code-intelligence-lsp-setup

When to invoke

• Adding LSP support to a plugin for a new language
• The agent is missing go-to-definition / find-references / hover info
• An LSP server fails to start (binary missing from PATH, init options wrong)
• Migrating from inline LSP config to plugin-scoped .lsp.json

Shape of .lsp.json

Per vendor/anthropics/code.claude.com/docs/en/plugins-reference.md (LSP §), a plugin's .lsp.json lives at the plugin root next to .claude-plugin/plugin.json. It maps language IDs to LSP server specs:

{
  "servers": {
    "typescript": {
      "command": "typescript-language-server",
      "args": ["--stdio"],
      "rootMarkers": ["package.json", "tsconfig.json"],
      "fileTypes": ["typescript", "typescriptreact", "javascript"]
    },
    "python": {
      "command": "pyright-langserver",
      "args": ["--stdio"],
      "rootMarkers": ["pyproject.toml", "setup.py"],
      "fileTypes": ["python"]
    }
  }
}

Picking a server

The canonical list lives at https://github.com/microsoft/language-server-protocol/blob/main/_implementors/servers.md. Operator's prior probe surfaced these high-quality choices:

Language	Server	Install hint
TypeScript/JS	typescript-language-server	npm i -g typescript-language-server
Python	pyright-langserver	npm i -g pyright
Go	gopls	go install golang.org/x/tools/gopls@latest
Rust	rust-analyzer	rustup component
Bash	bash-language-server	npm i -g bash-language-server

Failure modes

• Binary not on PATH: the LSP silently doesn't start. Check which <command> before adding to .lsp.json.
• Wrong rootMarkers: the LSP starts but reports "no project" — confirm the marker file exists at the workspace root.
• fileTypes mismatch: editor language ID and the spec's fileTypes must match exactly. typescript ≠ tsx.

Citations

• vendor/anthropics/code.claude.com/docs/en/plugins-reference.md (LSP §)
• vendor/agentskills/agentskills.io/specification.md (SKILL shape)
• https://github.com/microsoft/language-server-protocol/blob/main/_implementors/servers.md