go-notification

This is the smallest useful program — no frameworks, no extras. Drop it into main.go, set one env var, and it runs.

main.go

package main

import (
    "context"
    "log"
    "os"
    "time"

    "github.com/gopackx/go-notification/notification"
    "github.com/gopackx/go-notification/channel/mail/mailgun"
    "github.com/gopackx/go-notification/message/mail"
)

type User struct {
    ID    int64
    Email string
}

func (u User) RouteNotificationFor(channel string) any {
    if channel == "mail" {
        return u.Email
    }
    return nil
}

type OrderShipped struct {
    OrderID string
}

func (n OrderShipped) Via(u notification.Notifiable) []string {
    return []string{"mail"}
}

func (n OrderShipped) ToMail(u notification.Notifiable) *mail.Message {
    return mail.NewMessage().
        Subject("Your order has shipped").
        Line("Hi there,").
        Line("Your order " + n.OrderID + " is on its way.").
        Action("Track package", "https://example.com/track/"+n.OrderID).
        Line("Thanks for shopping with us.")
}

func main() {
    notifier := notification.New(notification.Config{})

    notifier.RegisterChannel("mail", mailgun.New(mailgun.Config{
        Domain: "mg.example.com",
        APIKey: os.Getenv("MAILGUN_API_KEY"),
        From:   "noreply@example.com",
    }))

    ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
    defer cancel()

    user := User{ID: 1, Email: "customer@example.com"}

    if err := notifier.Send(ctx, user, OrderShipped{OrderID: "A-1024"}); err != nil {
        log.Fatalf("send failed: %v", err)
    }

    // Give the async worker a moment to flush before the program exits.
    notifier.Close(ctx)
    log.Println("done")
}

Run it

terminal.sh

export MAILGUN_API_KEY=key-xxxx
go run .

What's happening

notification.New() spins up a worker pool with sane defaults — async sends, exponential-backoff retries, 30s timeout.
RegisterChannel("mail", ...) wires up one driver under one name.
Send() calls OrderShipped.Via() to get channel names, then for each one calls ToMail() to build the message and dispatches to the Mailgun driver.
Close() waits for in-flight sends to finish. Without it, a short program may exit before the async send completes.

Multi-Channel Example — fan one notification across mail + WhatsApp + database.
In-App Notifications — add a notification center backed by the database channel.

Basic Example

main.go

Run it

What's happening

Next