tsserver-plugin-east

East diagnostics as a TypeScript language service plugin

tsserver-plugin-east rides inside the editor's existing TypeScript language service and surfaces @elaraai/east-diagnostics as native squiggles — no second type-checker, no ESLint setup required.

Features

• East idiom diagnostics - the full east-diagnostics rule set (prefer some()/none, no hand-rolled variants, redundant casts, unexecuted East expressions, prefer JSX tags, …) reported alongside TypeScript's own diagnostics.
• Readable East type errors - native assignability errors on East types are rewritten via east's structural type diff, so a mismatch deep inside a recursive type reads as one localized line instead of pages of restated generics.
• In-process - decorates the language service the editor already runs; no extra server or program build.
• Self-contained - a single CommonJS bundle; only typescript is expected from the host.

Usage

Add the plugin to compilerOptions in tsconfig.json and install it as a dev dependency:

{
  "compilerOptions": {
    "plugins": [{ "name": "@elaraai/tsserver-plugin-east" }]
  }
}

npm install --save-dev @elaraai/tsserver-plugin-east

In VS Code, tsconfig-configured plugins load when the workspace TypeScript version is selected ("TypeScript: Select TypeScript Version…"). The East UI Preview extension contributes the same plugin globally, which also covers VS Code's built-in TypeScript.

Projects scaffolded with npm create @elaraai/e3 / npm create @elaraai/east ship with the plugin preconfigured, alongside @elaraai/eslint-plugin-east for the same rules in CI.

Claude Code plugin

The East ecosystem also ships a Claude Code plugin — East language skills, example search, and preemptive diagnostics for East code — installed separately from the elaraai marketplace:

# Inside Claude Code
/plugin marketplace add elaraai/east-workspace
/plugin install east@elaraai

# From a terminal
claude plugin marketplace add elaraai/east-workspace
claude plugin install east@elaraai

License

Dual-licensed:

• Open Source: AGPL-3.0 - Free for open source use
• Commercial: Available for proprietary use - contact [email protected]

Developed by Elara AI Pty Ltd