@ydtb/core-layer-resend

Transactional email layer for Anvil apps.

This package currently owns the shared email layer contract plus three provider styles:

• consoleEmail — tests and simple stdout/local logging
• smtpEmail / localInboxEmail — local inbox delivery via SMTP, such as Supabase Inbucket or Mailpit
• resend — production delivery through Resend

The package name is historical; do not interpret it as meaning Resend is the only supported provider.

Email layer contract

Tools and app code send transactional email through the layer, not by importing a provider directly:

import { getLayer } from "@ydtb/core-server"

const email = getLayer("email")
await email.send({
  to: "[email protected]",
  subject: "Welcome",
  body: "Thanks for signing up.",
  html: "<p>Thanks for signing up.</p>",
})

from can be passed per message, or supplied as a provider defaultFrom.

Console provider

Use consoleEmail for tests and for simple local debugging where stdout is enough:

import { consoleEmail } from "@ydtb/core-layer-resend/console"

email: consoleEmail({ silent: false })

Use silent: true in tests when you only need the layer contract and do not want log noise.

Local inbox / SMTP provider

Use localInboxEmail for Supabase Inbucket / Mailpit-style local development where developers need a clickable inbox UI:

import { localInboxEmail } from "@ydtb/core-layer-resend/local-inbox"

email: localInboxEmail({
  port: 54324,
  defaultFrom: "YDTB Dev <dev@localhost>",
})

For explicit SMTP settings, use smtpEmail:

import { smtpEmail } from "@ydtb/core-layer-resend/smtp"

email: smtpEmail({
  host: "127.0.0.1",
  port: 54324,
  secure: false,
  defaultFrom: "YDTB Dev <dev@localhost>",
})

Known local inbox examples in the YDTB deployments workspace:

• apps/main: Supabase local inbox UI on 54324
• apps/dev: Supabase local inbox UI on 54354
• apps/lbl: Supabase local inbox UI on 54364

Check the app's supabase/config.toml for the authoritative local ports before wiring an app.

Resend provider

Use resend for production transactional delivery:

import { resend } from "@ydtb/core-layer-resend"

email: resend({
  apiKey: env.RESEND_API_KEY as string,
  defaultFrom: "YDTB <[email protected]>",
})

Choosing a provider

• Tests: consoleEmail({ silent: true })
• Local development with clickable messages: localInboxEmail(...) or smtpEmail(...)
• Production: resend(...)

Consumer flows such as better-auth password reset emails or scope invitations still need to call getLayer("email").send(...) at their own codepaths.