Docker Self-Hosting
Deploy Tymeslot with Docker Compose on any VPS or home server. Includes reverse proxy setup, file upload volumes, and WebSocket configuration for LiveView.
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Environment Variables Reference
Complete reference for all Tymeslot environment variables — required settings, defaults, and examples.
Luka Breitig
Software Engineer & AI Developer
⚙️ Core Application
SECRET_KEY_BASE
Required
64+ character secret used for session encryption and signing. By default it also
derives the key that encrypts integration credentials at rest — so unless you set
DATA_ENCRYPTION_KEY
(below), rotating this value would make stored credentials undecryptable. Generate
with the command shown in the example.
Default: none ·
Example: openssl rand -base64 64 | tr -d '\\n'
DATA_ENCRYPTION_KEY
Optional
Dedicated key for encrypting integration credentials at rest, independent of SECRET_KEY_BASE. Setting it lets you rotate
SECRET_KEY_BASE
without breaking stored credentials. Base64 that decodes to at least 32 bytes; must
stay stable once set. On Cloudron it is generated automatically. See the
Data-at-Rest Encryption
guide for migration steps.
Default: derived from SECRET_KEY_BASE ·
Example: openssl rand -base64 48 | tr -d '\\n'
PHX_HOST
Required
Your domain name without the protocol prefix.
Default: none ·
Example: tymeslot.yourdomain.com
PORT
Optional
HTTP port for the application server to listen on.
Default: 4000 ·
Example: 4000
DEPLOYMENT_TYPE
Optional
Deployment variant. Set to docker
or cloudron
to control deployment-specific behaviour.
Default: auto-detected ·
Example: docker
REGISTRATION_ENABLED
Optional
Set to false
to disable new user registration on this instance. Also runtime-toggleable from the
admin UI
without a restart; a UI override takes precedence over this env var.
Default: true ·
Example: false
PASSWORD_AUTH_ENABLED
Optional
Set to false
to disable email/password login entirely. The login form, sign-up page, and password reset flow are hidden; only OAuth login is available. Useful for SSO-only deployments where all users must authenticate through an identity provider. Also runtime-toggleable from the admin UI.
Default: true ·
Example: false
LISTEN_IP
Optional
IP address to bind the HTTP server. Default ::
enables IPv4+IPv6 dual-stack.
Default: :: ·
Example: 0.0.0.0
URL_SCHEME
Optional
Request scheme used in generated URLs. Set to https
for production.
Default: https ·
Example: https
WS_ALLOWED_ORIGINS
Optional
Comma-separated list of origins allowed to open WebSocket connections.
Default: derived from PHX_HOST ·
Example: tymeslot.yourdomain.com,app.example.com
ANALYTICS_SALT_SECRET
Optional
Keys the cookie-less daily visitor fingerprint used by booking analytics. Only required when booking analytics is enabled — most self-hosters leave analytics off and never need it. When the feature is enabled, this variable becomes mandatory and the app fails fast at boot if it is missing. Generate it once and keep it constant across deployments — changing it re-hashes the same visitor and double-counts uniques.
Default: none ·
Example: openssl rand -base64 48
🗄️ Database
DATABASE_HOST
Optional
PostgreSQL server hostname.
Default: localhost ·
Example: db.internal
DATABASE_PORT
Optional
PostgreSQL server port.
Default: 5432 ·
Example: 5432
POSTGRES_DB
Optional
Database name.
Default: tymeslot ·
Example: tymeslot
POSTGRES_USER
Optional
Database user.
Default: tymeslot ·
Example: tymeslot
POSTGRES_PASSWORD
Required
Database password.
Default: none ·
Example: a_secure_password
DATABASE_POOL_SIZE
Optional
PostgreSQL connection pool size. Reduce for resource-constrained environments.
Default: 60 ·
Example: 20
✉️ Email
EMAIL_ADAPTER
Optional
Email delivery method. Use smtp
or postmark. Defaults to
smtp
if not set.
