The Blog

Introducing Wisp

Meet Wisp, a fast, fun web framework for Rust with file routes, templates compiled to Rust, form actions and one binary. Learn what it is and why we built it.

October 4, 2026 · The Wisp Team · 3 min read

Today we are sharing Wisp, a fast, fun web framework for Rust. A folder is a URL, its +page.wisp is the page, and the whole app, styles and static files included, builds to one small binary.

In this post, we will go through what Wisp looks like, the four rules we build it by, and where to start.

What a Wisp App Looks Like

Here is a todo list that validates its input, keeps its rows across restarts and works without JavaScript. The model lives in src/db.rs:

#[model]
pub struct Todo {
    #[validate(len = 1..=100)]
    text: String,
}
pub static TODOS: Table<Todo> = Table::saved();

And the page is src/routes/+page.wisp:

---
#[action]
fn add(todo: Todo) {
    TODOS.add(todo);
}
#[action]
fn remove(id: u64) {
    TODOS.remove(id);
}
---

<title>Todos ({TODOS.len()})</title>
<form action="?/add" fields><button>Add</button></form>
{#each TODOS.all() as todo}
  <p>{todo.text} <button action="?/remove&id={todo.id}">Remove</button></p>
{/each}

The block at the top is Rust that runs on the server. The markup below it is HTML with a few template tags. The form writes its own inputs and errors, and a bad value is a 422 that shows each problem beside its input and keeps what was typed. There are no use lines, no router file and no handler wiring.

Four Rules, in Order

When two goals pull apart, Wisp has an order for choosing:

1. Fast. A route pays only for the features it uses. A change that touches the request path is checked by an instructions-per-request A/B before it lands, and a feature a route does not use must add none.
2. Cheap in tokens. AI writes most code now, and every token it reads and writes costs time and money. Wisp uses conventions over configuration, types the compiler infers, and forms that write their own inputs and errors.
3. Durable. Each fast path is proven when the server starts, falls back to the plain path if the proof fails, and nothing after startup panics.
4. Flexible. Last in the order, and never at the cost of the first three.

Speed is never traded away for convenience. How it is measured, and how to run the benchmark tools yourself, is on the Benchmarks page.

Why Tokens

Code written by a model is paid for by the token, so we count them. The same five features, a list page, a contact form, a JSON endpoint, a layout and a live search, written as a complete app in each stack:

A bigger app, with sign up and in, a posts table, uploads, live refresh and a component, is 995 tokens in Wisp, 3473 in SvelteKit and 3331 in Next.js. The numbers come from cargo run -p wisp-tokens, which counts every hand-written file and its path with a byte-pair style estimate. The Tokens page has the method and the apps, so you can check the count.

For agents, AGENTS.md is the whole reference in one file, and wisp mcp serves the docs over MCP.

One Binary, Any Host

Templates compile to plain Rust, and wisp build writes one binary. It runs on a VPS, in a container, as static HTML or on an edge host:

wisp build
wisp build --static
wisp build --docker
wisp build --target cloudflare

--target also takes deno, vercel, netlify, node, bun and lambda. See Deploying.

Reactivity in the Same File

Pages work without JavaScript, and behavior lives in the same file as the markup. A <script> with $state adds it, and a write redraws only what read the value:

---
let name: String = cx.query_or("name", "world".to_string());
---

<h1>Hello, {name}!</h1>

<button on:click="count++">Clicked {:count} times</button>

<script>
  let count = $state(0)
</script>

Turn JavaScript off and the server's HTML still works. See Browser code.

Get Started

You need Rust 1.88 or later:

cargo install --git https://wisp.ar0.eu wisp-cli
wisp new my-app
cd my-app
wisp dev

The Quick Start covers the concepts in one page, and the Tutorial builds a small app from an empty folder. The code is at wyziedevs/wisp, and issues and pull requests are welcome. See Community for where to ask.

Thank you for trying Wisp.