Advanced Configuration

This guide covers all advanced configuration options available in LibreBooking. For basic setup, see Basic Configuration first.

All settings are configured in the <INSTALL_DIR>/config/config.php file, where <INSTALL_DIR> is the root directory of your LibreBooking installation. The configuration uses a mix of flat dot notation and nested arrays.

Environment Variable Override

LibreBooking supports overriding any configuration setting using environment variables. This provides flexibility for deployment scenarios and keeps sensitive data separate from configuration files.

Naming Convention

Environment variables follow the pattern: LB_ + config key with special characters converted:

  • Dots (.) and dashes (-) become underscores (_)

  • All letters converted to uppercase

Examples

# Configuration key → Environment variable
app.title → LB_APP_TITLE
database.hostspec → LB_DATABASE_HOSTSPEC
phpmailer.smtp.host → LB_PHPMAILER_SMTP_HOST
reservation.prevent.participation → LB_RESERVATION_PREVENT_PARTICIPATION
Using .env Files

Create a .env file in your application root directory:

LB_APP_TITLE='My Company Booking'
LB_DATABASE_HOSTSPEC='db.example.com'
LB_ADMIN_EMAIL='admin@mycompany.com'

LibreBooking will automatically load and use these values.

Docker Integration

Environment variables work seamlessly with Docker:

# docker-compose.yml
services:
  librebooking:
    environment:
      - LB_APP_TITLE=Company Booking System
      - LB_DATABASE_HOSTSPEC=mysql
      - LB_ADMIN_EMAIL=admin@company.com
Complete Example

See develop/app/.env.example for a comprehensive list of all available environment variables with their default values and descriptions.

Maintenance Mode

LibreBooking can be placed into maintenance mode by creating a file named maint.txt in the root directory of the installation.

When <INSTALL_DIR>/maint.txt exists, normal page rendering is replaced with a maintenance notice. This is useful during upgrades, database migrations, or other planned maintenance windows where users should not use the application.

Enable maintenance mode

touch maint.txt

Disable maintenance mode

rm maint.txt

The contents of maint.txt are not used. LibreBooking only checks whether the file exists. The maintenance notice text comes from the MaintenanceNotice language string and can be customized with config/lang-overrides.php.

Application Advanced Settings

app.debug

Enable or disable debug mode for the application.

'app.debug' => false,
admin.email.name

Display name used for outgoing admin emails.

'admin.email.name' => 'LB Administrator',

Frontend Advanced Settings

inactivity.timeout

Time in minutes before a user is logged out due to inactivity.

'inactivity.timeout' => 30,
use.local.js.libs

Prefer bundled or self-hosted frontend assets instead of CDN-hosted ones, including supported fonts and JavaScript libraries.

'use.local.js.libs' => true,
home.url

URL to redirect users after login.

'home.url' => '',
logout.url

URL to redirect users after logout.

'logout.url' => '',
css.extension.file

Path of a custom CSS file to extend the default styles. If the value does not contain a slash (/) anywhere in the name, it is treated as relative to the Web/css/ directory (for example, 'css.extension.file' => 'custom.css'). If the value contains a slash, it is treated as a path relative to the Web/ root (for example, 'css.extension.file' => 'css/custom.css').

'css.extension.file' => '',
name.format

Format for displaying user names.

'name.format' => '{first} {last}',

Language Selector

When logged in, users see a globe icon in the navigation bar that lets them switch the UI language. The dropdown lists all languages defined in lang/AvailableLanguages.php.

Limiting available languages

Use the enabled.languages setting in config/config.php to restrict which languages appear in the selector. Provide a comma-separated list of language codes. Languages appear in the selector in the order listed:

# Show only English, Spanish, and French
'enabled.languages' => 'en_us,es,fr_fr',

Leave the value empty (the default) to show all supported languages. Language codes must match those defined in lang/AvailableLanguages.php. Any unrecognized codes will be logged as errors and ignored.

