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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 0.3230 CHF
ALAlbania 0.1034 CHF
DZAlgeria 0.2630 CHF
ASAmerican Samoa 0.1104 CHF
ADAndorra 0.0783 CHF
AOAngola 0.0733 CHF
AIAnguilla 0.1522 CHF
AGAntigua & Barbuda 0.2085 CHF
ARArgentina 0.0851 CHF
AMArmenia 0.1996 CHF
AWAruba 0.1240 CHF
AUAustralia 0.0285 CHF
ATAustria 0.0488 CHF
AZAzerbaijan 0.2920 CHF
BSBahamas 0.0687 CHF
BHBahrain 0.0395 CHF
BDBangladesh 0.4316 CHF
BBBarbados 0.2290 CHF
BYBelarus 0.1656 CHF
BEBelgium 0.0761 CHF
BZBelize 0.1955 CHF
BJBenin 0.2085 CHF
BMBermuda 0.2290 CHF
BTBhutan 0.2936 CHF
BOBolivia 0.1945 CHF
BABosnia & Herzegovina 0.1325 CHF
BWBotswana 0.1233 CHF
BRBrazil 0.0236 CHF
IOBritish Indian Ocean Territory 0.1071 CHF
VGBritish Virgin Islands 0.2290 CHF
BNBrunei 0.0529 CHF
BGBulgaria 0.1292 CHF
BFBurkina Faso 0.1719 CHF
BIBurundi 0.3720 CHF
KHCambodia 0.2818 CHF
CMCameroon 0.2311 CHF
CACanada 0.0197 CHF
CVCape Verde 0.1790 CHF
KYCayman Islands 0.2114 CHF
CFCentral African Republic 0.0817 CHF
TDChad 0.2730 CHF
CLChile 0.0384 CHF
CNChina 0.0224 CHF
COColombia 0.0177 CHF
KMComoros 0.2987 CHF
CGCongo - Brazzaville 0.1832 CHF
CDCongo - Kinshasa 0.2593 CHF
CKCook Islands 0.1064 CHF
CRCosta Rica 0.0258 CHF
HRCroatia 0.1217 CHF
CUCuba 0.0769 CHF
ANCuraçao 0.1127 CHF
CWCuraçao 0.2583 CHF
CYCyprus 0.0910 CHF
CZCzechia 0.0465 CHF
CICôte d’Ivoire 0.2395 CHF
DKDenmark 0.0433 CHF
DJDjibouti 0.1099 CHF
DMDominica 0.1775 CHF
DODominican Republic 0.1133 CHF
ECEcuador 0.2452 CHF
EGEgypt 0.2621 CHF
SVEl Salvador 0.1071 CHF
GQEquatorial Guinea 0.1691 CHF
EREritrea 0.0873 CHF
EEEstonia 0.0441 CHF
SZEswatini 0.1437 CHF
ETEthiopia 0.2583 CHF
FKFalkland Islands 0.0614 CHF
FOFaroe Islands 0.0449 CHF
FJFiji 0.1586 CHF
FIFinland 0.0395 CHF
FRFrance 0.0464 CHF
GFFrench Guiana 0.0504 CHF
PFFrench Polynesia 0.0756 CHF
GAGabon 0.2525 CHF
GMGambia 0.1468 CHF
GEGeorgia 0.1133 CHF
DEGermany 0.0818 CHF
GHGhana 0.2057 CHF
GIGibraltar 0.0599 CHF
GRGreece 0.0410 CHF
GLGreenland 0.0106 CHF
GDGrenada 0.2114 CHF
GPGuadeloupe 0.1043 CHF
GUGuam 0.1155 CHF
GTGuatemala 0.1832 CHF
GNGuinea 0.2255 CHF
GWGuinea-Bissau 0.2085 CHF
GYGuyana 0.2255 CHF
HTHaiti 0.2290 CHF
HNHonduras 0.1240 CHF
HKHong Kong SAR China 0.0527 CHF
HUHungary 0.0611 CHF
ISIceland 0.0593 CHF
INIndia 0.0700 CHF
IDIndonesia 0.3786 CHF
IRIran 0.3213 CHF
IQIraq 0.3159 CHF
IEIreland 0.0395 CHF
ILIsrael 0.1879 CHF
ITItaly 0.0449 CHF
JMJamaica 0.1122 CHF
JPJapan 0.0474 CHF
JOJordan 0.2931 CHF
KZKazakhstan 0.3170 CHF
KEKenya 0.1127 CHF
KIKiribati 0.0478 CHF
XKKosovo 0.2349 CHF
KWKuwait 0.2701 CHF
KGKyrgyzstan 0.2413 CHF
LALaos 0.1184 CHF
LVLatvia 0.0470 CHF
LBLebanon 0.0451 CHF
LSLesotho 0.2226 CHF
