Native manifests are specially formatted JSON files that are provisioned on the user's computer by some means outside the extension installation process. For example, a native manifest might be provisioned by a device administrator or by a native application installer.
There are three different types of native manifest:
Native messaging manifests | Enable a feature called native messaging, in which an extension can communicate with a native app installed on the device. |
Managed storage manifests | Define read-only data that an extension can access using the storage.managed API. |
PKCS #11 manifests | Enable an extension to use the pkcs11 API to enumerate PKCS #11 security modules and install them in Firefox. |
For all native manifests, you need to arrange things so the browser can find the manifest. The section on manifest location describes these rules.