Important

The default.language value in config/config.php must be included in the enabled.languages list. If it is not, the application will fall back to en_us and log an error.

Hiding the language selector entirely

If only one language remains in the list, the language selector is automatically hidden from the navigation bar.

Page Control

'pages' => [
    'configuration.enabled' => true,
],
pages.configuration.enabled

Enable or disable the configuration page in the admin panel.

default.page.size

Default number of items per page in listings. Use a positive integer; -1 is not supported for performance reasons.

'default.page.size' => 50,

Advanced Email Configuration

email.enforce.custom.template

Force the use of a custom email template for all emails.

'email' => [
    'enforce.custom.template' => false,
],

Advanced PHPMailer Settings

'phpmailer' => [
    'sendmail.path' => '/usr/sbin/sendmail',
    'smtp.debug' => false,
    'smtp.autotls' => true,
],
phpmailer.sendmail.path

Path to the sendmail binary.

phpmailer.smtp.debug

Enable SMTP debug output (true/false).

phpmailer.smtp.autotls

Set PHPMailer’s SMTPAutoTLS setting (true/false). Determines if an unencrypted SMTP connection should attempt to use STARTTLS.

Logging Configuration

'logging' => [
    'folder' => '/var/log/librebooking/log',
    'level' => 'none',
    'sql' => false,
],
logging.folder

Directory where log files are stored.

logging.level

Logging level: none, DEBUG, INFO, WARNING, ERROR.

logging.sql

Enable or disable logging of SQL queries.

File Upload Settings

'uploads' => [
    'image.upload.directory' => 'Web/uploads/images',
    'image.upload.url' => 'Web/uploads/attachments',
    'reservation.attachments.enabled' => false,
    'reservation.attachment.path' => 'Web/uploads/attachments',
    'reservation.attachment.extensions' => 'pdf,doc,docx,xls,xlsx,png,jpg,jpeg,gif',
],
uploads.image.upload.directory

Directory for uploaded images.

uploads.image.upload.url

URL path for uploaded images.

uploads.reservation.attachments.enabled

Allow users to attach files to reservations.

uploads.reservation.attachment.path

Directory for reservation attachments.

uploads.reservation.attachment.extensions

Comma-separated list of allowed file extensions for attachments.

Notification Settings

Configure email notifications for different events:

'reservation.notify' => [
    'application.admin.add' => false,
    'application.admin.update' => false,
    'application.admin.delete' => false,
    'application.admin.approval' => false,
    'group.admin.add' => false,
    'group.admin.update' => false,
    'group.admin.delete' => false,
    'group.admin.approval' => false,
    'resource.admin.add' => false,
    'resource.admin.update' => false,
    'resource.admin.delete' => false,
    'resource.admin.approval' => false,
],

Schedule Display Settings

'schedule' => [
    'auto.scroll.today' => true,
    'show.week.numbers' => false,
    'hide.blocked.periods' => false,
    'show.inaccessible.resources' => true,
    'reservation.label' => '{name}',
    'use.per.user.colors' => false,
    'update.highlight.minutes' => 0,
    'fast.reservation.load' => false,
    'load.mobile.views' => true,
],
schedule.auto.scroll.today

Automatically scroll to current date when loading schedules.

schedule.show.week.numbers

Display week numbers in calendar views.

schedule.hide.blocked.periods

Hide time periods that are blocked from booking.

schedule.show.inaccessible.resources

Show resources that users cannot book (grayed out).

schedule.reservation.label

Template for reservation labels. Available tokens: {name}, {title}, {description}, {email}, {phone}, {organization}, {position}, {startdate}, {enddate}, {resourcename}, {participants}, {invitees}, {reservationAttributes}, and custom attributes like {att1}.

schedule.use.per.user.colors

Use different colors for each user’s reservations.

schedule.update.highlight.minutes

Minutes to highlight recently updated reservations (0 = disabled).

schedule.fast.reservation.load

(EXPERIMENTAL): Use a faster client-side reservation rendering algorithm in the standard desktop schedule view. This can improve performance on busy schedules, but it may incorrectly render some layouts or slot configurations.

schedule.load.mobile.views

Use simplified views on mobile devices.

