Email Templates

Email templates allow you to create reusable email designs with dynamic variables that can be populated at send time.

Quick Start

Here’s how to create a template and send an email using it:

package main

import (
	"context"
	"fmt"
	"os"

	"github.com/resend/resend-go/v3"
)

func main() {
	ctx := context.Background()
	apiKey := os.Getenv("RESEND_API_KEY")

	client := resend.NewClient(apiKey)

	// Create a template
	template, err := client.Templates.Create(&resend.CreateTemplateRequest{
		Name:    "welcome-email",
		Alias:   "welcome",
		Subject: "Welcome {{{userName}}}!",
		Html:    "<h1>Hello {{{userName}}}!</h1><p>Welcome to {{{companyName}}}.</p>",
		Variables: []*resend.TemplateVariable{
			{
				Key:           "userName",
				Type:          resend.VariableTypeString,
				FallbackValue: "User",
			},
			{
				Key:           "companyName",
				Type:          resend.VariableTypeString,
				FallbackValue: "Our Company",
			},
		},
	})
	if err != nil {
		panic(err)
	}

	// Publish the template
	_, err = client.Templates.Publish(template.Id)
	if err != nil {
		panic(err)
	}

	// Send email using the template
	sent, err := client.Emails.Send(&resend.SendEmailRequest{
		To: []string{"[email protected]"},
		Template: &resend.EmailTemplate{
			Id: template.Id,
			Variables: map[string]any{
				"userName":    "Alice Johnson",
				"companyName": "Acme Corp",
			},
		},
	})
	if err != nil {
		panic(err)
	}

	fmt.Printf("Email sent: %s\n", sent.Id)
}

EmailTemplate Struct

When sending emails with templates, use the EmailTemplate struct:

string

required

The template ID or alias to use for this email.

variables

map[string]any

Key-value pairs to populate the template placeholders. Values can be strings, numbers, or other JSON-serializable types.

Source: emails.go:17

Creating Templates

Basic Template Creation

ctx := context.Background()

templateParams := &resend.CreateTemplateRequest{
	Name:    "user-welcome-template",
	Alias:   "welcome",
	From:    "[email protected]",
	Subject: "Welcome to {{{companyName}}}, {{{userName}}}!",
	Html: `
		<html>
			<body>
				<h1>Hello {{{userName}}}!</h1>
				<p>Welcome to {{{companyName}}}. We're excited to have you on board.</p>
				<p>You currently have {{{messageCount}}} unread messages waiting for you.</p>
			</body>
		</html>
	`,
	Text: "Hello {{{userName}}}! Welcome to {{{companyName}}}.",
	Variables: []*resend.TemplateVariable{
		{
			Key:           "userName",
			Type:          resend.VariableTypeString,
			FallbackValue: "User",
		},
		{
			Key:           "companyName",
			Type:          resend.VariableTypeString,
			FallbackValue: "Our Company",
		},
		{
			Key:           "messageCount",
			Type:          resend.VariableTypeNumber,
			FallbackValue: 0,
		},
	},
}

template, err := client.Templates.CreateWithContext(ctx, templateParams)
if err != nil {
	panic(err)
}

fmt.Printf("Created template: %s\n", template.Id)

Source: examples/send_email_with_template.go:17

CreateTemplateRequest Fields

name

string

required

The name of the template.

alias

string

A unique alias for the template. Use this to reference the template instead of its ID.

from

string

Default sender email address for this template.

subject

string

Default subject line. Can include template variables like {{{variableName}}}.

replyTo

any

Default reply-to address. Can be a string or array of strings.

html

string

required

HTML content with template variables. Use triple braces {{{variableName}}} for variables.

text

string

Plain text version with template variables.

variables

[]*TemplateVariable

Array of variable definitions used in the template.

All variables referenced in Html or Subject (e.g., {{{userName}}}) must be declared in the Variables array, or the API will return a validation error.

Source: templates.go:28

Template Variables

Each variable in a template must be defined with the TemplateVariable struct:

key

string

required

The variable name (without braces). Must match the placeholder in HTML/subject.

type

VariableType

required

Variable type: VariableTypeString or VariableTypeNumber.

fallbackValue

any

Default value used if no value is provided when sending the email.

Source: templates.go:19

Variable Types

String Variables
Number Variables

{
    Key:           "userName",
    Type:          resend.VariableTypeString,
    FallbackValue: "Guest",
}

Use for: names, email addresses, text content, URLs

{
    Key:           "messageCount",
    Type:          resend.VariableTypeNumber,
    FallbackValue: 0,
}

Use for: counts, prices, quantities, IDs

Publishing Templates

Templates must be published before they can be used:

ctx := context.Background()

// Publish by template ID
publishResp, err := client.Templates.PublishWithContext(ctx, template.Id)
if err != nil {
	panic(err)
}

fmt.Printf("Published template: %s\n", publishResp.Id)

Only published templates can be used to send emails. Unpublished templates are in draft state.

