Twilio · SMS and voice

Twilio integration: SMS and voice from your system

Twilio integration means your backend sends SMS or starts a call via Twilio, and status — delivered, undelivered, answered — comes back as a webhook. Twilio wins on one global API for SMS, voice and WhatsApp. In Denmark a local gateway often wins on price per SMS and delivery to Danish numbers. See [GatewayAPI](/articles/integrations/gatewayapi-integration). One-time codes, “your technician is 20 minutes away” and two-way YES to a slot are use cases that hold. Voice as your main PBX is not, in the first version. Sender id, stop-text on marketing and idempotency must be built regardless of vendor.

Secrets stay out of git. Never a CPR number in the SMS body. Never a token in the query string. The same discipline as Vonage and Plivo. Automation that sends the right message.

Use cases that hold

  • One-time code with rate limit, expiry and lockout
  • “Your technician is 20 minutes away”
  • Two-way: the customer replies YES to a slot
  • Voice: ring-out on an alarm — not as your main PBX in version one

Twilio

  • Global API for SMS + voice + WhatsApp
  • You already have a Twilio account
  • Calls are part of the product

GatewayAPI

  • Mostly Danish SMS at volume
  • Price and delivery to DK numbers
  • You do not need voice this year
Pick by geography and channel — not by logo
SMS · transaktion
Din tekniker er 20 min. væk.
leveret
Transactional SMS with delivery status back on the case.

What you build regardless of vendor

1

Sender

Approved sender id or number. Not an invented company name.

2

Send

Idempotency and retry. The same case must not get three codes.

3

Status

Webhook writes delivered / failed on the user or the case.

4

Stop

Marketing has opt-out. Transaction has a log. Do not mix them.

The message is only true once the webhook is verified

What to do now

Write whether you need voice this year, or only Danish SMS. Voice + global: Twilio. DK SMS at volume only: compare GatewayAPI on price and delivery. Tell us the mix. Package prices.

FAQ about Twilio integration

Twilio or GatewayAPI?

Global + voice: Twilio. Mostly Danish SMS at volume: start by comparing GatewayAPI on price and delivery.

Can Twilio be our switchboard?

Not as version one. Start with alarm calls or verify. A full PBX is its own project.

Where does the one-time code live?

Hashed, with expiry and lockout, on your side. Not in the SMS log in clear text longer than needed.

May we send a CPR number in an SMS?

No. Never. Point to the case in your system.

SMS and voice from your backend — one socket