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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 0.3190 CHF
ALAlbania 0.1022 CHF
DZAlgeria 0.2598 CHF
ASAmerican Samoa 0.1090 CHF
ADAndorra 0.0773 CHF
AOAngola 0.0724 CHF
AIAnguilla 0.1503 CHF
AGAntigua & Barbuda 0.2060 CHF
ARArgentina 0.0841 CHF
AMArmenia 0.1972 CHF
AWAruba 0.1225 CHF
AUAustralia 0.0281 CHF
ATAustria 0.0483 CHF
AZAzerbaijan 0.2884 CHF
BSBahamas 0.0678 CHF
BHBahrain 0.0390 CHF
BDBangladesh 0.4263 CHF
BBBarbados 0.2262 CHF
BYBelarus 0.1636 CHF
BEBelgium 0.0752 CHF
BZBelize 0.1931 CHF
BJBenin 0.2059 CHF
BMBermuda 0.2262 CHF
BTBhutan 0.2900 CHF
BOBolivia 0.1921 CHF
BABosnia & Herzegovina 0.1308 CHF
BWBotswana 0.1218 CHF
BRBrazil 0.0233 CHF
IOBritish Indian Ocean Territory 0.1058 CHF
VGBritish Virgin Islands 0.2262 CHF
BNBrunei 0.0522 CHF
BGBulgaria 0.1276 CHF
BFBurkina Faso 0.1698 CHF
BIBurundi 0.3674 CHF
KHCambodia 0.2784 CHF
CMCameroon 0.2283 CHF
CACanada 0.0195 CHF
CVCape Verde 0.1769 CHF
KYCayman Islands 0.2088 CHF
CFCentral African Republic 0.0807 CHF
TDChad 0.2696 CHF
CLChile 0.0380 CHF
CNChina 0.0221 CHF
COColombia 0.0174 CHF
KMComoros 0.2951 CHF
CGCongo - Brazzaville 0.1809 CHF
CDCongo - Kinshasa 0.2561 CHF
CKCook Islands 0.1051 CHF
CRCosta Rica 0.0255 CHF
HRCroatia 0.1202 CHF
CUCuba 0.0760 CHF
ANCuraçao 0.1113 CHF
CWCuraçao 0.2552 CHF
CYCyprus 0.0899 CHF
CZCzechia 0.0459 CHF
CICôte d’Ivoire 0.2366 CHF
DKDenmark 0.0428 CHF
DJDjibouti 0.1086 CHF
DMDominica 0.1754 CHF
DODominican Republic 0.1119 CHF
ECEcuador 0.2422 CHF
EGEgypt 0.2589 CHF
SVEl Salvador 0.1058 CHF
GQEquatorial Guinea 0.1670 CHF
EREritrea 0.0862 CHF
EEEstonia 0.0435 CHF
SZEswatini 0.1420 CHF
ETEthiopia 0.2552 CHF
FKFalkland Islands 0.0607 CHF
FOFaroe Islands 0.0444 CHF
FJFiji 0.1566 CHF
FIFinland 0.0390 CHF
FRFrance 0.0458 CHF
GFFrench Guiana 0.0497 CHF
PFFrench Polynesia 0.0747 CHF
GAGabon 0.2494 CHF
GMGambia 0.1450 CHF
GEGeorgia 0.1119 CHF
DEGermany 0.0808 CHF
GHGhana 0.2032 CHF
GIGibraltar 0.0592 CHF
GRGreece 0.0405 CHF
GLGreenland 0.0105 CHF
GDGrenada 0.2088 CHF
GPGuadeloupe 0.1030 CHF
GUGuam 0.1141 CHF
GTGuatemala 0.1809 CHF
GNGuinea 0.2227 CHF
GWGuinea-Bissau 0.2060 CHF
GYGuyana 0.2227 CHF
HTHaiti 0.2262 CHF
HNHonduras 0.1225 CHF
HKHong Kong SAR China 0.0521 CHF
HUHungary 0.0603 CHF
ISIceland 0.0586 CHF
INIndia 0.0691 CHF
IDIndonesia 0.3739 CHF
IRIran 0.3173 CHF
IQIraq 0.3121 CHF
IEIreland 0.0390 CHF
ILIsrael 0.1856 CHF
ITItaly 0.0444 CHF
JMJamaica 0.1108 CHF
JPJapan 0.0469 CHF
JOJordan 0.2895 CHF
KZKazakhstan 0.3132 CHF
KEKenya 0.1113 CHF
KIKiribati 0.0472 CHF
XKKosovo 0.2320 CHF
KWKuwait 0.2668 CHF
KGKyrgyzstan 0.2384 CHF
LALaos 0.1169 CHF
LVLatvia 0.0464 CHF
LBLebanon 0.0445 CHF
LSLesotho 0.2199 CHF