Reservation Behavior

'reservation' => [
    'prevent.participation' => false,
    'prevent.recurrence' => false,
    'allow.guest.participation' => false,
    'allow.wait.list' => false,
    'start.time.constraint' => 'future',
    'updates.require.approval' => false,
    'title.required' => false,
    'description.required' => false,
    'checkin.minutes.prior' => 5,
    'checkin.admin.only' => false,
    'checkout.admin.only' => false,
    'reminders.enabled' => false,
    'default.start.reminder' => '',
    'default.end.reminder' => '',
],
reservation.prevent.participation

Disable reservation participation/invitations and hide participant/invitee lists in the reservation UI.

reservation.prevent.recurrence

Disable recurring/repeating reservations.

reservation.allow.guest.participation

Allow non-registered users to be added as participants.

reservation.allow.wait.list

Enable waitlist when resources are fully booked.

reservation.start.time.constraint

Restrictions on when reservations can be made: ‘none’, ‘current’, ‘future’. Note: In the standard reservation create/update flow, application admins are always exempt from this constraint. Group admins are exempt when they administer the reservation owner (user), while resource and schedule admins are exempt only when they administer all resources in the reservation.

reservation.updates.require.approval

Require approval when editing existing approved reservations.

reservation.title.required

Force users to enter a title/subject for reservations.

reservation.description.required

Force users to enter a description for reservations.

reservation.checkin.minutes.prior

How many minutes before start time check-in is allowed.

reservation.checkin.admin.only

Restrict check-in to administrators only.

reservation.checkout.admin.only

Restrict check-out to administrators only.

reservation.reminders.enabled

Enable email reminders before reservations start/end.

reservation.default.start.reminder

Default reminder time before start (e.g., ‘15 minutes’, ‘1 hours’, ‘1 days’).

reservation.default.end.reminder

Default reminder time before end.

Reservation Label Templates

'reservation.labels' => [
    'ics.summary' => '{title}',
    'ics.my.summary' => '{title}',
    'rss.description' => '<div><span>Start</span> {startdate}</div><div><span>End</span> {enddate}</div><div><span>Organizer</span> {name}</div><div><span>Description</span> {description}</div>',
    'my.calendar' => '{resourcename} {title}',
    'resource.calendar' => '{name}',
    'reservation.popup' => '',
],

These templates control how reservations appear in different contexts using the same tokens as schedule.reservation.label.

Reports Settings

'reports' => [
    'allow.all.users' => false,
],
reports.allow.all.users

Allow all users to access reports (not just admins).

Advanced Registration Settings

'registration' => [
    'auto.subscribe.email' => false,
    'require.phone' => false,
    'require.position' => false,
    'require.organization' => false,
    'hide.phone' => false,
    'hide.position' => false,
    'hide.organization' => false,
],
registration.auto.subscribe.email

Automatically subscribe new users to email notifications.

registration.require.phone

Require phone number during registration.

registration.require.position

Require position during registration.

registration.require.organization

Require organization during registration.

registration.hide.phone

Hide phone field during registration.

registration.hide.position

Hide position field during registration.

registration.hide.organization

Hide organization field during registration.

Resource Settings

'resource' => [
    'contact.is.user' => false,
],
resource.contact.is.user

Indicates if the contact must be a registered user.

Tablet View Settings

'tablet.view' => [
    'allow.guest.reservations' => false,
    'auto.suggest.emails' => false,
],
tablet.view.allow.guest.reservations

Allow guests to make reservations from the tablet view.

tablet.view.auto.suggest.emails

Auto-suggest email addresses during reservation creation.

