LSP/MCP server for synchronizing editor state between Crush (Charm's AI coding agent) and Neovim.

When Crush edits files, this server enables:

• Live buffer updates: Crush edits appear instantly in Neovim with flash highlights
• Cursor/selection tracking: AI tools can see your current position and selected text
• Auto-focus: Edited files open automatically in Neovim
• MCP integration: Provides editor_context and show_locations tools for AI assistants

• Daemon architecture: single daemon per workspace, multiple clients
• Auto-detection of LSP vs MCP protocol
• Flash highlights on AI edits (like yank highlight)
• No-op edits for unopened files (triggers highlight without doubling content)
• Secure socket placement ($XDG_RUNTIME_DIR or $TMPDIR)
• Custom crush/* methods for real-time cursor/selection tracking

go install github.com/taigrr/neocrush/cmd/neocrush@latest

Install neocrush.nvim for full integration:

-- lazy.nvim
{
  'taigrr/neocrush.nvim',
  event = 'VeryLazy',
  opts = {},
}

The plugin provides:

• Auto-start LSP on buffer enter
• Flash highlights on workspace/applyEdit
• Cursor position sync (crush/cursorMoved)
• Selection sync (crush/selectionChanged)
• Crush terminal management (:CrushToggle, <leader>cc)

Add neocrush to your ~/.config/crush/crush.json:

{
  "lsp": {
    "*": {
      "command": "neocrush"
    }
  },
  "mcp": {
    "neocrush": {
      "command": "neocrush",
      "type": "stdio"
    }
  },
  "permissions": {
    "allowed_tools": [
      "mcp_neocrush_editor_context",
      "mcp_neocrush_show_locations"
    ]
  }
}

• LSP integration: Crush edits sync to Neovim buffers in real-time
• MCP editor_context tool: AI can query current file, cursor position, surrounding code, and selection
• MCP show_locations tool: AI can present analyzed code locations with explanations in a Telescope picker

┌─────────────────────────────────────────────────────────────┐
│                    neocrush daemon                         │
│  ┌───────────────────────────────────────────────────────┐  │
│  │  Clients:                                             │  │
│  │  ├─ neovim: LSP over Unix socket                      │  │
│  │  ├─ crush:  LSP over Unix socket                      │  │
│  │  └─ mcp:    MCP over Unix socket                      │  │
│  │                                                       │  │
│  │  State:                                               │  │
│  │  ├─ documentState: map[uri]string (content cache)     │  │
│  │  ├─ neovimOpenDocs: map[uri]bool (open files)         │  │
│  │  ├─ cursorURI/Line/Column (last known position)       │  │
│  │  └─ selectionText (last visual selection)             │  │
│  └───────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────┘
         ▲                    ▲                    ▲
         │                    │                    │
   ┌─────┴─────┐        ┌─────┴─────┐        ┌─────┴─────┐
   │  Neovim   │        │   Crush   │        │ MCP Client│
   │  (LSP)    │        │   (LSP)   │        │ (AI tool) │
   └───────────┘        └───────────┘        └───────────┘

1. First client connects: Daemon starts, listens on Unix socket
2. Neovim attaches: Sends initialize, daemon tracks open files via didOpen/didClose
3. Crush edits a file:
   • If file is open in Neovim: send real diff via workspace/applyEdit
   • If file is not open: send no-op edit (triggers open + highlight without doubling)
4. MCP client calls editor_context: Returns cursor position + surrounding code
5. All clients disconnect: Daemon shuts down

# Build
go build ./cmd/neocrush

# Test
go test ./...

# Run with logging
neocrush --log /tmp/neocrush.log