Configuration

All configuration is read from environment variables. A misconfigured deployment fails at boot with a report naming every offending variable, rather than failing requests one at a time later.

Required

Variable	Purpose
DATABASE_URL	PostgreSQL connection string. Must include ?options=-c%20timezone%3DUTC (or +c+timezone...) — see the note below.
AUTH_JWT_SECRET	Signs session tokens. Generate with openssl rand -base64 32.
RESEND_WEBHOOK_SECRET	Verifies inbound mail webhooks.
RESEND_API_KEY	Resend API key, used to send auth emails and receive inbound mail.
AUTH_EMAIL_FROM	From-address for outgoing auth emails.
AUTH_EMAIL_FROM_NAME	Display name for outgoing auth emails.
EMAIL_INBOX_ALLOWED_DOMAINS	Comma-separated list of domains inboxes may be created on. Each must be verified in Resend with its inbound route pointed at POST /api/webhooks/email.

The DATABASE_URL timezone option

Postgres interprets the naive timestamps Prisma sends using the session timezone. Without an explicit UTC session, a host whose local timezone isn't UTC stores every timestamp shifted by its offset. This is enforced at boot, not just documented — a connection string missing the option fails assertConfig().

Common optional variables

Variable	Default	Purpose
REDIS_URL	none	Required if ASYNC_WEBHOOK_PROCESSING_ENABLED=true or AUTH_RATE_LIMIT_ENABLED (on by default)
ASYNC_WEBHOOK_PROCESSING_ENABLED	false	Process inbound mail via a Redis/BullMQ queue instead of inline, for high volume
WEBHOOK_QUEUE_MAX_ATTEMPTS	4	Total attempts (including the first) for an async webhook job
AUTH_RATE_LIMIT_ENABLED	true	Rate-limits login/register — see Rate Limits
EMAIL_VERIFICATION_ENABLED	false	Require a verified email before dashboard access (needs EMAIL_LINK_SIGNING_SECRET + APP_BASE_URL when on)
MCP_ENABLED	false	Expose the MCP server at /api/mcp — see MCP Setup
MCP_ALLOWED_ORIGINS	(empty)	Comma-separated allowed Origins for the MCP transport — absent Origin is allowed by default, present-and-unknown is refused
COMMERCIAL_ENABLED	false	Enable the optional commercial/billing layer (needs Stripe keys when on)
LOG_LEVEL	debug (dev) / info (prod)	Structured log verbosity

The full, authoritative list — every variable, every default, every conditional requirement — lives in .env.example in the repository; this page covers what most self-hosters actually need to set.

Next step

Ready for production? See Production Deployment.