ICS Calendar Settings

'ics' => [
    'subscription.key' => '',
    'future.days' => 30,
    'past.days' => 0,
],
ics.subscription.key

Secret key for calendar feed URLs (prevents unauthorized access).

ics.future.days

Number of future days to include in calendar feeds.

ics.past.days

Number of past days to include in calendar feeds.

Data Cleanup Settings

'cleanup' => [
    'years.old.data' => 3,
    'delete.old.announcements' => false,
    'delete.old.blackouts' => false,
    'delete.old.reservations' => false,
],
cleanup.years.old.data

Age in years when data is considered “old” for cleanup.

cleanup.delete.old.announcements

Automatically delete old announcements.

cleanup.delete.old.blackouts

Automatically delete old blackout periods.

cleanup.delete.old.reservations

Automatically delete old reservation records.

Note: Cleanup requires setting up a cron job to run deleteolddata.php.

Advanced Privacy Settings

'privacy' => [
    'view.schedules' => true,
    'hide.user.details' => false,
    'hide.reservation.details' => false,
    'public.future.days' => 30,
],
privacy.view.schedules

Hide schedule and calendar from unauthenticated users.

privacy.hide.user.details

Hide user details from other users.

privacy.hide.reservation.details

Hide reservation details from other users.

privacy.public.future.days

Number of future days visible to the public.

Advanced Security Settings

'security' => [
    'headers' => false,
    'strict-transport' => 'max-age=31536000',
    'x-frame' => 'deny',
    'x-content-type' => 'nosniff',
    'content-security-policy' => '',
],
security.headers

Enable sending of security headers.

security.strict-transport

Enable HTTP Strict Transport Security (HSTS).

security.x-frame

X-Frame-Options header (prevents clickjacking).

security.x-content-type

X-Content-Type-Options header.

security.content-security-policy

Content Security Policy header.

reCAPTCHA Advanced Settings

'recaptcha' => [
    'request.method' => 'curl',
],
recaptcha.request.method

HTTP method to use for reCAPTCHA validation. Options: curl, post, socket.

Credits System

'credits' => [
    'enabled' => false,
    'allow.purchase' => false,
],
credits.enabled

Enable credit-based reservation system.

credits.allow.purchase

Allow users to purchase additional credits.

Analytics Integration

google.analytics.tracking.id

Google Analytics tracking ID.

'google.analytics.tracking.id' => '',

Third-Party Integrations

slack.token

Slack webhook token for notifications.

'slack.token' => '',

Authentication Providers

'authentication' => [
    'hide.login.prompt' => false,
    'captcha.on.login' => false,
    'required.email.domains' => '',
    'google.login.enabled' => false,
    'google.client.id' => '',
    'google.client.secret' => '',
    'google.redirect.uri' => '/Web/google-auth.php',
    'microsoft.login.enabled' => false,
    'microsoft.client.id' => '',
    'microsoft.tenant.id' => 'common',
    'microsoft.client.secret' => '',
    'microsoft.redirect.uri' => '/Web/microsoft-auth.php',
    'facebook.login.enabled' => false,
    'facebook.client.id' => '',
    'facebook.client.secret' => '',
    'facebook.redirect.uri' => '/Web/facebook-auth.php',
    'keycloak.login.enabled' => false,
    'keycloak.url' => '',
    'keycloak.realm' => '',
    'keycloak.client.id' => '',
    'keycloak.client.secret' => '',
    'keycloak.client.uri' => '/Web/keycloak-auth.php',
    'oauth2.login.enabled' => false,
    'oauth2.name' => '',
    'oauth2.url.authorize' => '',
    'oauth2.url.token' => '',
    'oauth2.url.userinfo' => '',
    'oauth2.client.id' => '',
    'oauth2.client.secret' => '',
    'oauth2.client.uri' => '/Web/oauth2-auth.php',
],
authentication.hide.login.prompt

Hide the standard login form when external authentication is used.

authentication.captcha.on.login

Enable CAPTCHA on login forms.

authentication.required.email.domains

Comma-separated list of required email domains for login.

