Go primitives for practical LSP servers

go-lsp handles JSON-RPC framing, method dispatch, LSP protocol types, document state, testing, and debugging tools so your server code can focus on language behavior.

Start Building API Reference

Install

go get github.com/owenrumney/go-lsp

Quick Server

type Handler struct{}

func (h *Handler) Initialize(context.Context, *lsp.InitializeParams) (*lsp.InitializeResult, error) {
    return &lsp.InitializeResult{
        ServerInfo: &lsp.ServerInfo{Name: "mylang", Version: "0.1.0"},
    }, nil
}

func (h *Handler) Shutdown(context.Context) error { return nil }

func main() {
    srv := server.NewServer(&Handler{})
    log.Fatal(srv.Run(context.Background(), server.RunStdio()))
}

What You Get

Interface-based handlers

Implement only the LSP features you need. The server registers methods and advertises capabilities automatically.

Document storage

document.Store applies full or incremental sync and handles UTF-16 LSP positions.

Test harness

servertest simulates an LSP client over in-memory pipes for focused handler tests.

Debug traces

The debug UI captures live traffic, logs, timelines, and exportable traces for bug reports.