Houdini is a full-stack GraphQL client framework with a compile-time-first approach, targeting React and Svelte applications. It consists of a Go-based compiler pipeline that extracts GraphQL documents from source files, generates optimized runtime artifacts (TypeScript), and manages caching, pagination, subscriptions, and optimistic updates. The runtime includes a normalized cache with fine-grained reactivity, client-side pagination (cursor and offset), progressive form handling with CSRF protection, OAuth integration, and a file-based routing system. The framework also provides a Vite plugin for HMR, a language server (LSP) with GraphQL completions and diagnostics, and production adapters for Node.js, Cloudflare, and static hosting. The architecture is hybrid: the core compiler is written in Go using SQLite for metadata storage, while the client runtime and framework integrations are TypeScript, with a plugin system supporting both Go and JavaScript extensions. The codebase is highly modular, with extensive unit and end-to-end test coverage across both SvelteKit and React.