TypeScript

TypeScript is optional for Sprig applications. JavaScript is the implementation language, while declaration files provide public API types and editor hints for the core, form, router, and animation package entries.

.sprig <script setup> blocks remain JavaScript-only. The repository checks source declarations with npm test/npm run typecheck and checks emitted bundle declarations during npm run build. See TypeScript Overview, Composition API-style TypeScript, and Options API TypeScript for Sprig-specific guidance (the latter is explicitly not supported as an API).