Default: smtp ·
Example: smtp
Cloudron Users
On Cloudron, email is configured automatically via the sendmail addon. You don't need to set
EMAIL_ADAPTER, SMTP_*, or
EMAIL_FROM_*
variables. Set
EMAIL_ADAPTER
explicitly only if you want to use a different provider.
EMAIL_FROM_NAME
Required
Sender display name shown in email clients.
Default: none ·
Example: Your Company
EMAIL_FROM_ADDRESS
Required
Sender email address.
Default: none ·
Example: hello@yourdomain.com
EMAIL_SUPPORT_ADDRESS
Optional
Support contact email. Defaults to
EMAIL_FROM_ADDRESS
if not set.
Default: EMAIL_FROM_ADDRESS ·
Example: support@yourdomain.com
SMTP_HOST
Optional
Required for SMTP adapter. SMTP server hostname.
Default: none ·
Example: smtp.gmail.com
SMTP_PORT
Optional
SMTP server port. Use 587 for STARTTLS (recommended) or 465 for SMTPS.
Default: 587 ·
Example: 587
SMTP_USERNAME
Optional
Required for SMTP adapter. SMTP authentication username.
Default: none ·
Example: hello@yourdomain.com
SMTP_PASSWORD
Optional
Required for SMTP adapter. SMTP authentication password or app password.
Default: none ·
Example: your_smtp_password
POSTMARK_API_KEY
Optional
Required for Postmark adapter. Server API token from your Postmark dashboard.
Default: none ·
Example: your-server-api-token
🔑 Google OAuth
ENABLE_GOOGLE_AUTH
Optional
Set to true
to show a "Sign in with Google" button on the login page.
Default: false ·
Example: true
GOOGLE_CLIENT_ID
Optional
Required to use Google Login, Google Calendar, or Google Meet. OAuth client ID from Google Cloud Console.
Default: none ·
Example: 123456-abc.apps.googleusercontent.com
GOOGLE_CLIENT_SECRET
Optional
Required to use Google features. OAuth client secret from Google Cloud Console.
Default: none ·
Example: GOCSPX-your-secret
GOOGLE_STATE_SECRET
Optional
Required to use Google features. Random secret for OAuth CSRF state verification.
Default: none ·
Example: openssl rand -hex 32
🔑 Microsoft OAuth
OUTLOOK_CLIENT_ID
Optional
Required to use Outlook Calendar or Microsoft Teams. Azure app Application (client) ID.
Default: none ·
Example: your-azure-app-client-id
OUTLOOK_CLIENT_SECRET
Optional
Required to use Microsoft features. Azure app client secret value.
Default: none ·
Example: your-client-secret-value
OUTLOOK_STATE_SECRET
Optional
Required to use Microsoft features. Random secret for OAuth CSRF state verification.
Default: none ·
Example: openssl rand -hex 32
🎥 Video Conferencing
Tymeslot can attach a Zoom meeting to confirmed bookings. Self-hosters create their own Zoom Marketplace app — see the Zoom integration guide for the full walkthrough.
ZOOM_CLIENT_ID
Optional
Required to use Zoom. Marketplace app Client ID.
Default: none ·
Example: your-zoom-client-id
ZOOM_CLIENT_SECRET
Optional
Required to use Zoom. Marketplace app Client Secret.
Default: none ·
Example: your-zoom-client-secret
ZOOM_STATE_SECRET
Optional
Required to use Zoom. Random secret for OAuth CSRF state verification.
Default: none ·
Example: openssl rand -hex 32
ZOOM_DEAUTH_SECRET
Optional
Required to use Zoom. Marketplace Secret Token used to verify the HMAC-SHA256
signature on Zoom's deauthorization webhook posted to
/auth/zoom/deauthorize
. Find it under Features → Deauthorization Notification in the Marketplace app.
Default: none ·
Example: <marketplace secret token>
📅 Calendar Sync
WEBHOOK_BASE_URL
Optional
Public HTTPS base URL that Google and Microsoft call back to for real-time
calendar change notifications (Google push channels and Outlook Graph
subscriptions). Usually the same as your PHX_HOST
with an https://
prefix — scheme and host only, no trailing slash or path.
