feat: add ClaudeCodeTreeAdd command for tree integration

- Add integrations.lua module to handle nvim-tree and neo-tree file selection
- Add ClaudeCodeTreeAdd command to send file at_mentions from tree explorers
- Support both single file selection and multi-file selection
- Update README with tree integration documentation and lazy.nvim keybinding setup
- Implement context-aware <leader>as keybinding behavior

Co-authored-by: ThomasK33 <[email protected]>

Author: blink-so[bot]

README.md

@@ -51,6 +51,8 @@ Using [lazy.nvim](https://github.com/folke/lazy.nvim):
   keys = {
     { "<leader>ac", "<cmd>ClaudeCode<cr>", desc = "Toggle Claude" },
     { "<leader>as", "<cmd>ClaudeCodeSend<cr>", mode = "v", desc = "Send to Claude" },
+    -- Add file from nvim-tree or neo-tree
+    { "<leader>as", "<cmd>ClaudeCodeTreeAdd<cr>", desc = "Add file to Claude context", ft = { "NvimTree", "neo-tree" } },
   },
 }
 ```
@@ -60,13 +62,35 @@ That's it! For more configuration options, see [Advanced Setup](#advanced-setup)
 ## Usage
 
 1. **Launch Claude**: Run `:ClaudeCode` to open Claude in a split terminal
-2. **Send context**: Select text and run `:'<,'>ClaudeCodeSend` to send it to Claude
+2. **Send context**: 
+   - Select text in visual mode and use `<leader>as` to send it to Claude
+   - In `nvim-tree` or `neo-tree`, press `<leader>as` on a file to add it to Claude's context
 3. **Let Claude work**: Claude can now:
    - See your current file and selections in real-time
    - Open files in your editor
    - Show diffs with proposed changes
    - Access diagnostics and workspace info
 
+## Commands
+
+- `:ClaudeCode` - Toggle the Claude Code terminal window
+- `:ClaudeCodeSend` - Send current visual selection to Claude
+- `:ClaudeCodeTreeAdd` - Add selected file(s) from tree explorer to Claude context
+
+### Tree Integration
+
+The `<leader>as` keybinding has context-aware behavior:
+- **In normal buffers (visual mode)**: Sends selected text to Claude
+- **In nvim-tree/neo-tree buffers**: Adds the file under cursor (or selected files) to Claude's context
+
+This allows you to quickly add entire files to Claude's context for review, refactoring, or discussion.
+
+#### Features:
+- **Single file**: Place cursor on any file and press `<leader>as`
+- **Multiple files**: Select multiple files (using tree plugin's selection features) and press `<leader>as`
+- **Smart detection**: Automatically detects whether you're in nvim-tree or neo-tree
+- **Error handling**: Clear feedback if no files are selected or if tree plugins aren't available
+
 ## How It Works
 
 This plugin creates a WebSocket server that Claude Code CLI connects to, implementing the same protocol as the official VS Code extension. When you launch Claude, it automatically detects Neovim and gains full access to your editor.

lua/claudecode/init.lua

@@ -292,6 +292,57 @@ function M._create_commands()
     range = true, -- Important: This makes the command expect a range (visual selection)
   })
 
+  vim.api.nvim_create_user_command("ClaudeCodeTreeAdd", function()
+    if not M.state.server then
+      logger.error("command", "ClaudeCodeTreeAdd: Claude Code integration is not running.")
+      vim.notify("Claude Code integration is not running", vim.log.levels.ERROR)
+      return
+    end
+
+    local integrations = require("claudecode.integrations")
+    local files, error = integrations.get_selected_files_from_tree()
+    
+    if error then
+      logger.warn("command", "ClaudeCodeTreeAdd: " .. error)
+      vim.notify(error, vim.log.levels.WARN, { title = "ClaudeCode" })
+      return
+    end
+    
+    if not files or #files == 0 then
+      logger.warn("command", "ClaudeCodeTreeAdd: No files selected")
+      vim.notify("No files selected", vim.log.levels.WARN, { title = "ClaudeCode" })
+      return
+    end
+    
+    -- Send each file as an at_mention (full file, no line numbers)
+    local success_count = 0
+    for _, file_path in ipairs(files) do
+      local params = {
+        filePath = file_path,
+        lineStart = nil,  -- No line numbers for full file
+        lineEnd = nil     -- No line numbers for full file
+      }
+      
+      local broadcast_success = M.state.server.broadcast("at_mentioned", params)
+      if broadcast_success then
+        success_count = success_count + 1
+        logger.debug("command", "ClaudeCodeTreeAdd: Added file " .. file_path)
+      else
+        logger.error("command", "ClaudeCodeTreeAdd: Failed to add file " .. file_path)
+      end
+    end
+    
+    if success_count > 0 then
+      local message = success_count == 1 