LRLiberia 0.1670 CHF
LYLibya 0.2958 CHF
LILiechtenstein 0.0370 CHF
LTLithuania 0.0377 CHF
LULuxembourg 0.0946 CHF
MOMacao SAR China 0.0408 CHF
MGMadagascar 0.3624 CHF
MWMalawi 0.2436 CHF
MYMalaysia 0.1392 CHF
MVMaldives 0.0585 CHF
MLMali 0.1976 CHF
MTMalta 0.0508 CHF
MHMarshall Islands 0.0522 CHF
MQMartinique 0.0464 CHF
MRMauritania 0.2116 CHF
MUMauritius 0.1434 CHF
MXMexico 0.0668 CHF
FMMicronesia 0.0685 CHF
MDMoldova 0.1237 CHF
MCMonaco 0.1219 CHF
MNMongolia 0.2726 CHF
MEMontenegro 0.1334 CHF
MSMontserrat 0.1169 CHF
MAMorocco 0.0668 CHF
MZMozambique 0.1169 CHF
MMMyanmar (Burma) 0.3422 CHF
NANamibia 0.0393 CHF
NRNauru 0.1566 CHF
NPNepal 0.2283 CHF
NLNetherlands 0.0708 CHF
NCNew Caledonia 0.1100 CHF
NZNew Zealand 0.0390 CHF
NINicaragua 0.1086 CHF
NENiger 0.2610 CHF
NGNigeria 0.3118 CHF
NUNiue 0.1508 CHF
KPNorth Korea 0.0779 CHF
MKNorth Macedonia 0.0817 CHF
NONorway 0.0334 CHF
OMOman 0.1624 CHF
PKPakistan 0.3340 CHF
PWPalau 0.1062 CHF
PSPalestinian Territories 0.2743 CHF
PAPanama 0.1364 CHF
PGPapua New Guinea 0.1798 CHF
PYParaguay 0.0779 CHF
PEPeru 0.1169 CHF
PHPhilippines 0.1966 CHF
PLPoland 0.0232 CHF
PTPortugal 0.0244 CHF
PRPuerto Rico 0.0970 CHF
QAQatar 0.0974 CHF
RORomania 0.0430 CHF
RURussia 0.3747 CHF
RWRwanda 0.2580 CHF
RERéunion 0.0585 CHF
WSSamoa 0.1308 CHF
SMSan Marino 0.0520 CHF
SASaudi Arabia 0.1782 CHF
SNSenegal 0.2199 CHF
RSSerbia 0.1809 CHF
SCSeychelles 0.1002 CHF
SLSierra Leone 0.2171 CHF
SGSingapore 0.0428 CHF
SXSint Maarten 0.0869 CHF
SKSlovakia 0.0471 CHF
SISlovenia 0.1450 CHF
SBSolomon Islands 0.0779 CHF
SOSomalia 0.1976 CHF
ZASouth Africa 0.0445 CHF
KRSouth Korea 0.0186 CHF
SSSouth Sudan 0.2436 CHF
ESSpain 0.0343 CHF
LKSri Lanka 0.3474 CHF
SHSt. Helena 0.0870 CHF
KNSt. Kitts & Nevis 0.2262 CHF
LCSt. Lucia 0.2199 CHF
PMSt. Pierre & Miquelon 0.1113 CHF
VCSt. Vincent & Grenadines 0.1754 CHF
SDSudan 0.2842 CHF
SRSuriname 0.2032 CHF
SESweden 0.0450 CHF
CHSwitzerland 0.0551 CHF
SYSyria 0.2732 CHF
STSão Tomé & Príncipe 0.0223 CHF
TWTaiwan 0.0696 CHF
TJTajikistan 0.3348 CHF
TZTanzania 0.2494 CHF
THThailand 0.0162 CHF
TLTimor-Leste 0.1364 CHF
TGTogo 0.1615 CHF
TKTokelau 0.0232 CHF
TOTonga 0.1566 CHF
TTTrinidad & Tobago 0.2199 CHF
TNTunisia 0.2672 CHF
TMTurkmenistan 0.2030 CHF
TCTurks & Caicos Islands 0.1479 CHF
TVTuvalu 0.1450 CHF
TRTürkiye 0.0071 CHF
VIU.S. Virgin Islands 0.0342 CHF
UGUganda 0.2621 CHF
UAUkraine 0.1624 CHF
AEUnited Arab Emirates 0.0847 CHF
GBUnited Kingdom 0.0372 CHF
USUnited States 0.0195 CHF
ZZUnknown Region 0.0766 CHF
UYUruguay 0.0986 CHF
UZUzbekistan 0.3596 CHF
VUVanuatu 0.1531 CHF
VEVenezuela 0.1225 CHF
VNVietnam 0.2059 CHF
WFWallis & Futuna 0.0688 CHF
YEYemen 0.1601 CHF
ZMZambia 0.2430 CHF
ZWZimbabwe 0.1688 CHF