# Install
Two paths, pick the one that matches how your site is built.
## Path 1: CDN snippet
Paste these tags into your ``:
```html
```
What this does:
1. The first tag starts fetching the SDK bundle in parallel with HTML
parsing (`async`). It does not block the browser.
2. The inline `
```
The hash for each release is in the release notes. The CDN also returns
it on every response as an `X-Content-Integrity` header, so you can
verify or fetch it programmatically.
## Path 2: npm install (bundler-based apps)
For React, Vue, Svelte, Next.js, Nuxt, and similar bundler-based
projects, install from npm and import the SDK like any other module.
```bash
bun add @revu-ai/core
# or: npm install @revu-ai/core
```
```js
import revu from "@revu-ai/core";
revu.init({ apiKey: "revu_pk_..." });
```
The npm distribution is ESM-only. Modern bundlers (Vite, Rollup,
esbuild, webpack 5+) tree-shake against `"sideEffects": false` so a
customer who imports only `revu.init` and `revu.capture` does not pay
for the modules they do not reach.
The CDN bundle and the npm bundle ship the same source, the same public
API, and the same wire shape. Pick whichever fits your build.
## What the bundle does not do
By design, the install path does not:
- Set any cookies on the CDN domain. The bundle is served cookieless.
- Block first paint. The bundle loads asynchronously.
- Require a build step or polyfills. The bundle targets ES2020 (Chrome
85+, Safari 13.1+, Firefox 79+, Edge 85+), which covers ~97% of
browsers globally without transpilation overhead.
- Force a specific module loader. Modern bundler, legacy `