CopilotChat GlobFile Configuration

Want to feed multiple files into GitHub Copilot Chat from Neovim without listing each one manually? Let's add a tiny feature that does exactly that: a file glob that includes full file contents. In this post, we'll walk through what CopilotChat.nvim offers out of the box, why the missing piece matters, and how to implement a custom #file_glob:<pattern> function to include the contents of all files matching a glob.

Using Copilot Chat with Neovim

CopilotChat.nvim brings GitHub Copilot's chat right into your editing flow. No context switching, no browser hopping — just type your prompt in a Neovim buffer and let the AI help you refactor code, write tests, or explain tricky functions.

You can open the chat (for example) with a command like :CopilotChat, then provide extra context using built-in functions. That “extra context” is where the magic really happens.

Built-in functions in CopilotChat.nvim

Inside the chat window, you can inject context using special functions. Two handy ones are:

• #file:<filename> — includes the full contents of that file.
• #glob:<pattern> — expands to a list of filenames matching a pattern (filenames only, not contents).

For example, you could paste multiple files with:

#file:src/main.ts
#file:src/utils/strings.ts
#file:src/utils/dates.ts

Or you can ask Copilot to consider filenames that match a glob (again, names only):

#glob:src/**/*.ts

That's useful, but sometimes you really need the content of a bunch of files at once. Enter the missing piece.

The missing piece: #file_glob:<pattern>

We want to write something like:

#file_glob:src/**/*.ts

and have CopilotChat include the full contents of every matching file. This is incredibly convenient when you're:

• Refactoring a feature that spans multiple files.
• Writing tests across a directory.
• Porting utilities from one folder to another.

CopilotChat.nvim doesn't ship this function by default, but the plugin is extensible, so we can add it ourselves in just a few lines of Lua.

Implementation: add file_glob to CopilotChat

Drop the following into your CopilotChat.nvim setup (for example, inside your plugin manager config). It extends the existing functions with a new one called file_glob that gathers files via a glob and returns their contents as resources for the chat.

local file_glob_function = {
  file_glob = {
    group = 'copilot',
    uri = 'files://glob_contents/{pattern}',
    description = 'Includes the full contents of every file matching a specified glob pattern.',
    schema = {
      type = 'object',
      required = { 'pattern' },
      properties = {
        pattern = {
          type = 'string',
          description = 'Glob pattern to match files.',
          default = '**/*',
        },
      },
    },
    resolve = function(input, source)
      local files = require('CopilotChat.utils.files').glob(source.cwd(), {
        pattern = input.pattern,
      })

      local resources = {}
      for _, file_path in ipairs(files) do
        local data, mimetype = require('CopilotChat.resources').get_file(file_path)
        if data then
          table.insert(resources, {
            uri = 'file://' .. file_path,
            name = file_path,
            mimetype = mimetype,
            data = data,
          })
        end
      end

      return resources
    end,
  },
}

require("CopilotChat").setup {
  -- other configuration
  functions = vim.tbl_deep_extend('force', require("CopilotChat.config.functions"), file_glob_function),
  -- other configuration
}

What this does

• Extends the plugin's functions with file_glob, which:
  • Finds files using the provided pattern (relative to the workspace root).
  • Loads each file's content and MIME type.
  • Returns a list of resources that CopilotChat will attach to your conversation.

How to use #file_glob in chat

Inside an open Copilot Chat buffer, type a prompt and include a glob pattern. A few examples:

Please review the following TypeScript utils and suggest a common refactor.
#file_glob:src/utils/**/*.ts

Generate Jest tests for all reducers.
#file_glob:src/store/**/reducers/*.ts

Summarize the docs.
#file_glob:docs/**/*.md

Patterns are typically relative to your project root. Keep them as specific as possible to avoid pulling in huge numbers of files.

Tips, caveats, and troubleshooting

• Token budgets are real: Including dozens of large files can exceed model context limits. Prefer narrower globs like src/**/parser/*.ts over project-wide patterns.
• Binary or large files: The resolver reads file contents. If you match binaries or huge assets, you'll waste tokens and time. Use patterns that target source code (e.g., **/*.ts, **/*.py, **/*.lua).
• Nothing happens? Verify your pattern is correct relative to the project root.
• De-duplication is built-in: The resolver won't attach the same file twice.
• Performance: If the glob is very broad (like **/*), it may scan a lot of files. Narrow it down to the folder or extension you actually need.

Wrapping up

With a small extension, CopilotChat.nvim becomes even more powerful for multi-file prompts. The custom #file_glob:<pattern> function lets you pull entire sets of files into context with a single line. It's a simple change with outsized impact on your day-to-day workflow.

Give it a try, tune your patterns, and enjoy a more fluid conversation with your code.