Overview

Wisp is the framework for the AI age: ultra fast to run, cheap in AI tokens to write, durable, and flexible.

Area	What you get
Reactivity	`$state`, `$derived`, `$effect` in a plain `<script>`, no build step. Islands (`client:visible`, `client:idle`, `client:media`) load code when needed. Components ship no JavaScript by default. Hot reload keeps `$state`; markup edits show in under 100 ms.
AI and tokens	AGENTS.md and llms-full.txt hold the whole reference. `wisp mcp` serves the docs to coding agents. A whole app takes about half the tokens of SvelteKit or Next.js (Tokens).
Rendering	Server-side rendering with streamed responses and server-streamed `{#await}`. Prerendered pages in a server build, `wisp build --static` and `--spa`.
Data and forms	`#[action]` form handlers with validation, and uploads. `#[remote]` functions called from the browser. `#[derive(Rest)]` gives a JSON CRUD API; a store keeps rows in log files or any database.
Styling	Scoped CSS in a `<style>` block, Tailwind and Sass built in.
Tooling	`wisp lsp` with a VS Code extension, plus Zed, tree-sitter and Prettier. `wisp fmt`, `wisp check`, `wisp test`, `wisp test --browser`. Devtools on `Alt+Shift+W`.
Deploy	One binary, `--docker`, `--static`, or `--target cloudflare\|deno\|vercel\|netlify\|node\|bun\|lambda`. `wisp deploy init <host>` writes a GitHub Actions workflow or a Fly, Render or Railway config.

Speed

Zero cost on the request hot path is the first rule: see Benchmarks. Wisp has no unsafe code outside its Linux I/O drivers and the edge exports.

Docs

Design: the template language, routing, actions and the runtime.
Browser code: scripts, directives, islands, stores and the router.
APIs and platforms: JSON APIs, validation, auth, OpenAPI and testing.
Deploying covers every host. Testing and mixing with Rust code covers axum, hyper and Lambda.
examples: a demo app, a JSON API and Wisp inside axum.

Issues and pull requests are welcome; read the design rule at the top of AGENTS.md first. License: MIT.

Status

Every feature passes four gates: fast (no cost for apps that don't use it), cheap (one line, file or attribute), durable (checked at build time, no new runtime panics) and done (tests, an AGENTS.md entry, a docs section). The roadmap runs in five phases.

Phase 1, the compiler: scoped styles, source maps, TypeScript in scripts, accessibility warnings, public and private environment variables (env.PUBLIC_X), Content Security Policy.
Phase 2, developer experience: editor support (wisp lsp), formatter (wisp fmt), hot reload that keeps state, devtools, browser E2E tests (wisp test --browser).
Phase 3, rendering and routing: SPA mode (const SSR: bool = false;), code loading on demand, server functions (#[remote]), shallow routing, snapshots, per-page prerendering (const PRERENDER: bool = true;), trailing slash.
Phase 4, content and assets: Markdown pages, image optimization, i18n, sitemap and robots.txt.
Phase 5, platform: service worker and PWA, web components ({@element "x-card"}), third-party UI (wisp ui add, framework islands), observability (WISP_LOG=json, /_wisp/metrics, OpenTelemetry).
Planned order: phase 1 first (scoped styles, source maps, TypeScript, accessibility warnings, env variables, CSP), then phase 2 (editor support and formatter first), then phase 3 (#[remote] and loading on demand first). Phases 4 and 5 are mostly independent.
Decisions: images use a pinned cwebp (sha256 checked, $WISP_CWEBP override; if unavailable the build warns and serves the original); Markdown uses pulldown-cmark at build time only; E2E tests are Rust only; i18n is supported while Wisp's own docs stay English.

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