Resend email for GoCommerce

What it does

Configuration

Only the API key is required; everything else has a default that still sends. Set it in Config from your own main(), or leave Config empty and type it under Notifications › Setup Email.

The module reads its Config struct, not the environment. The variable names are the ones the package’s own example or the reference binary uses; in your own main() you choose where each value comes from. Where a setting has a panel label, the admin’s settings drawer can hold it too, and a value typed there wins over Config.

Setting it up

1. Create an API keyIn Resend. Verifying a sending domain can wait: until it is done, mail goes from onboarding@resend.dev, Resend’s address for accounts without one.
2. Install the moduleImport it and pass resend.New to gocommerce.New, as below — or run the reference binary with -resend, which reads RESEND_API_KEY, RESEND_FROM and RESEND_FROM_NAME.
3. Switch it onA key in Config starts it switched on. Otherwise switch it on under Notifications › Setup Email and paste the key there; it counts on the next message, with no restart.
4. Edit the wordingSubjects and bodies are the engine’s templates, edited under Notifications › Setup Email. Place an order and the confirmation goes out.

import (
	"os"

	"github.com/itswadesh/gocommerce/core"
	resend "github.com/itswadesh/gocommerce/ext/notify-resend"
)

app, err := gocommerce.New(cfg,
	resend.New(resend.Config{APIKey: os.Getenv("RESEND_API_KEY")}),
)

How it works

• The engine’s words

  Subject and body come from the engine’s templates at send time — the panel’s edit if there is one, Config’s Subjects and Bodies if not, the engine’s default otherwise — rendered with Go’s text/template over the event’s flat data.

• Every message written down

  Sent, with the id Resend filed it under; rejected, with Resend’s reason; or not attempted because there is no key. A store cannot look healthy for months while nobody receives anything.

• Rejections settle, outages retry

  A 4xx other than 429 is logged and settled: a bad address will be rejected again. Unreachable, 429 or 5xx is returned as an error, and the engine retries the notification with backoff.

• Overrides checked at boot

  A Subjects or Bodies template that does not parse stops the store booting, rather than failing on the first sale.

• Only events with wording

  An event with no email template is skipped, not an error, so another module can add events this one has never heard of.

• Settings without a restart

  The panel’s values are read on every send. The engine keeps a row per message in its notification log, and an operator can resend one from there.

What it does not do

Read these before an order depends on it. No store is known to run GoCommerce in production yet, so these come from the code, not from anyone’s experience.

• Config’s From is shadowedThe panel’s From field defaults to onboarding@resend.dev and is read before Config, so a sender set only in code or RESEND_FROM is not used — type it into the panel. For the same reason the sent line’s default_sender flag reads false even when mail goes from the onboarding address.
• Plain text onlyEach email is sent as text. There is no HTML body and no attachment.
• Amounts in minor unitsThe engine hands templates totals in minor units — 49900, not 499.00 — and a store that wants them formatted edits the template.
• Two backends, two emailsEvery configured email backend gets every message. With Resend and SendGrid both switched on, a shopper gets two; and a retry after one fails re-sends through both.
• Refusals count as sentA message Resend refuses returns no error, so the engine’s notification log records it as sent. The refusal is only in the application log.
• No bounce trackingThe module registers no webhook. Bounces, complaints and opens stay in Resend.