Preview development servers

Startpod routes a supported development server through a browser-controlled preview URL.

Mount before spawning

Give Startpod the element that should contain the preview, then start the server:

startpod.mountPreview(document.querySelector("#preview-host")!)
const server = await startpod.spawn("npm", ["run", "dev"])

Startpod creates the iframe, connects its request bridge, and renders the project when the development server is ready.

The managed preview also exposes navigation controls:

startpod.mountPreview(document.querySelector("#preview-host")!)
startpod.navigatePreview("/settings")
startpod.reloadPreview()

Call unmountPreview() before removing the host element.

Use requestPreview() for an HTTP client or test panel that needs to call the active server without iframe navigation:

const response = await startpod.requestPreview({
  method: "GET",
  url: "/api/health",
})

console.log(response.status)

Set maxResponseBytes or an AbortSignal when user-controlled endpoints may return large or slow responses.