Migrate from v1 to v2

v2 moves the whole toolchain forward: the runtime now ships React 19 and builds with Vite 8 (Rolldown-powered). Slides you wrote for v1 need no changes — the migration is confined to package.json, your Node version, and your deploy config.

Requirements

Node.js 20.19+ (or 22.12+). Vite 8 no longer supports Node 18, so open-slide dev and open-slide build won't start on older runtimes.

Update your workspace

Point your dependencies at the new majors:

package.json

{
  "dependencies": {
    "@open-slide/core": "^2.0.0",
    "react": "^19.2.8",
    "react-dom": "^19.2.8"
  },
  "devDependencies": {
    "@types/react": "^19.2.18",
    "@types/react-dom": "^19.2.5"
  }
}

Then reinstall and pull the latest agent skills:

npm install
npm run sync:skills

What if I keep React 18 in package.json?

The app still runs. Core dedupes react and react-dom to its own React 19 copy at runtime, so a stale React 18 entry never loads a second copy (two copies would crash the production bundle with React error #525). Bump anyway: your editor otherwise typechecks slides against React 18 types while the runtime is React 19.

Remove the `vite` devDependency

v1 scaffolds carried "vite" in devDependencies purely so hosting providers would detect a Vite project. In v2 it has to go. Core depends on Vite 8, and a stale Vite 5 entry makes package managers that hoist without checking peer ranges (bun, yarn classic) place core's Vite plugins next to the wrong copy, so open-slide dev, open-slide build, and open-slide preview fail with:

Package subpath './internal' is not defined by "exports" in .../node_modules/vite/package.json

npm and pnpm happen to nest the plugins correctly, but don't rely on it. open-slide checks for a mismatched vite on startup and refuses to run until it is removed, pointing back to this page.

Remove vite from devDependencies, reinstall, and declare the build settings explicitly so your host still knows how to build the project:

vercel.json

{
  "buildCommand": "npm run build",
  "outputDirectory": "dist",
  "rewrites": [{ "source": "/(.*)", "destination": "/index.html" }]
}

netlify.toml

[build]
  command = "npm run build"
  publish = "dist"

[[redirects]]
  from = "/*"
  to = "/index.html"
  status = 200

Slide code

Slides are plain React components, so React 19's removals apply: defaultProps on function components, string refs, and propTypes are gone. Typical agent-authored slides use none of these — if yours do, the dev server's error overlay will point at the offending page.