NodlumeNodlume
Manifest V3 generator

Manifest V3 sidePanel permission

The sidePanel permission enables chrome.sidePanel — opening the panel programmatically, setting a per-tab path, and making the toolbar icon open the panel instead of a popup. The panel surface itself is declared under the side_panel manifest key; this permission is for controlling it from code.

It is Chrome-only (Firefox has sidebar_action instead), which is why generated code guards it behind a feature check. No install warning is shown, and the Nodlume manifest generator implies it whenever the side-panel surface is selected.

Side panel at a glance

Manifest key
"permissions": ["sidePanel"]
What it enables
Open the side panel programmatically. Implied by the side-panel surface above.
Install warning
None — granted silently at install.
Cross-browser API
browser.sidePanel via webextension-polyfill

The manifest that declares it

Manifest with this permission

manifest.json
{
  "manifest_version": 3,
  "name": "my-extension",
  "version": "0.1.0",
  "action": {
    "default_popup": "src/popup.html"
  },
  "background": {
    "service_worker": "src/background.ts",
    "type": "module"
  },
  "permissions": [
    "sidePanel"
  ]
}

This manifest installs with no permission warning.

sidePanel, answered

The longer version is in the guide Manifest V3 permissions: a practical guide.

What does the sidePanel permission do in Manifest V3?
Open the side panel programmatically. Implied by the side-panel surface above. It is declared as the string "sidePanel" in the manifest's permissions array; the browser grants it at install time, and the extension's service worker, popup and other pages can then call the matching API.
Does sidePanel show an install warning?
No. sidePanel is granted silently — it appears in the manifest but adds nothing to the install prompt. Host permissions and warning-bearing permissions such as tabs or downloads are what change the prompt.
Can I request sidePanel at runtime instead?
Yes. Move it from permissions to optional_permissions and call browser.permissions.request({ permissions: ["sidePanel"] }) from a user gesture when the feature is first used. The manifest generator emits the install-time form; optional grants are an edit to that JSON.

Build the whole manifest

The Chrome extension manifest generator declares every permission with its install warning shown up front, adds the surfaces the browser opens, and validates content-script match patterns before they can reject the whole extension. In the Nodlume workspace the same selection becomes a complete Manifest V3 project with a service worker and a Vite build.

Open the generator

Other Manifest V3 permissions

We'd like to use Google cookies to understand how Nodlume is used and to measure our advertising. Nothing loads until you choose, and declining does not affect anything in the app.