## Build wrapped Firefox with extensions and policies
The `wrapFirefox` function allows to pass policies, preferences and extension that are available to firefox. With the help of `fetchFirefoxAddon` this allows build a firefox version that already comes with addons pre-installed:
If `nixExtensions != null` then all manually installed addons will be uninstalled from your browser profile.
To view available enterprise policies visit [enterprise policies](https://github.com/mozilla/policy-templates#enterprisepoliciesenabled)
or type into the Firefox url bar: `about:policies#documentation`.
Nix installed addons do not have a valid signature, which is why signature verification is disabled. This does not compromise security because downloaded addons are checksumed and manual addons can't be installed.
If addons do not appear installed although they have been defined in your nix configuration file reset the local addon state of your Firefox profile by clicking `help -> restart with addons disabled -> restart -> refresh firefox`. This can happen if you switch from manual addon mode to nix addon mode and then back to manual mode and then again to nix addon mode.