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SMS Developer API

Transactional messaging, built into your application.

Send alerts, verification messages and customer updates through a documented API designed for real operational workflows.

Built for developers

One clear API for the messages your product needs to send.

Start with a direct integration, then add controls and delivery feedback as the workflow becomes more important.

01

Send with confidence

Submit outbound SMS through a documented API with recipient and message validation before it enters the delivery queue.

02

Estimate before sending

Check the message and destination before committing usage, so your application can make deliberate decisions.

03

Follow asynchronous status

Use callbacks for delivery events and, where needed, HLR lookup results in the systems that need them.

04

Control access

Use API tokens and optional IP restrictions to keep a production integration scoped to the right system.

From request to result

A small API surface with a clear operational lifecycle.

Your application remains in control: validate the destination, estimate usage, submit once and consume delivery events asynchronously.

01 / Authorise

One token per integration.

Keep production systems isolated with revocable credentials and optional source-IP restrictions.

  • Server-side API tokens
  • Optional IP allowlists
  • No credentials in browser code
02 / Estimate

Know the message before sending.

Use the estimate operation to validate recipient and message characteristics before committing the request.

  • Destination validation
  • Message-part awareness
  • Explicit application decision
03 / Queue

Submit without blocking your product.

Accepted messages enter an asynchronous delivery workflow and return a reference your application can retain.

  • Queued processing
  • Stable message reference
  • Transactional workloads
04 / Observe

Bring status back to your system.

Delivery callbacks let your application update its own workflow without repeatedly polling for every message.

  • Webhook callbacks
  • Delivery-state events
  • Audit-friendly processing
05 / Verify

Support identity workflows.

Use SMS for account creation, requested notifications and two-step login challenges with your own expiry and retry policy.

  • Verification codes
  • Operational notifications
  • No unsolicited marketing
06 / Scale

Pay for actual messaging.

The service is usage-based. Destination, route and sender requirements are confirmed before production traffic is enabled.

  • Country-aware routing
  • Sender review where required
  • Transparent usage records

Manage credentials, allowed sources, usage and delivery activity securely from your Silurian workspace.

Good to know. Delivery confirmation and sender behaviour depend on destination country, network and approved sending route. We will help define the appropriate setup before production use.

Developer experience

Integrate SMS into your applications easily.

Send the same authenticated JSON request from your preferred server-side stack. Keep the API token outside browser code and use the estimate operation before sending when price or message length matters.

Open the interactive API reference
curl --request POST 'https://api.silurian.net/sms/v2/send' \
  --user 'YOUR_API_TOKEN:' \
  --header 'Content-Type: application/json' \
  --data '{
    "sender": "YOURBRAND",
    "message": "Your verification code is 123456.",
    "recipients": [{"msisdn": "+34XXXXXXXXX"}]
  }'
Examples use HTTP Basic authentication with the API token as username. The interactive reference also documents header, query-token and short-lived Bearer authentication.

Destination pricing

Know the destination price before your application sends.

Prices below are the current public Silurian rate per SMS part, before VAT. The API estimate operation remains authoritative because message length, destination, route and sender requirements are checked for each request.

