LSP Auto-Activation

Pando automatically detects the programming language of files you open and starts the appropriate Language Server Protocol (LSP) server — providing real-time diagnostics, code completion support, and intelligent analysis without manual configuration.

How It Works

When you open a file in the TUI editor, the file tree, or when the agent reads/writes a file, Pando:

1. Detects the file extension (.go, .ts, .py, etc.)
2. Looks up the matching LSP server from its built-in catalog of 22 presets
3. Checks if the server binary is installed on your system
4. Starts the server automatically if available

If the binary isn’t installed, Pando marks it as unavailable and doesn’t retry — no error spam.

Built-in LSP Presets

Pando includes presets for these languages out of the box:

Configuration

Auto-Activation (Default)

By default, LSP auto-activation is enabled. Servers start on-demand when you open a matching file.

Web UI: Settings > LSP — shows per-server status (installed/not installed), autostart toggle, and auto-activation info.

TUI: Settings > LSP — same fields with keyboard navigation.

Configuration file:

# Global: enable/disable on-demand activation (default: true)
LSPAutoActivate = true

# Per-server configuration
[LSP.gopls]
# Start eagerly at boot (default: false)
Autostart = false

# Never start this server
Disabled = false

[LSP.pyright]
Autostart = true  # start pyright at boot

Autostart vs On-Demand

Workspace Watching

When LSP auto-activation is enabled, Pando watches your workspace for file changes. Opening or creating files with known extensions triggers automatic server startup — no manual intervention needed.

The watcher skips common non-source directories: .git, node_modules, vendor, dist, build, target, out.

Diagnostics

Once an LSP server is running, Pando shows real-time diagnostics:

• In the TUI status bar: Error and warning counts
• In the editor: Inline diagnostics as you navigate files
• Via the agent: The diagnostics tool can fetch issues for any file

Agent Integration

When the agent reads, writes, or edits a file, Pando ensures the matching LSP server is running. This means:

• Diagnostics are available immediately after file changes
• The agent can check for type errors and lint issues
• Code completion data is fresh and accurate

Presets vs Custom Servers

You can extend or override the built-in presets:

# Override a preset
[LSP.gopls]
Command = ["gopls", "-remote=auto"]
Autostart = true

# Add a custom server
[LSP.my-custom-lsp]
Command = ["my-lsp", "--stdio"]
Extensions = [".mylang"]

User-configured settings always take precedence over presets.

Troubleshooting

Server not starting

1. Check if the binary is on your PATH: which <binary-name>
2. Check Settings > LSP to see the server status
3. If marked “not installed”, install the language server for your system

Diagnostics not appearing

1. Ensure the LSP server is running (check Settings > LSP)
2. Verify the file extension matches the server’s configured extensions
3. Some servers need a project file (e.g., go.mod for gopls)

Server starts but crashes

Pando marks crashed servers and won’t restart them in the same session. Restart Pando to retry.