@justbe/webview

A light, cross-platform library for building web-based desktop apps with Deno.

Note

This is alpha level software that's rapidly changing. Things might break. Please let me know if you notice anything missing or not working.

Example

import { createWebView } from "jsr:@justbe/webview";

using webview = await createWebView({
  title: "Example",
  html: "<h1>Hello, World!</h1>",
  devtools: true
});

webview.on("started", async () => {
  await webview.openDevTools();
  await webview.eval("console.log('This is printed from eval!')");
});

await webview.waitUntilClosed();

You can run this yourself with

deno run https://raw.githubusercontent.com/zephraph/webview/refs/heads/main/examples/simple.ts

Checkout the examples directory for more.

Permissions

When executing this package, it checks to see if you have the required binary for interfacing with the OS's webview. If it doesn't exist, it downloads it to a cache directory and executes it. This yields a few different permission code paths to be aware of.

Binary not in cache

This will be true of a first run of the package. These are the following permission requests you can expect to see:

• Read HOME env -- Used to locate the cache directory
• Read /deno-webview/deno-webview- -- Tries to read the binary from cache
• net to github.com:443 -- Connects to GitHub releases to try to download the binary (will be redirected)
• net to objects.githubusercontent.com:443 -- GitHub's CDN for the actual download
• Read /deno-webview/ -- Reads the cache directory
• Write /deno-webview/deno-webview- -- Writes the binary
• Run /deno-webview/deno-webview- -- Runs the binary

Binary cached

On subsequent runs you can expect fewer permission requests:

• Read HOME env -- Use to locate the cache directory
• Read /deno-webview/deno-webview-
• Run /deno-webview/deno-webview-

Allowed WEBVIEW_BIN

WEBVIEW_BIN is a special environment variable that, if present and allowed, will short circuit the binary resolution process in favor of the path specified. In this case there will be only one permission:

• Run <WEBVIEW_BIN>

Note that this environment variable will never be explicitly requested. If the script detects it's not allowed to read this env var it just skips this code path altogether.