interest. Most providers have a catalog of LLMs that you can use. In the example, a single model called gemma-4-31b-it gets referenced. You can add as many models as you want from your provider’s catalog. Just make sure the id field matches the model name as defined by your provider.

Save and reload your configuration. If all goes well, you should see your providers’ models in the :CopilotChatModels menu.

Worth mentioning, there are more functions you can override in the provider interface provided by CopilotChat. For the full listing see Providers.