Source: examples/send_email_with_template.go:58

Sending Emails with Templates

Using Template ID

ctx := context.Background()

emailParams := &resend.SendEmailRequest{
	To: []string{"[email protected]"},
	Template: &resend.EmailTemplate{
		Id: "3a76bde0-8f64-4b48-a92f-5f650cc0319d",
		Variables: map[string]any{
			"userName":     "Alice Johnson",
			"companyName":  "Acme Corporation",
			"messageCount": 12,
		},
	},
}

sent, err := client.Emails.SendWithContext(ctx, emailParams)
if err != nil {
	panic(err)
}

fmt.Printf("Sent email: %s\n", sent.Id)

Source: examples/send_email_with_template.go:65

Using Template Alias

You can use the template’s alias instead of its ID:

emailParams := &resend.SendEmailRequest{
	To: []string{"[email protected]"},
	Template: &resend.EmailTemplate{
		Id: "welcome", // Using alias instead of ID
		Variables: map[string]any{
			"userName":     "Bob Smith",
			"companyName":  "Tech Startup Inc",
			"messageCount": 3,
		},
	},
}

sent, err := client.Emails.Send(emailParams)

Using aliases makes your code more maintainable since you don’t need to update IDs when recreating templates.

Source: examples/send_email_with_template.go:84

Overriding Template Fields

You can override template defaults when sending:

emailParams := &resend.SendEmailRequest{
	From:    "[email protected]",         // Override template's From
	To:      []string{"[email protected]"},
	Subject: "Custom Subject Override",     // Override template's Subject
	Bcc:     []string{"[email protected]"},
	ReplyTo: "[email protected]",
	Template: &resend.EmailTemplate{
		Id: template.Id,
		Variables: map[string]any{
			"userName":     "Charlie Brown",
			"companyName":  "Example LLC",
			"messageCount": 7,
		},
	},
}

sent, err := client.Emails.Send(emailParams)

Source: examples/send_email_with_template.go:103

Fields specified in SendEmailRequest take precedence over template defaults.

Managing Templates

Retrieving a Template

ctx := context.Background()

// Get by ID
template, err := client.Templates.GetWithContext(ctx, "3a76bde0-8f64-4b48-a92f-5f650cc0319d")
if err != nil {
	panic(err)
}

// Or get by alias
template, err = client.Templates.Get("welcome")
if err != nil {
	panic(err)
}

fmt.Printf("Template: %s (Status: %s)\n", template.Name, template.Status)
fmt.Printf("Variables: %d\n", len(template.Variables))

Listing Templates

ctx := context.Background()

// List all templates
listResp, err := client.Templates.ListWithContext(ctx, nil)
if err != nil {
	panic(err)
}

fmt.Printf("Found %d templates\n", len(listResp.Data))
for _, tmpl := range listResp.Data {
	fmt.Printf("- %s (alias: %s, status: %s)\n", tmpl.Name, tmpl.Alias, tmpl.Status)
}

// List with pagination
limit := 10
paginatedResp, err := client.Templates.List(&resend.ListOptions{
	Limit: &limit,
})

Updating a Template

ctx := context.Background()

updateParams := &resend.UpdateTemplateRequest{
	Name:    "Updated Welcome Template",
	Subject: "Welcome {{{userName}}} to {{{companyName}}}!",
	Html:    "<h1>Hello {{{userName}}}!</h1><p>Updated content</p>",
	Variables: []*resend.TemplateVariable{
		{
			Key:           "userName",
			Type:          resend.VariableTypeString,
			FallbackValue: "User",
		},
		{
			Key:           "companyName",
			Type:          resend.VariableTypeString,
			FallbackValue: "Our Company",
		},
	},
}

updated, err := client.Templates.UpdateWithContext(ctx, "welcome", updateParams)
if err != nil {
	panic(err)
}

fmt.Printf("Updated template: %s\n", updated.Id)

After updating a template, you must publish it again for changes to take effect in sent emails.

Duplicating a Template

ctx := context.Background()

duplicateResp, err := client.Templates.DuplicateWithContext(ctx, "welcome")
if err != nil {
	panic(err)
}

fmt.Printf("Duplicated template ID: %s\n", duplicateResp.Id)

Deleting a Template

ctx := context.Background()

removeResp, err := client.Templates.RemoveWithContext(ctx, template.Id)
if err != nil {
	panic(err)
}

if removeResp.Deleted {
	fmt.Printf("Deleted template: %s\n", removeResp.Id)
}

Source: examples/send_email_with_template.go:126

Common Use Cases

Welcome Emails

templateParams := &resend.CreateTemplateRequest{
    Name:    "welcome-email",
    Alias:   "welcome",
    Subject: "Welcome to {{{appName}}}, {{{userName}}}!",
    Html: `
        <h1>Welcome {{{userName}}}!</h1>
        <p>Thanks for joining {{{appName}}}.</p>
        <p>Get started by <a href="{{{loginUrl}}}">logging in</a>.</p>
    `,
    Variables: []*resend.TemplateVariable{
        {Key: "userName", Type: resend.VariableTypeString, FallbackValue: "there"},
        {Key: "appName", Type: resend.VariableTypeString, FallbackValue: "our app"},
        {Key: "loginUrl", Type: resend.VariableTypeString},
    },
}