DestinationPrice per SMS part
AFAfghanistan 2.5699 DKK
ALAlbania 0.8230 DKK
DZAlgeria 2.0930 DKK
ASAmerican Samoa 0.8783 DKK
ADAndorra 0.6227 DKK
AOAngola 0.5830 DKK
AIAnguilla 1.2109 DKK
AGAntigua & Barbuda 1.6594 DKK
ARArgentina 0.6772 DKK
AMArmenia 1.5884 DKK
AWAruba 0.9867 DKK
AUAustralia 0.2265 DKK
ATAustria 0.3887 DKK
AZAzerbaijan 2.3232 DKK
BSBahamas 0.5464 DKK
BHBahrain 0.3139 DKK
BDBangladesh 3.4340 DKK
BBBarbados 1.8224 DKK
BYBelarus 1.3178 DKK
BEBelgium 0.6055 DKK
BZBelize 1.5555 DKK
BJBenin 1.6587 DKK
BMBermuda 1.8224 DKK
BTBhutan 2.3359 DKK
BOBolivia 1.5473 DKK
BABosnia & Herzegovina 1.0540 DKK
BWBotswana 0.9815 DKK
BRBrazil 0.1876 DKK
IOBritish Indian Ocean Territory 0.8521 DKK
VGBritish Virgin Islands 1.8224 DKK
BNBrunei 0.4208 DKK
BGBulgaria 1.0278 DKK
BFBurkina Faso 1.3679 DKK
BIBurundi 2.9601 DKK
KHCambodia 2.2425 DKK
CMCameroon 1.8388 DKK
CACanada 0.1570 DKK
CVCape Verde 1.4247 DKK
KYCayman Islands 1.6819 DKK
CFCentral African Republic 0.6503 DKK
TDChad 2.1722 DKK
CLChile 0.3057 DKK
CNChina 0.1779 DKK
COColombia 0.1405 DKK
KMComoros 2.3770 DKK
CGCongo - Brazzaville 1.4576 DKK
CDCongo - Kinshasa 2.0631 DKK
CKCook Islands 0.8469 DKK
CRCosta Rica 0.2056 DKK
HRCroatia 0.9680 DKK
CUCuba 0.6122 DKK
ANCuraçao 0.8970 DKK
CWCuraçao 2.0556 DKK
CYCyprus 0.7243 DKK
CZCzechia 0.3700 DKK
CICôte d’Ivoire 1.9061 DKK
DKDenmark 0.3446 DKK
DJDjibouti 0.8746 DKK
DMDominica 1.4128 DKK
DODominican Republic 0.9015 DKK
ECEcuador 1.9509 DKK
EGEgypt 2.0855 DKK
SVEl Salvador 0.8521 DKK
GQEquatorial Guinea 1.3455 DKK
EREritrea 0.6944 DKK
EEEstonia 0.3506 DKK
SZEswatini 1.1437 DKK
ETEthiopia 2.0556 DKK
FKFalkland Islands 0.4889 DKK
FOFaroe Islands 0.3573 DKK
FJFiji 1.2618 DKK
FIFinland 0.3139 DKK
FRFrance 0.3693 DKK
GFFrench Guiana 0.4007 DKK
PFFrench Polynesia 0.6017 DKK
GAGabon 2.0093 DKK
GMGambia 1.1683 DKK
GEGeorgia 0.9015 DKK
DEGermany 0.6511 DKK
GHGhana 1.6370 DKK
GIGibraltar 0.4769 DKK
GRGreece 0.3259 DKK
GLGreenland 0.0845 DKK
GDGrenada 1.6819 DKK
GPGuadeloupe 0.8297 DKK
GUGuam 0.9194 DKK
GTGuatemala 1.4576 DKK
GNGuinea 1.7940 DKK
GWGuinea-Bissau 1.6594 DKK
GYGuyana 1.7940 DKK
HTHaiti 1.8224 DKK
HNHonduras 0.9867 DKK
HKHong Kong SAR China 0.4193 DKK
HUHungary 0.4859 DKK
ISIceland 0.4717 DKK
INIndia 0.5569 DKK
IDIndonesia 3.0124 DKK
IRIran 2.5564 DKK
IQIraq 2.5138 DKK
IEIreland 0.3139 DKK
ILIsrael 1.4950 DKK
ITItaly 0.3573 DKK
JMJamaica 0.8925 DKK
JPJapan 0.3775 DKK
JOJordan 2.3322 DKK
KZKazakhstan 2.5228 DKK
KEKenya 0.8970 DKK
KIKiribati 0.3805 DKK
XKKosovo 1.8687 DKK
KWKuwait 2.1490 DKK
KGKyrgyzstan 1.9203 DKK
LALaos 0.9418 DKK
LVLatvia 0.3737 DKK
LBLebanon 0.3588 DKK
LSLesotho 1.7716 DKK
LRLiberia 1.3455 DKK
