Language Server

ttscserver is the LSP host. Install it through the VSCode extension (not yet on Marketplace — build packages/vscode-ttsc and code --install-extension the .vsix; Marketplace tracked for v1) and your editor sees lint diagnostics, plugin code actions, and plugin-defined commands as you type — same things ttsc would surface at build time, but live.


npx ttscserver --stdio   # plain LSP server over stdio

What you actually do

Almost always: nothing. You install the VSCode extension; it starts ttscserver from your project’s local node_modules. Diagnostics appear, code actions appear, commands appear.

If something doesn’t work, the recovery is in Troubleshooting.

What it adds beyond `tsgo`’s LSP

TypeScript-Go ships its own Language Server — type errors, hovers, completions, the usual. ttscserver wraps that server and splices in three things your ttsc plugins produce:

Event	What `ttscserver` adds
`textDocument/publishDiagnostics`	Lint findings for the same file are appended to the diagnostics array, so they show in the same gutter / underline UI.
`textDocument/codeAction`	Plugin-owned quick-fixes (e.g. `@ttsc/lint` autofixes) appear in the lightbulb menu alongside built-in TS code actions.
`workspace/executeCommand`	Plugin-defined commands (anything a plugin registers) are routed back to the plugin for the actual workspace edit.

All other traffic flows through to tsgo’s LSP unmodified.

CLI flags


ttscserver [--stdio] [--cwd <dir>] [--progress-delay <duration>]

Flag	Effect
`--stdio`	Use stdin/stdout for JSON-RPC. Required — `ttscserver` does not support other transports yet.
`--cwd <dir>`	Project root. Default: process working directory.
`--progress-delay <duration>`	How long to wait before emitting `$/progress` notifications for long compiles. Default `250ms`.

Talking to it from other editors

The wire protocol is plain LSP. Neovim, JetBrains’ LSP4IJ, Emacs lsp-mode, Helix, and any other LSP client can spawn ttscserver --stdio and get the same behavior the VSCode extension does.

Editor-specific niceties — output channel wiring, command-palette entries — need per-editor work. The VSCode extension is the only first-party client today. Contributions for other editors are welcome.

Trace the server

If diagnostics aren’t appearing or you want to see the raw JSON-RPC, add to .vscode/settings.json:


{
  "ttsc.trace.server": "verbose"
}

Then open View → Output and select ttsc from the dropdown.