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Neovim Integration Guide

Complete guide to using Radium with Neovim via the radium-nvim extension.

Prerequisites​

  • Neovim 0.5+ (with Lua support)
  • Radium CLI installed and in PATH
  • Radium workspace initialized (optional, for some features)

Installation​

Step 1: Install the Extension​

rad extension install radium-nvim

Or from a local directory:

rad extension install ./extensions/radium-nvim

Step 2: Load the Plugin​

Add to your Neovim configuration (~/.config/nvim/init.lua or ~/.vimrc):

-- Load Radium plugin
require("radium")

Or if using a plugin manager like packer.nvim:

use({
    "radium/radium-nvim",
    config = function()
        require("radium")
    end
})

Commands​

:RadiumSendSelection

Sends the current visual selection to Radium for processing.

Usage:

  1. Select code in visual mode (v, V, or Ctrl-v)
  2. Run :RadiumSendSelection
  3. Code is sent to Radium with full context:
    • File path
    • Language/filetype
    • Selected code
    • Surrounding lines (for context)

Configuration:

-- Set default agent (defaults to "code-agent")
vim.g.radium_default_agent = "code-agent"

:RadiumChat​

Opens an interactive chat session with a Radium agent.

Usage:

:RadiumChat

This opens a split window with an integrated terminal running rad chat.

:RadiumApplyBlock​

Applies the last agent-generated code block to the current buffer.

Usage:

  1. After receiving agent output from :RadiumSendSelection
  2. Run :RadiumApplyBlock
  3. A diff preview is shown
  4. Press y to apply or n to cancel

Features:

  • Shows diff preview before applying
  • Handles multiple code blocks (prompts for selection)
  • Can replace selection or insert at cursor

Configuration​

Default Agent​

vim.g.radium_default_agent = "code-agent"

Environment Variables​

The extension automatically sets these environment variables for hooks:

  • RADIUM_EDITOR_FILE_PATH - Full path to current file
  • RADIUM_EDITOR_LANGUAGE - Filetype/language
  • RADIUM_EDITOR_SELECTION - Selected code
  • RADIUM_EDITOR_SURROUNDING_LINES - Context around selection

Hook Integration​

The extension includes two hooks that are automatically registered:

BeforeTool Hook (editor-context)​

Injects editor context before tool execution:

  • File path
  • Language identifier
  • Selected code
  • Surrounding lines

AfterTool Hook (code-apply)​

Processes agent output:

  • Extracts code blocks from markdown
  • Structures output for editor application
  • Adds metadata (language, line ranges)

Workflow Example​

  1. Select code:

    Visual mode: v
    Select function: jjj

  2. Send to Radium:

    :RadiumSendSelection

  3. Review output:

    • Agent response appears in split window
    • Review the suggested changes

  4. Apply changes:

    :RadiumApplyBlock
    • Diff preview appears
    • Press y to apply or n to cancel

Troubleshooting​

Commands not found​

Issue: :RadiumSendSelection command not available

Solution:

  • Verify extension is installed: rad extension list
  • Check plugin is loaded: :lua print(require("radium"))
  • Reload Neovim configuration

CLI not found​

Issue: Error about rad command not found

Solution:

  • Ensure Radium CLI is in PATH
  • Test: which rad or rad --version
  • Restart Neovim after installing CLI

Context not injected​

Issue: Agent doesn't receive file context

Solution:

  • Verify hooks are registered: Check extension installation
  • Check environment variables are set
  • Ensure file has a valid filetype set

Advanced Usage​

Custom Agent Selection​

You can specify a different agent per command by modifying the command:

vim.api.nvim_create_user_command('RadiumRefactor', function()
    vim.g.radium_default_agent = "refactor-agent"
    require('radium.commands').send_selection()
end, {})

Integration with Other Plugins​

The extension stores agent output in buffer-local variables, making it accessible to other plugins or custom Lua code:

local output = vim.b.radium_last_output
-- Process output as needed

See Also​