LYLibya 2.3830 DKK
LILiechtenstein 0.2982 DKK
LTLithuania 0.3035 DKK
LULuxembourg 0.7624 DKK
MOMacao SAR China 0.3289 DKK
MGMadagascar 2.9197 DKK
MWMalawi 1.9622 DKK
MYMalaysia 1.1212 DKK
MVMaldives 0.4709 DKK
MLMali 1.5922 DKK
MTMalta 0.4096 DKK
MHMarshall Islands 0.4208 DKK
MQMartinique 0.3737 DKK
MRMauritania 1.7043 DKK
MUMauritius 1.1549 DKK
MXMexico 0.5382 DKK
FMMicronesia 0.5516 DKK
MDMoldova 0.9964 DKK
MCMonaco 0.9822 DKK
MNMongolia 2.1961 DKK
MEMontenegro 1.0749 DKK
MSMontserrat 0.9418 DKK
MAMorocco 0.5382 DKK
MZMozambique 0.9418 DKK
MMMyanmar (Burma) 2.7567 DKK
NANamibia 0.3169 DKK
NRNauru 1.2618 DKK
NPNepal 1.8388 DKK
NLNetherlands 0.5703 DKK
NCNew Caledonia 0.8865 DKK
NZNew Zealand 0.3139 DKK
NINicaragua 0.8746 DKK
NENiger 2.1027 DKK
NGNigeria 2.5116 DKK
NUNiue 1.2147 DKK
KPNorth Korea 0.6271 DKK
MKNorth Macedonia 0.6585 DKK
NONorway 0.2691 DKK
OMOman 1.3081 DKK
PKPakistan 2.6910 DKK
PWPalau 0.8559 DKK
PSPalestinian Territories 2.2096 DKK
PAPanama 1.0988 DKK
PGPapua New Guinea 1.4486 DKK
PYParaguay 0.6279 DKK
PEPeru 0.9418 DKK
PHPhilippines 1.5839 DKK
PLPoland 0.1869 DKK
PTPortugal 0.1966 DKK
PRPuerto Rico 0.7811 DKK
QAQatar 0.7849 DKK
RORomania 0.3461 DKK
RURussia 3.0184 DKK
RWRwanda 2.0788 DKK
RERéunion 0.4709 DKK
WSSamoa 1.0540 DKK
SMSan Marino 0.4186 DKK
SASaudi Arabia 1.4352 DKK
SNSenegal 1.7716 DKK
RSSerbia 1.4576 DKK
SCSeychelles 0.8073 DKK
SLSierra Leone 1.7491 DKK
SGSingapore 0.3446 DKK
SXSint Maarten 0.6997 DKK
SKSlovakia 0.3797 DKK
SISlovenia 1.1683 DKK
SBSolomon Islands 0.6279 DKK
SOSomalia 1.5922 DKK
ZASouth Africa 0.3588 DKK
KRSouth Korea 0.1495 DKK
SSSouth Sudan 1.9622 DKK
ESSpain 0.2766 DKK
LKSri Lanka 2.7986 DKK
SHSt. Helena 0.7011 DKK
KNSt. Kitts & Nevis 1.8224 DKK
LCSt. Lucia 1.7716 DKK
PMSt. Pierre & Miquelon 0.8970 DKK
VCSt. Vincent & Grenadines 1.4128 DKK
SDSudan 2.2896 DKK
SRSuriname 1.6370 DKK
SESweden 0.3625 DKK
CHSwitzerland 0.4440 DKK
SYSyria 2.2006 DKK
STSão Tomé & Príncipe 0.1794 DKK
TWTaiwan 0.5606 DKK
TJTajikistan 2.6969 DKK
TZTanzania 2.0093 DKK
THThailand 0.1308 DKK
TLTimor-Leste 1.0988 DKK
TGTogo 1.3006 DKK
TKTokelau 0.1869 DKK
TOTonga 1.2618 DKK
TTTrinidad & Tobago 1.7716 DKK
TNTunisia 2.1528 DKK
TMTurkmenistan 1.6355 DKK
TCTurks & Caicos Islands 1.1915 DKK
TVTuvalu 1.1683 DKK
TRTürkiye 0.0568 DKK
VIU.S. Virgin Islands 0.2758 DKK
UGUganda 2.1117 DKK
UAUkraine 1.3081 DKK
AEUnited Arab Emirates 0.6825 DKK
GBUnited Kingdom 0.2997 DKK
USUnited States 0.1570 DKK
ZZUnknown Region 0.6167 DKK
UYUruguay 0.7946 DKK
UZUzbekistan 2.8965 DKK
VUVanuatu 1.2334 DKK
VEVenezuela 0.9867 DKK
VNVietnam 1.6587 DKK
WFWallis & Futuna 0.5539 DKK
YEYemen 1.2894 DKK
ZMZambia 1.9577 DKK
ZWZimbabwe 1.3597 DKK