authentication.google.login.enabled

Allow users to log in with Google.

authentication.google.client.id

Client ID for Google authentication.

authentication.google.client.secret

Client secret for Google authentication.

authentication.google.redirect.uri

Redirect URI for Google authentication.

authentication.microsoft.login.enabled

Allow users to log in with Microsoft.

authentication.microsoft.client.id

Client ID for Microsoft authentication.

authentication.microsoft.tenant.id

Tenant ID for Microsoft authentication.

authentication.microsoft.client.secret

Client secret for Microsoft authentication.

authentication.microsoft.redirect.uri

Redirect URI for Microsoft authentication.

authentication.facebook.login.enabled

Allow users to log in with Facebook.

authentication.facebook.client.id

Client ID for Facebook authentication.

authentication.facebook.client.secret

Client secret for Facebook authentication.

authentication.facebook.redirect.uri

Redirect URI for Facebook authentication.

authentication.keycloak.login.enabled

Allow users to log in with Keycloak.

authentication.keycloak.url

Base URL for Keycloak server.

authentication.keycloak.realm

Keycloak realm name.

authentication.keycloak.client.id

Client ID for Keycloak authentication.

authentication.keycloak.client.secret

Client secret for Keycloak authentication.

authentication.keycloak.client.uri

Redirect URI for Keycloak authentication.

authentication.oauth2.login.enabled

Allow users to log in with OAuth2.

authentication.oauth2.name

Display name for OAuth2 login.

authentication.oauth2.url.authorize

Authorization URL for OAuth2 login.

authentication.oauth2.url.token

Token URL for OAuth2 login.

authentication.oauth2.url.userinfo

Userinfo URL for OAuth2 login.

authentication.oauth2.client.id

Client ID for OAuth2 login.

authentication.oauth2.client.secret

Client secret for OAuth2 login.

authentication.oauth2.client.uri

Redirect URI for OAuth2 login.

For OAuth2 and SAML setup details, see Oauth2 Configuration and SAML (Security Assertion Markup Language) Configuration.

Plugin System

'plugins' => [
    'authentication' => '',
    'authorization' => '',
    'export' => '',
    'permission' => '',
    'postregistration' => '',
    'prereservation' => '',
    'postreservation' => '',
    'styling' => '',
],

Available authentication plugins: ActiveDirectory, Apache, CAS, Drupal, Krb5, Ldap, Mellon, Moodle, MoodleAdv, Saml, Shibboleth, WordPress.

For authentication plugin configuration, see:

API Configuration

'api' => [
    'enabled' => false,
    'registration.allow.self' => false,
    'authentication.group' => '',
    'accessories.ro.group' => '',
    'accounts.ro.group' => '',
    'accounts.rw.group' => '',
    'attributes.ro.group' => '',
    'groups.ro.group' => '',
    'reservations.ro.group' => '',
    'reservations.rw.group' => '',
    'resources.ro.group' => '',
    'schedules.ro.group' => '',
    'users.ro.group' => '',
],
api.enabled

Enable the REST API.

api.registration.allow.self

Allow user registration via API.

api.authentication.group

Group required for API authentication (admins exempt).

api.*.ro.group

Groups with read-only access to specific API endpoints.

api.*.rw.group

Groups with read-write access to specific API endpoints.

Performance Tuning

For high-traffic installations:

  • Set cache.templates to true

  • Use use.local.js.libs = true to avoid third-party asset requests, or false to keep CDN-hosted assets.

  • Enable schedule.fast.reservation.load for busy schedules

  • Configure proper logging levels (avoid DEBUG in production)

  • Consider database optimization and caching

Troubleshooting

Performance Issues

  • Enable template caching

  • Check database query performance

  • Review logging levels

Email Problems

  • Test SMTP settings with external client

  • Check firewall rules

  • Verify DNS configuration

Authentication Issues

  • Check plugin configuration

  • Review server logs

  • Verify SSL certificates for external providers