How to migrate from Smstools to Vonage

Smstools is a Belgian business-messaging platform offering an SMS gateway, WhatsApp Business, voice messages and email-to-SMS with EU-only hosting. Vonage is a broader communications-API provider (part of Ericsson) covering SMS, MMS, RCS, WhatsApp, Viber, Facebook Messenger and voice across multiple regions. On the messaging.dev Score, Smstools rates 56/100 and Vonage 89/100 — this guide walks through what actually changes at the API level when you move from one to the other.

What you gain and what you lose

Channels. Moving to Vonage adds four channels you do not have on Smstools: MMS, RCS, Viber and Facebook Messenger. You keep SMS, WhatsApp and voice, which both platforms support. You lose no channel in the move — neither provider offers Telegram, Apple Messages for Business or a native email channel.

Compliance. Both are GDPR-aligned. Vonage additionally carries ISO 27001, SOC 2 and HIPAA, none of which Smstools lists — relevant if you have procurement or regulated-industry requirements.

Data residency. Smstools hosts in the EU only, with no region choice. Vonage offers EU and US servers plus APAC and Australia, and lets you choose your data-residency region.

Pricing and credit. Both use pay-as-you-go per message with volume discounts and no subscription. Smstools quotes from €0.025 per SMS to the USA; Vonage quotes approximately $0.0072 per US SMS segment plus carrier fees, so compare on your own routes rather than headline rates. Smstools grants a free test credit on sign-up; Vonage grants €2 trial credit.

SDKs, docs, sandbox. Both rate high on docs quality and both offer a sandbox. Shared SDKs are PHP, Node.js, Python and Ruby. Vonage adds Java, C# and Kotlin but does not ship the PowerShell SDK that Smstools offers. Note also that Smstools exposes both REST and an SMTP (email-to-SMS) interface, whereas Vonage is REST-only.

How the request format differs

Smstools quickstart:

curl -X POST "https://api.smsgatewayapi.com/v1/message/send" \
  -H "X-Client-Id: YOUR_CLIENT_ID" \
  -H "X-Client-Secret: YOUR_CLIENT_SECRET" \
  -H "Content-Type: application/json" \
  -d '{"message": "Hello World", "to": "11231231234", "sender": "YourName"}'

Vonage quickstart:

curl -X POST 'https://rest.nexmo.com/sms/json' \
  -d 'api_key=YOUR_API_KEY' \
  -d 'api_secret=YOUR_API_SECRET' \
  -d 'from=Vonage' \
  -d 'to=15551234567' \
  -d 'text=Hello from Vonage'

Three things change:

• Endpoint. You move from https://api.smsgatewayapi.com/v1/message/send to https://rest.nexmo.com/sms/json (Vonage’s legacy SMS API) or https://api.nexmo.com/v1/messages (the multichannel Messages API).
• Authentication. Smstools authenticates with an API key and secret sent as X-Client-Id and X-Client-Secret headers. Vonage’s SMS API takes api_key and api_secret as body parameters instead of headers; the Messages API uses JWT auth. You are moving credentials out of headers and into the request body (or into a signed token).
• Payload. Smstools sends a JSON body; Vonage’s SMS API sends form-encoded fields. Field mapping: the message body message becomes text, the sender sender becomes from, and the recipient to keeps the same name (just supply the destination in Vonage’s expected format).

Migration checklist

1. Create a Vonage account and generate an API key and secret in the dashboard. For multichannel sending, also provision the JWT credentials the Messages API needs.
2. Map each request field: message → text, sender → from, to → to.
3. Re-point your sending code to the new endpoint and switch from JSON headers auth to Vonage’s form-encoded key/secret (or JWT for the Messages API).
4. Re-test in Vonage’s sandbox — it offers one — before sending live traffic.
5. Update your delivery-receipt and inbound webhooks to Vonage’s callback format and register the new callback URLs.
6. Run both providers in parallel, comparing delivery results on real routes.
7. Cut over once parity holds, then decommission the Smstools integration.

For a from-scratch walkthrough of the target, see how to start with Vonage, and for a full field-by-field breakdown see the Smstools vs Vonage comparison.

Watch out for

• Lower uptime SLA. Vonage publishes a 99.95% SLA versus Smstools’ 99.99%.
• No SMTP path. Smstools supports an SMTP email-to-SMS interface; Vonage is REST-only, so any email-to-SMS flow needs rebuilding.
• Dropped SDK. There is no official PowerShell SDK on Vonage.
• Auth complexity. The multichannel Messages API requires JWT auth, which is more involved than static key/secret headers.
• Carrier fees. Vonage’s US SMS price excludes carrier fees, so your effective per-message cost can be higher than the quoted rate.