tsgo-bridge

tsgo-bridge connects Claude Code and Codex to the TypeScript 7 native language server (tsgo). It works on Windows, macOS, and Linux.

繁體中文說明

What it does

tsgo-bridge gives the agent TypeScript and JavaScript code intelligence from tsgo:

• Type errors after each edit.

• Go to definition.

• Find references.

• Hover information and document symbols.

In Claude Code, the agent gets this information through the LSP plugin. In Codex, the agent gets it through MCP tools (ts_diagnostics, ts_definition, ts_references, ts_hover, ts_symbols).

Related MCP server: tsserver-mcp-server

Benefits

• The agent sees its own type errors. After an edit, the agent gets the errors in the next step. It can correct them before it continues.

• The agent finds code by meaning. It can use definitions and references instead of a text search. A text search can find words that have the same name but a different meaning.

• Less memory. tsgo uses approximately half the memory of tsserver. Each session starts its own server, so the saving increases with the number of sessions.

• Idle stop. tsgo-bridge stops tsgo after 10 idle minutes. The next request starts it again in approximately 1 second.

• One install for two clients. One setup command installs the Claude Code plugin and the Codex MCP server. It works on Windows, macOS, and Linux.

• No change to your projects. tsgo-bridge uses a private copy of TypeScript 7 for the agent only. Your project builds continue to use the TypeScript version of the project.

• Reversible. uninstall removes tsgo-bridge and enables the plugins that setup disabled.

The numbers come from tests on one Windows computer. Your results can be different.

Why this exists

tsgo-bridge is a temporary bridge. It exists because tsgo and the agent clients do not work together directly at this time.

1. tsgo does not push diagnostics. The TypeScript 7 language server sends per-file diagnostics only when the client asks for them (pull, textDocument/diagnostic). It does not send textDocument/publishDiagnostics (push).

2. Claude Code accepts only pushed diagnostics. Claude Code does not ask the server for diagnostics. If you connect tsgo directly to Claude Code, Claude Code shows no type errors after an edit.

3. Codex has no LSP client. Codex cannot use any language server directly. It can use MCP servers.

These issues track the problem. Status on 2026-11-01:

tsgo-bridge also contains two workarounds for tsgo:

• It does not send a second initialized notification to tsgo. tsgo stops with an error if it gets two.

• It does not tell tsgo that the client watches files. tsgo then watches the files itself.

When to remove it

You can remove the Claude Code part when one of these conditions is true:

• tsgo sends pushed diagnostics.

• Claude Code asks the server for diagnostics (pull).

Before you remove it, set TSGO_PULL_TO_PUSH=0 and check that Claude Code still shows type errors. tsgo-bridge then only passes messages between Claude Code and tsgo, and stops tsgo when it is idle.

You can remove the Codex part when Codex has an LSP client.

How it works

• Claude Code: The plugin tsgo-lsp adds an LSP server. TypeScript 7 sends diagnostics only when the client asks for them (pull). Claude Code accepts only diagnostics that the server sends (push). tsgo-bridge asks tsgo for the diagnostics and sends them to Claude Code.

• Codex: Codex has no LSP client. tsgo-bridge adds the MCP server tsgo and the skill tsgo-typecheck. The skill tells Codex to check types after it edits a TypeScript file.

Requirements

• Node.js 20 or later, with npm.

• git.

• Claude Code CLI, Codex CLI, or both.

Install

1. Show the changes that setup will make. This command does not change your settings.

   npx -y github:treuwok/tsgo-bridge setup --dry-run

2. Install.

   npx -y github:treuwok/tsgo-bridge setup

3. Check the installation.

   npx -y github:treuwok/tsgo-bridge doctor

4. Start a new Claude Code or Codex session.

Setup disables other plugins that also register an LSP server for .ts or .js files. Claude Code gives each file extension to the first plugin that registers it. If a different plugin keeps .ts, Claude Code does not use tsgo-lsp.

If a conflicting plugin also serves other languages (for example, Python), setup does not disable it. Setup shows CONFLICT and the languages that you will lose. To disable the plugin, run setup again with --disable-conflicting.

Options

Uninstall

npx -y github:treuwok/tsgo-bridge uninstall

Uninstall removes the plugin, the MCP server, and the skill. It also enables the plugins that setup disabled.

Limitations

• TypeScript 7 is stricter than TypeScript 5 and 6. It can show errors that your project build does not show.

• tsgo-bridge does not load TypeScript plugins from tsconfig.json (for example, the Next.js plugin).

• tsgo-bridge does not support Vue, Svelte, or Astro templates.

• After an idle stop, the first request takes approximately 1 second longer.

Development

npm install
npm test
node bin/tsgo-bridge.mjs doctor

For the design and the test results, see docs/.