Email (Resend)

BraDypUS sends two kinds of transactional emails — password reset and self-registration confirmation — through Resend, a transactional email API. There is no SMTP option and no local mail server support: Mail\Mailer talks to the Resend HTTP API directly.

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How it works

Mail\Mailer::isConfigured()
  → true only when RESEND_API_KEY and MAIL_FROM_ADDRESS are both set

Mail\Mailer::send($to, $subject, $html)
  → POSTs to https://api.resend.com/emails
  → throws MailException on any network/HTTP error

BraDypUS is multi-tenant: one Resend account/API key covers every app hosted on the instance — set once via environment variables, not per-app config (the same reasoning as one PHP/DB backend serving many apps). A deployer who doesn't want to run email just leaves the key unset; the features that need it then report themselves as unavailable instead of silently failing.

Two callers use Mail\Mailer::send(), both in Controllers\Login:

Flow	Trigger	Templates (Mail\Templates)
Self-registration	POST /api/auth/register (only when allow_self_registration is on for the app — see App settings)	registrationConfirmation() (to the new user) + registrationAdminNotice() (to every admin/super-admin)
Password reset	POST /api/auth/password-reset/request	passwordReset()

Email language is picked per-request from the Accept-Language header (Templates::langFromHeader()) — it is not the app's configured default language (see Config & UAC) or the recipient's own locale preference, since neither is known at the point these emails are sent.

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Configuration

Set these environment variables on the bdus-api container (or the host PHP process) — see Deploy → environment variables for how to pass them through Docker Compose:

Variable	Required	Description
RESEND_API_KEY	Yes	API key from your Resend account. Unset = email features report as unavailable.
MAIL_FROM_ADDRESS	Yes	Sender address. Must be on a domain verified in Resend.
MAIL_FROM_NAME	No (default BraDypUS)	Sender display name.

There is no per-app configuration: every app on the instance shares the same sender identity and quota.

Setup

1. Create a Resend account and verify a sending domain (Resend walks you through the DNS records).
2. Create an API key in the Resend dashboard.
3. Set RESEND_API_KEY, MAIL_FROM_ADDRESS (an address on the verified domain), and optionally MAIL_FROM_NAME on the bdus-api container.
4. Restart bdus-api so the new environment variables are picked up.

No restart of individual apps is needed — Mail\Mailer::isConfigured() reads the environment on every call.

What's gated on this

• Self-registration — the Allow self-registration toggle in App settings is disabled, with an explanatory note, whenever Mail\Mailer::isConfigured() is false: turning registration on without a way to email the new user (and notify admins) would silently strand accounts in the Pending privilege level forever.
• Password reset — POST /api/auth/password-reset/request returns email_not_configured instead of sending anything.

Both checks happen server-side on every request — there is no cached "email is configured" state to go stale.

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Security notes

• The Resend API key is a single instance-wide secret — treat it like any other credential in docker-compose.yml/.env, not like the per-app OAuth or DB credentials in projects/{app}/config.json.
• Mail\Mailer::send() never logs the API key; a MailException message is safe to write to the application log but was never meant to be shown to the end user verbatim (callers translate it to a generic error code).
• Password-reset tokens are single-use and time-limited — see Controllers\Login::requestPasswordReset()/confirmPasswordReset() and the reset_token_hash/reset_token_expires columns added by M040.