LSP Setup for GitHub Copilot CLI

UTILITY SKILL — installs and configures Language Server Protocol servers for Copilot CLI. USE FOR: "setup LSP", "install language server", "configure LSP for Java", "add TypeScript LSP", "enable code intelligence", "I need go-to-definition", "find references not working", "need better code understanding" DO NOT USE FOR: general coding tasks, IDE/editor LSP configuration, non-Copilot-CLI setups

Workflow

1. Ask the language — use ask_user to ask which programming language(s) the user wants LSP support for
2. Detect the OS — run uname -s (or check for Windows via $env:OS / %OS%) to determine macOS, Linux, or Windows
3. Look up the LSP server — read references/lsp-servers.md for known servers, install commands, and config snippets
4. Ask scope — use ask_user to ask whether the config should be user-level (~/.copilot/lsp-config.json) or repo-level (lsp.json at the repo root or .github/lsp.json)
5. Install the server — run the appropriate install command for the detected OS
6. Write the config — merge the new server entry into the chosen config file (~/.copilot/lsp-config.json for user-level; lsp.json or .github/lsp.json for repo-level). If a repo-level config already exists, keep using that location; otherwise ask the user which repo-level location they prefer. Create the file if missing and preserve existing entries.
7. Verify — confirm the LSP binary is on $PATH and the config file is valid JSON

Configuration Format

Copilot CLI reads LSP configuration from user-level or repo-level locations, and repo-level config takes precedence over user-level config: