Telnyx WhatsApp Business API - Go

Installation

go get github.com/team-telnyx/telnyx-go

Setup

import (
	"context"
	"fmt"
	"os"

	"github.com/team-telnyx/telnyx-go"
	"github.com/team-telnyx/telnyx-go/option"
)

client := telnyx.NewClient(option.WithAPIKey(os.Getenv("TELNYX_API_KEY")))

All examples below assume client is already initialized as shown above.

Error Handling

All API calls can fail with network errors, rate limits (429), validation errors (422), or authentication errors (401). Always handle errors in production code:

ctx := context.TODO()

response, err := client.Messages.SendWhatsapp(ctx, telnyx.MessageSendWhatsappParams{
	From: telnyx.String("+19452940762"),
	To:   telnyx.String("+18005551234"),
	Type: telnyx.F(telnyx.MessageSendWhatsappParamsTypeWhatsapp),
	WhatsappMessage: telnyx.F(telnyx.MessageSendWhatsappParamsWhatsappMessage{
		Type: telnyx.F("text"),
		Text: telnyx.F(map[string]interface{}{
			"body": "Hello from Telnyx!",
		}),
	}),
})
if err != nil {
	var apiErr *telnyx.Error
	if errors.As(err, &apiErr) {
		fmt.Printf("API error: %d - %s\n", apiErr.StatusCode, apiErr.Message)
	}
	return err
}
fmt.Println(response.Data.ID)

Common error codes: 401 invalid API key, 403 insufficient permissions, 404 resource not found, 422 validation error (check field formats), 429 rate limited (retry with exponential backoff).

WhatsApp-Specific Errors

• 40008 — Meta catch-all error. Check template parameters, phone number formatting, and 24-hour window rules.
• 131047 — Message failed to send during the 24-hour window. The customer hasn't messaged you first (for non-template messages).
• 131026 — Recipient phone number is not a WhatsApp user.
• 132000 — Template parameter count mismatch. Ensure the number of parameters matches the template definition.
• 132015 — Template paused or disabled by Meta due to quality issues.

Important Notes

• Phone numbers must be in E.164 format (e.g., +13125550001). Include the + prefix and country code.
• Template messages can be sent anytime. Free-form (session) messages can only be sent within a 24-hour window after the customer last messaged you.
• Template IDs: You can reference templates by Telnyx UUID (template_id) instead of name + language. When template_id is provided, name and language are resolved automatically.
• Pagination: List endpoints return paginated results. Use the auto-paging iterator: iter.Next() in a loop.

Operational Caveats

• The sending phone number must be registered with a WhatsApp Business Account (WABA) and associated with a messaging profile.
• Templates must be in APPROVED status before they can be used for sending.
• Template names must be lowercase with underscores only (e.g., order_confirmation). No spaces, hyphens, or uppercase.
• When creating templates, provide realistic sample values for body parameters — Meta reviewers check these during approval.
• Category selection matters for billing: AUTHENTICATION templates get special pricing but must contain an OTP. UTILITY is for transactional messages. MARKETING for promotional content.
• Meta may reclassify your template category (e.g., UTILITY to MARKETING) which affects billing.

Reference Use Rules

Do not invent Telnyx parameters, enums, response fields, or webhook fields.

• If the parameter, enum, or response field you need is not shown inline in this skill, read references/api-details.md before writing code.
• Before using any operation in ## Additional Operations, read the optional-parameters section and the response-schemas section.
• Before reading or matching webhook fields beyond the inline examples, read the webhook payload reference.

Core Tasks

Send a WhatsApp template message

Send a pre-approved template message. Templates can be sent anytime — no 24-hour window restriction.

client.Messages.SendWhatsapp() — POST /messages/whatsapp

Parameter	Type	Required	Description
From	string (E.164)	Yes	WhatsApp-enabled phone number in +E.164 format
To	string (E.164)	Yes	Recipient phone number in +E.164 format
Type	string	No	Must be WHATSAPP
WhatsappMessage	object	Yes	WhatsApp message object
MessagingProfileID	string (UUID)	No	Messaging profile to use
WebhookURL	string (URL)	No	Callback URL for delivery status updates

// Send by template name + language
ctx := context.TODO()

response, err := client.Messages.SendWhatsapp(ctx, telnyx.MessageSendWhatsappParams{
	From: telnyx.String("+19452940762"),
	To:   telnyx.String("+18005551234"),
	Type: telnyx.F(telnyx.MessageSendWhatsappParamsTypeWhatsapp),
	WhatsappMessage: telnyx.F(telnyx.MessageSendWhatsappParamsWhatsappMessage{
		Type: telnyx.F("template"),
		Template: telnyx.F(telnyx.MessageSendWhatsappParamsWhatsappMessageTemplate{
			Name:     telnyx.String("order_confirmation"),
			Language: telnyx.F(telnyx.MessageSendWhatsappParamsWhatsappMessageTemplateLanguage{
				Code: telnyx.String("en_US"),
			}),
			Components: telnyx.F([]telnyx.MessageSendWhatsappParamsWhatsappMessageTemplateComponent{
				{
					Type: telnyx.F("body"),
					Parameters: telnyx.F([]telnyx.MessageSendWhatsappParamsWhatsappMessageTemplateComponentParameter{
						{Type: telnyx.F("text"), Text: telnyx.String("ORD-12345")},
						{Type: telnyx.F("text"), Text: telnyx.String("March 15, 2026")},
					}),
				},
			}),
		}),
	}),
})
if err != nil {
	log.Fatal(err)
}
fmt.Println(response.Data.ID)

// Send by Telnyx template_id (no name/language needed)
ctx := context.TODO()

response, err := client.Messages.SendWhatsapp(ctx, telnyx.MessageSendWhatsappParams{
	From: telnyx.String("+19452940762"),
	To:   telnyx.String("+18005551234"),
	Type: telnyx.F(telnyx.MessageSendWhatsappParamsTypeWhatsapp),
	WhatsappMessage: telnyx.F(telnyx.MessageSendWhatsappParamsWhatsappMessage{
		Type: telnyx.F("template"),
		Template: telnyx.F(telnyx.MessageSendWhatsappParamsWhatsappMessageTemplate{
			TemplateID: telnyx.String("019cd44b-3a1c-781b-956e-bd33e9fd2ac6"),
			Components: telnyx.F([]telnyx.MessageSendWhatsappParamsWhatsappMessageTemplateComponent{
				{
					Type: telnyx.F("body"),
					Parameters: telnyx.F([]telnyx.MessageSendWhatsappParamsWhatsappMessageTemplateComponentParameter{
						{Type: telnyx.F("text"), Text: telnyx.String("483291")},
					}),
				},
			}),
		}),
	}),
})
if err != nil {
	log.Fatal(err)
}
fmt.Println(response.Data.ID)

Primary response fields:

• response.Data.ID — Message UUID
• response.Data.To[0].Status — queued, sent, delivered, failed
• response.Data.From.PhoneNumber
• response.Data.Type — WHATSAPP

Send a free-form WhatsApp text message

Send a text message within the 24-hour customer service window.

client.Messages.SendWhatsapp() — POST /messages/whatsapp

ctx := context.TODO()

response, err := client.Messages.SendWhatsapp(ctx, telnyx.MessageSendWhatsappParams{
	From: telnyx.String("+19452940762"),
	To:   telnyx.String("+18005551234"),
	Type: telnyx.F(telnyx.MessageSendWhatsappParamsTypeWhatsapp),
	WhatsappMessage: telnyx.F(telnyx.MessageSendWhatsappParamsWhatsappMessage{
		Type: telnyx.F("text"),
		Text: telnyx.F(map[string]interface{}{
			"body": "Your order has shipped!",
		}),
	}),
})
if err != nil {
	log.Fatal(err)
}
fmt.Println(response.Data.ID)

List WhatsApp Business Accounts

client.Whatsapp.BusinessAccounts.List() — GET /v2/whatsapp/business_accounts

ctx := context.TODO()

response, err := client.Whatsapp.BusinessAccounts.List(ctx, telnyx.WhatsappBusinessAccountListParams{})
if err != nil {
	log.Fatal(err)
}
for _, waba := range response.Data {
	fmt.Printf("%s: %s (%s)\n", waba.ID, waba.Name, waba.Status)
}

Primary response fields:

• waba.ID — Telnyx WABA UUID
• waba.WabaID — Meta WABA ID
• waba.Name — Business name
• waba.Status — Account status
• waba.Country — WABA country

List templates for a WABA

client.Whatsapp.Templates.List() — GET /v2/whatsapp/message_templates

Parameter	Type	Required	Description
WabaID	string (UUID)	Yes	Telnyx WABA UUID
Category	string	No	Filter: AUTHENTICATION, MARKETING, UTILITY
Status	string	No	Filter: APPROVED, PENDING, REJECTED, DISABLED

ctx := context.TODO()

response, err := client.Whatsapp.Templates.List(ctx,
	telnyx.WhatsappTemplateListParams{
		WabaID: telnyx.String("019c1ff0-5c30-7f36-8436-730b1d0b0e56"),
		Status: telnyx.String("APPROVED"),
	},
)
if err != nil {
	log.Fatal(err)
}
for _, tmpl := range response.Data {
	fmt.Printf("%s: %s (%s) - %s\n", tmpl.ID, tmpl.Name, tmpl.Category, tmpl.Status)
}

Primary response fields:

• tmpl.ID — Telnyx template UUID (use as template_id when sending)
• tmpl.Name — Template name
• tmpl.Category — AUTHENTICATION, MARKETING, or UTILITY
• tmpl.Language — Language code
• tmpl.Status — APPROVED, PENDING, REJECTED, DISABLED
• tmpl.Components — Template components

Create a message template

client.Whatsapp.Templates.Create() — POST /v2/whatsapp/message_templates

ctx := context.TODO()

response, err := client.Whatsapp.Templates.Create(ctx,
	telnyx.WhatsappTemplateCreateParams{
		WabaID:   telnyx.String("019c1ff0-5c30-7f36-8436-730b1d0b0e56"),
		Name:     telnyx.String("order_shipped"),
		Category: telnyx.String("UTILITY"),
		Language: telnyx.String("en_US"),
		Components: telnyx.F([]telnyx.WhatsappTemplateCreateParamsComponent{
			{
				Type: telnyx.F("BODY"),
				Text: telnyx.String("Your order {{1}} has been shipped and will arrive by {{2}}."),
				Example: telnyx.F(telnyx.WhatsappTemplateCreateParamsComponentExample{
					BodyText: telnyx.F([][]string{{"ORD-12345", "March 20, 2026"}}),
				}),
			},
		}),
	},
)
if err != nil {
	log.Fatal(err)
}
fmt.Printf("Template created: %s (status: %s)\n", response.Data.ID, response.Data.Status)

List phone numbers for a WABA

client.Whatsapp.PhoneNumbers.List() — GET /v2/whatsapp/phone_numbers

ctx := context.TODO()

response, err := client.Whatsapp.PhoneNumbers.List(ctx,
	telnyx.WhatsappPhoneNumberListParams{
		WabaID: telnyx.String("019c1ff0-5c30-7f36-8436-730b1d0b0e56"),
	},
)
if err != nil {
	log.Fatal(err)
}
for _, pn := range response.Data {
	fmt.Printf("%s - quality: %s\n", pn.PhoneNumber, pn.QualityRating)
}

---

Webhook Verification

Telnyx signs webhooks with Ed25519. Always verify signatures in production:

import "github.com/team-telnyx/telnyx-go/webhook"

event, err := webhook.ConstructEvent(
	payload,                                 // []byte — raw request body
	request.Header.Get("telnyx-signature-ed25519"),
	request.Header.Get("telnyx-timestamp"),
	telnyxPublicKey,
)
if err != nil {
	log.Printf("Webhook verification failed: %v", err)
	http.Error(w, "Invalid signature", http.StatusForbidden)
	return
}

Webhooks

These webhook payload fields are inline because they are part of the primary integration path.

Message Delivery Update

Field	Type	Description
data.event_type	enum: message.sent, message.finalized	Delivery status event
data.payload.id	uuid	Message ID
data.payload.to[0].status	string	queued, sent, delivered, read, failed
data.payload.template_id	string	Telnyx template UUID (if template message)
data.payload.template_name	string	Template name (if template message)

Template Status Change

Field	Type	Description
event_type	string	whatsapp.template.approved, whatsapp.template.rejected, whatsapp.template.disabled
payload.template_id	string	Telnyx template UUID
payload.template_name	string	Template name
payload.status	string	New template status
payload.reason	string	Rejection/disable reason

Template Best Practices

• Naming: Use lowercase with underscores. Be descriptive (e.g., appointment_reminder, not msg1).
• Sample values: Provide realistic examples in the example field — Meta reviewers check these.
• Category selection:
  • AUTHENTICATION — OTP/verification codes only. Gets special pricing.
  • UTILITY — Transactional (order updates, shipping, account alerts).
  • MARKETING — Promotional content, offers, newsletters.
• Keep it concise: Meta prefers shorter templates. Avoid unnecessary formatting.
• Parameters: Use {{1}}, {{2}}, etc. for variable content. Always provide the correct number of parameters when sending.

Important Supporting Operations

Operation	SDK Method	Use Case
Get template details	client.WhatsappMessageTemplates.Retrieve()	Check template status
Get business profile	client.Whatsapp.PhoneNumbers.Profile.Retrieve()	View business profile
Configure webhooks	client.Whatsapp.BusinessAccounts.Settings.Update()	Subscribe to events

Additional Operations

Operation	SDK Method	Endpoint	Required Params
Send WhatsApp message	client.Messages.SendWhatsapp()	POST /messages/whatsapp	From, To, WhatsappMessage
List WABAs	client.Whatsapp.BusinessAccounts.List()	GET /v2/whatsapp/business_accounts	—
Get WABA	client.Whatsapp.BusinessAccounts.Retrieve()	GET /v2/whatsapp/business_accounts/:id	WabaID
List templates	client.Whatsapp.Templates.List()	GET /v2/whatsapp/message_templates	WabaID
Get template	client.WhatsappMessageTemplates.Retrieve()	GET /v2/whatsapp_message_templates/:id	TemplateID
Create template	client.Whatsapp.Templates.Create()	POST /v2/whatsapp/message_templates	WabaID, Name, Category, Language, Components
List phone numbers	client.Whatsapp.PhoneNumbers.List()	GET /v2/whatsapp/phone_numbers	WabaID
Configure webhooks	client.Whatsapp.BusinessAccounts.Settings.Update()	PATCH /v2/whatsapp/business_accounts/:id/settings	WabaID