# Customer Site Shell Hooks
https://dev.wisecp.com/es/client-site-shell-hooks
The sixteen placement points shared by every page: the head, the body, menus and the footer.
## Overview
The placement points present on every page of the site live here: the head section, the body, the menus, the footer and the system pages.
What they share is **scale**: what you place here runs on the home page, at the payment step and on an error page alike. Weigh the cost at that scale.
## Reference
### Adding a style to the site
uiclient.head.css
`website/inc` no parameters
Appears in the head section of the site, on **every page**. Link a stylesheet of your own here.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.head.css', 10, function () {
return 'Acme
';
});
```
### Adding a script to the site
uiclient.head.js
`website/inc` no parameters
The place to add a script on every page. It is the first thing a visitor meets: a heavy file delays the page opening.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.head.js', 10, function () {
return 'Acme
';
});
```
### The start of the body
uiclient.body.begin
`website/inc` no parameters
Appears at the very start of the page body. It suits an announcement banner across the site.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.body.begin', 10, function () {
return 'Acme
';
});
```
### The end of the body
uiclient.body.end
`website/inc` no parameters
Appears at the very end of the page body. The right place for modals and tracking scripts.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.body.end', 10, function () {
return 'Acme
';
});
```
### The end of the top bar
uiclient.topbar.end
`website/inc` no parameters
Appears at the end of the top bar.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.topbar.end', 10, function () {
return 'Acme
';
});
```
### The header action area
uiclient.header.actions
`website/inc` no parameters
Appears in the action area of the site header.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.header.actions', 10, function () {
return 'Acme
';
});
```
### The main menu items
uiclient.nav.items
`website/inc` no parameters
Appears among the items of the main menu. Use the same item markup so the menu structure holds.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.nav.items', 10, function () {
return 'Acme
';
});
```
### The sub-menu items
uiclient.subnav.items
`website/inc` no parameters
Appears among the items of the sub-menu.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.subnav.items', 10, function () {
return 'Acme
';
});
```
### The user menu items
uiclient.user_menu.items
`website/inc` no parameters
Appears in the menu of a signed-in user.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.user_menu.items', 10, function () {
return 'Acme
';
});
```
### The drawer items
uiclient.drawer.items
`website/inc` no parameters
Appears among the items of the mobile drawer. It is **separate from the main menu**: add to both if you want it in both places.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.drawer.items', 10, function () {
return 'Acme
';
});
```
### Above the footer
uiclient.footer.before
`website/inc` no parameters
Appears immediately above the footer.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.footer.before', 10, function () {
return 'Acme
';
});
```
### The footer columns
uiclient.footer.columns
`website/inc` no parameters
Appears among the footer columns.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.footer.columns', 10, function () {
return 'Acme
';
});
```
### The bottom of the footer
uiclient.footer.bottom
`website/inc` no parameters
Appears at the very bottom of the footer.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.footer.bottom', 10, function () {
return 'Acme
';
});
```
### Above the call-to-action band
uiclient.cta_band.before
`website/inc` no parameters
Appears above the call-to-action band at the foot of the page.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.cta_band.before', 10, function () {
return 'Acme
';
});
```
### The maintenance page body
uiclient.maintenance.body
`website/inc` no parameters
Appears in the body of the maintenance page. It runs **while the site is closed**: a listener reaching the database or an outside service here can take down the page at an already bad moment.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.maintenance.body', 10, function () {
return 'Acme
';
});
```
### The system page head
uiclient.system_page.head
`website/inc` no parameters
Appears in the head of the error and blocked pages. Those pages are shown **even when the core has failed**: give simple output with no dependencies.
Parameters 0
—It takes no parameters.
Return 1
string|nullThe **HTML you return appears**. With several listeners the outputs are appended one after another in priority order. Empty text, `null` and `false` are skipped, so return `null` when you have nothing to add. The output enters the page unescaped — clean anything coming from outside yourself.
Listener PHP
```php
Hook::add('ui:client.system_page.head', 10, function () {
return 'Acme
';
});
```
## Pitfalls
> **Shell points run at the payment step too**
>
> The head and body points run on **every page** of the site, the basket and the payment step included. A slow script there delays not one page but the purchase path itself.
> **Build no dependencies on the maintenance and error pages**
>
> The maintenance and system page points run at the moment the site is **already in trouble**. A listener reaching for the database or an outside service there takes down the last page the user would have seen. Give simple output with no dependencies.
## Related Articles
- [Customer Site Hooks](https://dev.wisecp.com/en/hooks-on-the-customer-site)
- [Customer Panel Data Hooks](https://dev.wisecp.com/en/client-panel-data-hooks)
- [Site Content Hooks](https://dev.wisecp.com/en/client-content-hooks)