Hooks

Hooks are for logs, metrics, tracing, and retry visibility.

const email = createEmailClient({
  adapters: [resend({ apiKey: process.env.RESEND_API_KEY! })],
  hooks: {
    beforeSend(event) {
      console.log("email.send", event.provider, event.message.subject);
    },
    afterSend(event) {
      console.log("email.sent", event.response.id);
    },
    onRetry(event) {
      console.warn("email.retry", event.provider, event.nextAttempt);
    },
    onError(event) {
      console.error("email.error", event.provider, event.error);
    },
  },
});

Hook events

Each hook receives:

afterSend also receives response. onRetry receives nextAttempt and delayMs. onError receives error.

Observe retries and fallback

Hooks expose the send pipeline without changing adapter code:

• beforeSend runs for each adapter attempt.
• onRetry shows retry scheduling for the same adapter.
• onError shows adapter failures before fallback may continue.
• afterSend shows the adapter that actually succeeded.

For safer default redaction, use the observability plugin.

Keep logs safe

Do not log API keys, SMTP passwords, raw tokens, full message bodies, or unnecessary recipient data. For most production logs, routing name, status, subject category, template name, and message ID are enough.