+        and "Added 1 file to Claude context" 
+        or string.format("Added %d files to Claude context", success_count)
+      vim.notify(message, vim.log.levels.INFO, { title = "ClaudeCode" })
+    else
+      vim.notify("Failed to add any files", vim.log.levels.ERROR, { title = "ClaudeCode" })
+    end
+  end, {
+    desc = "Add selected file(s) from tree explorer to Claude Code context",
+  })
 
   local terminal_ok, terminal = pcall(require, "claudecode.terminal")
   if terminal_ok then

lua/claudecode/integrations.lua

@@ -0,0 +1,118 @@
+---
+-- Tree integration module for ClaudeCode.nvim
+-- Handles detection and selection of files from nvim-tree and neo-tree
+-- @module claudecode.integrations
+local M = {}
+
+local logger = require("claudecode.logger")
+
+--- Get selected files from the current tree explorer
+--- @return table|nil files List of file paths, or nil if error
+--- @return string|nil error Error message if operation failed
+function M.get_selected_files_from_tree()
+  local current_ft = vim.bo.filetype
+  
+  if current_ft == "NvimTree" then
+    return M._get_nvim_tree_selection()
+  elseif current_ft == "neo-tree" then
+    return M._get_neotree_selection()
+  else
+    return nil, "Not in a supported tree buffer (current filetype: " .. current_ft .. ")"
+  end
+end
+
+--- Get selected files from nvim-tree
+--- Supports both multi-selection (marks) and single file under cursor
+--- @return table files List of file paths
+--- @return string|nil error Error message if operation failed
+function M._get_nvim_tree_selection()
+  local success, nvim_tree_api = pcall(require, "nvim-tree.api")
+  if not success then
+    logger.warn("integrations", "nvim-tree API not available")
+    return {}, "nvim-tree not available"
+  end
+  
+  local files = {}
+  
+  -- Check for multi-selection first (marked files)
+  local marks = nvim_tree_api.marks.list()
+  if marks and #marks > 0 then
+    logger.debug("integrations", "Found " .. #marks .. " marked files in nvim-tree")
+    for _, mark in ipairs(marks) do
+      if mark.type == "file" and mark.absolute_path then
+        table.insert(files, mark.absolute_path)
+        logger.debug("integrations", "Added marked file: " .. mark.absolute_path)
+      end
+    end
+    if #files > 0 then
+      return files, nil
+    end
+  end
+  
+  -- Fall back to node under cursor
+  local node = nvim_tree_api.tree.get_node_under_cursor()
+  if node then
+    if node.type == "file" and node.absolute_path then
+      logger.debug("integrations", "Found file under cursor: " .. node.absolute_path)
+      return { node.absolute_path }, nil
+    elseif node.type == "directory" then
+      return {}, "Cannot add directory to Claude context. Please select a file."
+    end
+  end
+  
+  return {}, "No file found under cursor"
+end
+
+--- Get selected files from neo-tree
+--- Supports both multi-selection and single file under cursor
+--- @return table files List of file paths
+--- @return string|nil error Error message if operation failed
+function M._get_neotree_selection()
+  local success, manager = pcall(require, "neo-tree.sources.manager")
+  if not success then
+    logger.warn("integrations", "neo-tree manager not available")
+    return {}, "neo-tree not available"
+  end
+  
+  local state = manager.get_state("filesystem")
+  if not state then
+    logger.warn("integrations", "neo-tree filesystem state not available")
+    return {}, "neo-tree filesystem state not available"
+  end
+  
+  local files = {}
+  
+  -- Check for multi-selection first
+  if state.tree and state.tree.get_selection then
+    local selection = state.tree:get_selection()
+    if selection and #selection > 0 then
+      logger.debug("integrations", "Found " .. #selection .. " selected items in neo-tree")
+      for _, node in ipairs(selection) do
+        if node.type == "file" and node.path then
+          table.insert(files, node.path)
+          logger.debug("integrations", "Added selected file: " .. node.path)
+        end
+      end
+      if #files > 0 then
+        return files, nil
+      end
+    end
+  end
+  
+  -- Fall back to current node under cursor
+  if state.tree then
+    local node = state.tree:get_node()
+    if node then
+      if node.type == "file" and node.path then
+        logger.debug("integrations", "Found file under cursor: " .. node.path)
+        return { node.path }, nil
+      elseif node.type == "directory" then
+        return {}, "Cannot add directory to Claude context. Please select a file."
+      end
+    end
+  end
+  
+  return {}, "No file found under cursor"
+end
+
+return M