Go

Idiomatic Go client. Methods on each resource (Client.Emails, Client.Contacts, ...) talk directly to the JSON API.

Install

go get github.com/sevk-io/sevk-go

Initialize

sevk.New creates a client from your API key.

package main

import "github.com/sevk-io/sevk-go"

func main() {
    client := sevk.New("sevk_full_xxxxxxxx")
    _ = client
}

Send Email

HTML body

package main

import (
    "fmt"
    "log"

    "github.com/sevk-io/sevk-go"
)

func main() {
    client := sevk.New("sevk_full_xxxxxxxx")

    text := "Thanks for signing up."
    result, err := client.Emails.Send(sevk.SendEmailParams{
        From:    "sevk <[email protected]>",
        To:      sevk.StringOrList{"[email protected]"},
        Subject: "Welcome",
        HTML:    "<h1>Welcome</h1><p>Thanks for signing up.</p>",
        Text:    &text,
        ReplyTo: sevk.StringOrList{"[email protected]"},
    })
    if err != nil {
        log.Fatal(err)
    }

    switch response := result.(type) {
    case sevk.SendEmailIDResponse:
        fmt.Println(response.ID)
    case sevk.SendEmailIDsResponse:
        fmt.Println(response.IDs)
    }
}

With attachments

result, err := client.Emails.Send(sevk.SendEmailParams{
    From:    "sevk <[email protected]>",
    To:      sevk.StringOrList{"[email protected]"},
    Subject: "Your invoice",
    HTML:    "<p>Invoice attached.</p>",
    Attachments: []sevk.EmailAttachment{
        {
            Filename:    "invoice.pdf",
            Content:     base64Pdf,
            ContentType: "application/pdf",
        },
    },
})

Send Bulk

result, err := client.Emails.SendBulk([]sevk.SendBulkEmailParams{
    {From: "sevk <[email protected]>", To: "[email protected]", Subject: "Welcome", HTML: "<p>Hi 1</p>"},
    {From: "sevk <[email protected]>", To: "[email protected]", Subject: "Welcome", HTML: "<p>Hi 2</p>"},
})
if err != nil {
    log.Fatal(err)
}

fmt.Printf("ok=%d failed=%d\n", result.Success, result.Failed)

Contacts

contact, err := client.Contacts.Create(sevk.CreateContactParams{
    Email: "[email protected]",
    Data:  map[string]interface{}{"firstName": "John", "plan": "pro"},
})
if err != nil { log.Fatal(err) }

_, _ = client.Contacts.Get(contact.ID)

_, _ = client.Contacts.Update(contact.ID, sevk.UpdateContactParams{
    Data: sevk.NewNullable(map[string]interface{}{"plan": "enterprise"}),
})

limit := 50
page, _ := client.Contacts.List(&sevk.ListContactsParams{Limit: &limit})
for _, c := range page.Items {
    fmt.Println(c.Email)
}

_, _ = client.Contacts.Delete(contact.ID)

Clear Fields

Some update fields distinguish between leaving a value unchanged and clearing it with JSON null. These fields use *sevk.Nullable[T]: leave them nil to keep the current value, use sevk.NewNullable(v) to set a value, or sevk.Null[T]() to send null.

client.Contacts.Update(contactID, sevk.UpdateContactParams{
    Data: sevk.NewNullable(map[string]interface{}{"plan": "pro"}),
})

client.Contacts.Update(contactID, sevk.UpdateContactParams{
    Data: sevk.Null[map[string]interface{}](),
})

client.Broadcasts.Update(broadcastID, sevk.UpdateBroadcastParams{
    ReplyTo:       sevk.Null[string](),
    ScheduledAt:   sevk.Null[string](),
    OpenTracking:  sevk.Null[bool](),
    ClickTracking: sevk.Null[bool](),
    Variants:      sevk.Null[[]sevk.VariantInput](),
})

For broadcasts, null clears ReplyTo and ScheduledAt, resets OpenTracking and ClickTracking to the domain default, and removes A/B test variants. BulkUpdateContact.Data works the same way as UpdateContactParams.Data.

Audiences

audience, _ := client.Audiences.Create(sevk.CreateAudienceParams{
    Name: "Newsletter",
})

_, _ = client.Audiences.AddContacts(audience.ID, []string{
    "b2c3d4e5-f678-4901-abcd-ef1234567890",
    "b2c3d4e5-f678-4901-abcd-ef1234567891",
})

page, _ := client.Audiences.ListContacts(audience.ID, nil)
for _, c := range page.Items {
    fmt.Println(c.Email)
}

Render Markup

package main

import (
    "fmt"

    "github.com/sevk-io/sevk-go/markup"
)

func main() {
    html := markup.Render(`
        <section padding="32px">
          <heading level="1">Hello</heading>
          <paragraph>Rendered locally.</paragraph>
        </section>
    `)

    fmt.Println(html)
}

Error Handling

SDK errors flow through *sevk.Error. Use errors.As to inspect the API status, code, message, fields, details, response body, and retry delay.

import "errors"

_, err := client.Emails.Send(sevk.SendEmailParams{
    From:    "[email protected]",
    To:      sevk.StringOrList{"not-an-email"},
    Subject: "Test",
    HTML:    "Hi",
})

var sevkErr *sevk.Error
if errors.As(err, &sevkErr) {
    fmt.Println(sevkErr.StatusCode, sevkErr.Code, sevkErr.Message)
} else if err != nil {
    log.Fatal(err)
}