Order Confirmations

templateParams := &resend.CreateTemplateRequest{
    Name:    "order-confirmation",
    Alias:   "order-confirmed",
    Subject: "Order #{{{orderNumber}}} Confirmed",
    Html: `
        <h1>Thank you for your order!</h1>
        <p>Order Number: {{{orderNumber}}}</p>
        <p>Total: ${{{orderTotal}}}</p>
        <p>Items: {{{itemCount}}}</p>
        <p><a href="{{{trackingUrl}}}">Track your order</a></p>
    `,
    Variables: []*resend.TemplateVariable{
        {Key: "orderNumber", Type: resend.VariableTypeString},
        {Key: "orderTotal", Type: resend.VariableTypeNumber},
        {Key: "itemCount", Type: resend.VariableTypeNumber},
        {Key: "trackingUrl", Type: resend.VariableTypeString},
    },
}

Password Reset

templateParams := &resend.CreateTemplateRequest{
    Name:    "password-reset",
    Alias:   "reset-password",
    Subject: "Reset your password",
    Html: `
        <h1>Password Reset Request</h1>
        <p>Hi {{{userName}}},</p>
        <p>Click the link below to reset your password:</p>
        <p><a href="{{{resetUrl}}}">Reset Password</a></p>
        <p>This link expires in {{{expiryMinutes}}} minutes.</p>
    `,
    Variables: []*resend.TemplateVariable{
        {Key: "userName", Type: resend.VariableTypeString},
        {Key: "resetUrl", Type: resend.VariableTypeString},
        {Key: "expiryMinutes", Type: resend.VariableTypeNumber, FallbackValue: 60},
    },
}

Best Practices

Declare All Variables

Always declare variables in the Variables array before using them in HTML:

// ✅ Correct - variable is declared
Html: "<p>Hello {{{userName}}}</p>",
Variables: []*resend.TemplateVariable{
    {Key: "userName", Type: resend.VariableTypeString},
}

// ❌ Wrong - will cause validation error
Html: "<p>Hello {{{userName}}}</p>",
Variables: []*resend.TemplateVariable{},

Use Aliases for Stability

Use template aliases instead of IDs for better code maintainability:

Template: &resend.EmailTemplate{
    Id: "welcome", // Use alias, not "3a76bde0-8f64-4b48-a92f-5f650cc0319d"
    Variables: map[string]any{...},
}

Provide Fallback Values

Always provide sensible fallback values for optional variables:

{
    Key:           "userName",
    Type:          resend.VariableTypeString,
    FallbackValue: "Valued Customer", // Good default
}

Use Triple Braces

Use triple braces {{{variable}}} for template variables to prevent HTML escaping:

Html: "<h1>Hello {{{userName}}}!</h1>" // Correct
// Not: "<h1>Hello {{userName}}!</h1>" // Wrong

Publish After Updates

Remember to publish templates after creating or updating them:

template, _ := client.Templates.Create(params)
client.Templates.Publish(template.Id) // Required!

Next Steps

Sending Emails

Learn the basics of sending emails

Attachments

Add attachments to template emails

Batch Emails

Send templated emails in bulk

Scheduled Emails

Schedule template emails for later

Get Started

Core Features

Advanced

Examples

Quick Start

EmailTemplate Struct

Creating Templates

Basic Template Creation

CreateTemplateRequest Fields

Template Variables

Variable Types

Publishing Templates

Sending Emails with Templates

Using Template ID

Using Template Alias

Overriding Template Fields

Managing Templates

Retrieving a Template

Listing Templates

Updating a Template

Duplicating a Template

Deleting a Template

Common Use Cases

Best Practices

Next Steps

Sending Emails

Attachments

Batch Emails

Scheduled Emails

Build docs developers (and LLMs) love

Get Started

Core Features

Advanced

Examples

​Quick Start

​EmailTemplate Struct

​Creating Templates

​Basic Template Creation

​CreateTemplateRequest Fields

​Template Variables

​Variable Types

​Publishing Templates

​Sending Emails with Templates

​Using Template ID

​Using Template Alias

​Overriding Template Fields

​Managing Templates

​Retrieving a Template

​Listing Templates

​Updating a Template

​Duplicating a Template

​Deleting a Template

​Common Use Cases

​Best Practices

​Next Steps

Sending Emails

Attachments

Batch Emails

Scheduled Emails

Build docs developers (and LLMs) love

Quick Start

EmailTemplate Struct

Creating Templates

Basic Template Creation

CreateTemplateRequest Fields

Template Variables

Variable Types

Publishing Templates

Sending Emails with Templates

Using Template ID

Using Template Alias

Overriding Template Fields

Managing Templates

Retrieving a Template

Listing Templates

Updating a Template

Duplicating a Template

Deleting a Template

Common Use Cases

Best Practices

Next Steps