LRLiberia 0.1691 CHF
LYLibya 0.2995 CHF
LILiechtenstein 0.0375 CHF
LTLithuania 0.0381 CHF
LULuxembourg 0.0958 CHF
MOMacao SAR China 0.0413 CHF
MGMadagascar 0.3669 CHF
MWMalawi 0.2466 CHF
MYMalaysia 0.1409 CHF
MVMaldives 0.0592 CHF
MLMali 0.2001 CHF
MTMalta 0.0515 CHF
MHMarshall Islands 0.0529 CHF
MQMartinique 0.0470 CHF
MRMauritania 0.2142 CHF
MUMauritius 0.1451 CHF
MXMexico 0.0676 CHF
FMMicronesia 0.0693 CHF
MDMoldova 0.1252 CHF
MCMonaco 0.1234 CHF
MNMongolia 0.2760 CHF
MEMontenegro 0.1351 CHF
MSMontserrat 0.1184 CHF
MAMorocco 0.0676 CHF
MZMozambique 0.1184 CHF
MMMyanmar (Burma) 0.3465 CHF
NANamibia 0.0398 CHF
NRNauru 0.1586 CHF
NPNepal 0.2311 CHF
NLNetherlands 0.0717 CHF
NCNew Caledonia 0.1114 CHF
NZNew Zealand 0.0395 CHF
NINicaragua 0.1099 CHF
NENiger 0.2643 CHF
NGNigeria 0.3156 CHF
NUNiue 0.1527 CHF
KPNorth Korea 0.0788 CHF
MKNorth Macedonia 0.0828 CHF
NONorway 0.0338 CHF
OMOman 0.1644 CHF
PKPakistan 0.3382 CHF
PWPalau 0.1076 CHF
PSPalestinian Territories 0.2777 CHF
PAPanama 0.1381 CHF
PGPapua New Guinea 0.1821 CHF
PYParaguay 0.0789 CHF
PEPeru 0.1184 CHF
PHPhilippines 0.1991 CHF
PLPoland 0.0235 CHF
PTPortugal 0.0247 CHF
PRPuerto Rico 0.0982 CHF
QAQatar 0.0986 CHF
RORomania 0.0435 CHF
RURussia 0.3793 CHF
RWRwanda 0.2612 CHF
RERéunion 0.0592 CHF
WSSamoa 0.1325 CHF
SMSan Marino 0.0526 CHF
SASaudi Arabia 0.1804 CHF
SNSenegal 0.2226 CHF
RSSerbia 0.1832 CHF
SCSeychelles 0.1015 CHF
SLSierra Leone 0.2198 CHF
SGSingapore 0.0433 CHF
SXSint Maarten 0.0879 CHF
SKSlovakia 0.0477 CHF
SISlovenia 0.1468 CHF
SBSolomon Islands 0.0789 CHF
SOSomalia 0.2001 CHF
ZASouth Africa 0.0451 CHF
KRSouth Korea 0.0188 CHF
SSSouth Sudan 0.2466 CHF
ESSpain 0.0348 CHF
LKSri Lanka 0.3517 CHF
SHSt. Helena 0.0881 CHF
KNSt. Kitts & Nevis 0.2290 CHF
LCSt. Lucia 0.2226 CHF
PMSt. Pierre & Miquelon 0.1127 CHF
VCSt. Vincent & Grenadines 0.1775 CHF
SDSudan 0.2877 CHF
SRSuriname 0.2057 CHF
SESweden 0.0456 CHF
CHSwitzerland 0.0558 CHF
SYSyria 0.2766 CHF
STSão Tomé & Príncipe 0.0225 CHF
TWTaiwan 0.0705 CHF
TJTajikistan 0.3389 CHF
TZTanzania 0.2525 CHF
THThailand 0.0164 CHF
TLTimor-Leste 0.1381 CHF
TGTogo 0.1635 CHF
TKTokelau 0.0235 CHF
TOTonga 0.1586 CHF
TTTrinidad & Tobago 0.2226 CHF
TNTunisia 0.2705 CHF
TMTurkmenistan 0.2055 CHF
TCTurks & Caicos Islands 0.1497 CHF
TVTuvalu 0.1468 CHF
TRTürkiye 0.0071 CHF
VIU.S. Virgin Islands 0.0347 CHF
UGUganda 0.2654 CHF
UAUkraine 0.1644 CHF
AEUnited Arab Emirates 0.0858 CHF
GBUnited Kingdom 0.0377 CHF
USUnited States 0.0197 CHF
ZZUnknown Region 0.0775 CHF
UYUruguay 0.0999 CHF
UZUzbekistan 0.3640 CHF
VUVanuatu 0.1550 CHF
VEVenezuela 0.1240 CHF
VNVietnam 0.2085 CHF
WFWallis & Futuna 0.0696 CHF
YEYemen 0.1620 CHF
ZMZambia 0.2460 CHF
ZWZimbabwe 0.1709 CHF