When unset, calendar sync falls back to polling every 15 minutes — fully functional,
just not instant. Set it only when the host is reachable from the public internet
over HTTPS: providers run a validation handshake against the URL when a subscription
is registered, so localhost, private-network, and NAT deployments should leave it unset.
Existing calendar connections adopt push when their owner reconnects; new connections
register automatically.
Default: none (polling fallback) ·
Example: https://tymeslot.yourdomain.com
💳 Meeting Payments (Stripe)
MEETING_PAYMENTS_ENABLED
Optional
Opt-in switch for meeting payments. Exposes the payments dashboard and the per-event-type payment toggle. Requires your instance to be registered as a Stripe Connect platform — see the Stripe Payments Setup guide .
Default: false ·
Example: true
STRIPE_SECRET_KEY
Optional
Your platform's Stripe secret key. Required when MEETING_PAYMENTS_ENABLED=true;
the webhook secrets below are only read when this is set.
Default: unset ·
Example: sk_live_51...
STRIPE_CONNECT_WEBHOOK_SECRET
Optional
Signing secret of the Connect webhook endpoint
(/webhooks/stripe/connect) that receives
connected-account events. Required to verify checkout, refund and dispute events
for meeting payments.
Default: unset ·
Example: whsec_...
MEETING_PAYMENTS_APPLICATION_FEE_BP
Optional
Optional platform fee in basis points (100 = 1%), taken from each charge. Defaults to 0, so no platform cut is taken unless you opt in. Range 0 to 10000.
Default: 0 ·
Example: 100
🔑 GitHub OAuth
ENABLE_GITHUB_AUTH
Optional
Set to true
to show a "Sign in with GitHub" button on the login page.
Default: false ·
Example: true
GITHUB_CLIENT_ID
Optional
Required for GitHub Login. OAuth app client ID from GitHub Developer settings.
Default: none ·
Example: your_client_id
GITHUB_CLIENT_SECRET
Optional
Required for GitHub Login. OAuth app client secret.
Default: none ·
Example: your_client_secret
🔑 Generic OAuth / OIDC SSO
ENABLE_OAUTH_AUTH
Optional
Set to true
to show an "SSO" button on the login page.
Default: false ·
Example: true
Cloudron Users
On Cloudron, SSO is enabled automatically via the OIDC addon — users can log in with their Cloudron account. You don't need to set any
OAUTH_*
variables. Set
ENABLE_OAUTH_AUTH=false
to disable SSO entirely.
OAUTH_CLIENT_ID
Optional
OAuth 2.0 client ID registered with your identity provider.
Default: none ·
Example: tymeslot
OAUTH_CLIENT_SECRET
Optional
OAuth 2.0 client secret from your identity provider.
Default: none ·
Example: your-client-secret
OAUTH_PROVIDER_URL
Optional
Base URL of your identity provider. Used as the OAuth 2.0
site
parameter.
Default: none ·
Example: https://idp.example.com
OAUTH_AUTHORIZE_URL
Optional
Full URL of the authorization endpoint.
Default: none ·
Example: https://idp.example.com/authorize
OAUTH_TOKEN_URL
Optional
Full URL of the token endpoint.
Default: none ·
Example: https://idp.example.com/token
OAUTH_USERINFO_URL
Optional
Full URL of the userinfo endpoint. Must return a JSON object with a
sub
claim (or id/user_id
if OAUTH_ALLOW_ID_FALLBACK
is enabled).
Default: none ·
Example: https://idp.example.com/userinfo
OAUTH_SCOPE
Optional
Space-separated list of OAuth scopes to request.
Default: openid email profile ·
Example: openid email profile groups
OAUTH_ALLOW_ID_FALLBACK
Optional
Set to true
to accept id
or user_id
claims when the IdP does not return a standard sub
claim. Only enable this for non-OIDC providers.
Default: false ·
Example: true
🛡️ reCAPTCHA
RECAPTCHA_SITE_KEY
Optional
Required to enable reCAPTCHA. v3 site key from Google reCAPTCHA admin console.
