Activating the API (free to set up)
There's no setup charge to activate the SMS API, but activation is still recorded as a normal service order so it's properly linked to your account.
- Create or sign in to your Silurian account and verify your mobile number.
- Add the usage plan to your cart and confirm your billing and tax details.
- Since the order total is zero, no card payment is needed at this step.
- Your API credentials are generated once invoicing and setup are complete.
One active API product per account
Each client account can only have one active (or pending, or suspended) SMS API activation at a time - if you already have one, trying to activate again just takes you back to your existing order instead of creating a duplicate.
What this API is for
It's built for transactional messages: alerts, verification codes and operational updates your customer has actually requested. Before production use, Silurian reviews your sender identity, message content and destination patterns - this API isn't intended for unsolicited marketing messages, which need different infrastructure and consent handling.
How sending works: estimate, then send
Request an estimate first to validate your message and destination before committing to send it. Once you submit for real, your message is accepted into a queue and you get back a stable reference ID straight away - note that this initial HTTP response confirms your message was accepted, not that it has been delivered yet.
Tracking delivery with callbacks
Set up a callback endpoint to receive delivery-status updates as they happen. Your endpoint should verify that incoming callback requests are genuinely from Silurian, handle receiving the same event twice without causing a problem, and remember that final delivery outcomes ultimately depend on the destination mobile network, which is outside anyone's direct control.
Keeping your API credentials secure
Use a separate, individually revocable API token for each integration, and keep it stored on your server - never in code that runs in a user's browser. You can optionally restrict a token to specific source IP addresses to narrow where it can be used from.
How pricing works
Prices are public, quoted per SMS part, excluding VAT. Your estimate reflects the real cost for that specific message - destination country, character encoding, how many parts a long message splits into, which route is used and any sender-ID requirements - so you know the exact cost before you commit to sending.