Default: none ·
Example: 6Le-your-site-key
RECAPTCHA_SECRET_KEY
Optional
Required to enable reCAPTCHA. v3 secret key from Google reCAPTCHA admin console.
Default: none ·
Example: 6Le-your-secret-key
RECAPTCHA_SIGNUP_ENABLED
Optional
Enable reCAPTCHA score verification on the signup form.
Default: false ·
Example: true
RECAPTCHA_SIGNUP_MIN_SCORE
Optional
Minimum reCAPTCHA score (0.0–1.0) required to pass signup. Higher is more strict.
Default: 0.3 ·
Example: 0.5
RECAPTCHA_BOOKING_ENABLED
Optional
Enable reCAPTCHA score verification on booking forms.
Default: false ·
Example: true
RECAPTCHA_BOOKING_MIN_SCORE
Optional
Minimum reCAPTCHA score required to submit a booking.
Default: 0.3 ·
Example: 0.3
RECAPTCHA_EXPECTED_HOSTNAMES
Optional
Comma-separated list of hostnames from which reCAPTCHA tokens are accepted. Prevents token replay attacks.
Default: none ·
Example: tymeslot.yourdomain.com
✈️ Telegram Notifications
TELEGRAM_BOT_TOKEN
Optional
Bot token from @BotFather. Setting this variable enables shared bot mode — all three Telegram variables must be set together. The application refuses to start if the token is set but the other two are missing.
Default: none ·
Example: 123456789:ABCdef...
TELEGRAM_BOT_USERNAME
Optional
Username of the bot (without the @
prefix). Required when TELEGRAM_BOT_TOKEN
is set.
Default: none ·
Example: MyTymeslotBot
TELEGRAM_WEBHOOK_SECRET
Optional
Random secret passed to Telegram's setWebhook
API and verified on every incoming webhook call. Required when
TELEGRAM_BOT_TOKEN
is set.
Default: none ·
Example: openssl rand -hex 32
TELEGRAM_ENABLED
Optional
Set to true
to enable Telegram in own-bot mode (each user supplies their own bot token and chat ID). Only effective when
TELEGRAM_BOT_TOKEN
is not
set — setting the token automatically enables shared bot mode regardless of this flag.
Default: false ·
Example: true
💬 Slack Notifications
SLACK_CLIENT_ID
Optional
Slack App client ID from api.slack.com/apps. Setting this variable enables Slack notifications and unlocks OAuth mode — users see a one-click "Add to Slack" button. Must be paired with SLACK_CLIENT_SECRET.
Default: none ·
Example: 1234567890.1234567890
SLACK_CLIENT_SECRET
Optional
Slack App client secret from the same page. Required alongside
SLACK_CLIENT_ID
to complete the OAuth code-for-token exchange.
Default: none ·
Example: abcdef0123456789abcdef0123456789
SLACK_ENABLED
Optional
Set to true
to enable Slack in webhook-URL-only mode (each user pastes their own Incoming Webhook URL). Ignored when
SLACK_CLIENT_ID
is set — OAuth mode includes webhook-URL support automatically.
Default: false ·
Example: true
🚨 Admin Alerts
ADMIN_ALERTS_ENABLED
Optional
Set to true
to receive operational alert emails for webhook processing failures, integration health issues, and background job errors. Requires
ADMIN_ALERT_EMAIL
to be set.
Default: false ·
Example: true
ADMIN_ALERT_EMAIL
Optional
Recipient address that admin alert emails are delivered to. Required when
ADMIN_ALERTS_ENABLED=true
— without it, alerts are logged but no email is sent.
Default: none ·
Example: admin@yourdomain.com
🔀 HTTP Proxy
HTTPS_PROXY
Optional
Route HTTPS outbound requests through this proxy. Also accepts lowercase https_proxy.
Default: none ·
Example: http://proxy.corp.com:3128
HTTP_PROXY
Optional
Route HTTP outbound requests through this proxy. Also accepts lowercase http_proxy.
Default: none ·
Example: http://proxy.corp.com:3128
NO_PROXY
Optional
Comma-separated list of hosts, IP addresses, or CIDR ranges that bypass the proxy. Also accepts lowercase no_proxy.
Default: none ·
Example: localhost,127.0.0.1,10.0.0.0/8
🛡️ Outbound Network (SSRF)
In production, outbound requests to hosts that resolve to a private, loopback, or link-local address are blocked to prevent server-side request forgery. If you self-host integrations on a private network, the switches below opt specific subsystems out. Both default to blocking; leave them unset unless you genuinely run those services on an internal network.
ALLOW_PRIVATE_IPS_FOR_CALENDAR
Optional
Permit calendar (CalDAV) and self-hosted video (e.g. MiroTalk) connections whose hostname resolves to a private address. Does not affect webhooks.
Default: false ·
Example: true
ALLOW_PRIVATE_IPS_FOR_WEBHOOKS
Optional
Permit outbound webhook deliveries to URLs that resolve to a private address. Separate from the calendar switch, so relaxing calendar or video SSRF does not also open webhooks to internal hosts.
Default: false ·
Example: true
🌐 Clustering
DNS_CLUSTER_QUERY
Optional
DNS query used for Erlang cluster node discovery in multi-node deployments.
Default: none ·
Example: tymeslot.internal
Minimum Configuration
A minimal Docker deployment only requires:
SECRET_KEY_BASE, PHX_HOST, POSTGRES_PASSWORD, and email configuration (EMAIL_FROM_NAME, EMAIL_FROM_ADDRESS, and SMTP or Postmark credentials). All other variables have defaults or are feature-specific.
❓ Frequently Asked Questions
What is the minimum set of environment variables I need to run Tymeslot?
For a Docker deployment you need five variables to start the application:
-
SECRET_KEY_BASE— required for session signing -
PHX_HOST— your public domain name -
POSTGRES_PASSWORD— the only truly required database variable; hostname, name, and user all have defaults -
EMAIL_FROM_NAMEandEMAIL_FROM_ADDRESS— required for outbound email
Plus credentials for your chosen email adapter — SMTP variables if using the default adapter, or
POSTMARK_API_KEY
if using Postmark.
How do I generate a value for SECRET_KEY_BASE?
Run either of these commands and paste the output as the variable value:
mix phx.gen.secret
— requires an Elixir installation
openssl rand -base64 64 | tr -d '\n'
— works on any system with OpenSSL
The value must be at least 64 characters long. Never reuse a value across environments and never commit it to version control.
Can I use a .env file instead of setting environment variables directly?
Yes, in three different ways depending on how you deploy:
-
Docker Compose:
a
.envfile next to yourdocker-compose.ymlis auto-loaded by Compose and substituted into the file. -
Standalone release / Docker image:
Tymeslot reads
$RELEASE_ROOT/.envat boot. Mount or bake a.envinto the release directory and any keys not already set in the shell are loaded from it. -
Cloudron:
Tymeslot reads
/app/data/.envat boot — the persistent data volume so the file survives upgrades. Place or edit it viacloudron execorcloudron push.
In every case, shell-supplied variables (set via the platform's CLI or dashboard) take precedence over
.env
entries — the file is a default that the environment can override per-key. Malformed
.env
files are skipped with a warning rather than crashing the boot.
Never commit a
.env
file containing secrets to a public repository.
What format should DATABASE_URL be in?
Tymeslot's Docker deployment uses individual variables (DATABASE_HOST, POSTGRES_DB, etc.) rather than a single connection URL. If you are on Cloudron, the platform injects its own
CLOUDRON_POSTGRESQL_*
variables automatically — you do not need to set any database variables manually.
If your hosting platform provides a single URL and you need to break it apart, the standard PostgreSQL format is:
postgres://username:password@hostname:5432/database_name
I changed an environment variable but the application behaviour did not change — why?
Environment variables are read at startup only. A running container retains the values it was started with regardless of any later changes to your
.env
file or platform configuration.
Restart the container after every environment variable change:
docker-compose restart tymeslot
(or a full
docker-compose up -d
to pick up changes to the Compose file itself).
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