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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 0.2879 GBP
ALAlbania 0.0922 GBP
DZAlgeria 0.2344 GBP
ASAmerican Samoa 0.0984 GBP
ADAndorra 0.0697 GBP
AOAngola 0.0653 GBP
AIAnguilla 0.1356 GBP
AGAntigua & Barbuda 0.1859 GBP
ARArgentina 0.0759 GBP
AMArmenia 0.2041 GBP
AWAruba 0.1105 GBP
AUAustralia 0.0254 GBP
ATAustria 0.0435 GBP
AZAzerbaijan 0.2601 GBP
BSBahamas 0.0754 GBP
BHBahrain 0.0352 GBP
BDBangladesh 0.3846 GBP
BBBarbados 0.2185 GBP
BYBelarus 0.1476 GBP
BEBelgium 0.0678 GBP
BZBelize 0.1742 GBP
BJBenin 0.2261 GBP
BMBermuda 0.2198 GBP
BTBhutan 0.3140 GBP
BOBolivia 0.1733 GBP
BABosnia & Herzegovina 0.1181 GBP
BWBotswana 0.1206 GBP
BRBrazil 0.0210 GBP
IOBritish Indian Ocean Territory 0.0954 GBP
VGBritish Virgin Islands 0.2198 GBP
BNBrunei 0.0471 GBP
BGBulgaria 0.1204 GBP
BFBurkina Faso 0.1532 GBP
BIBurundi 0.3316 GBP
KHCambodia 0.2512 GBP
CMCameroon 0.2060 GBP
CACanada 0.0176 GBP
CVCape Verde 0.1596 GBP
BQCaribbean Netherlands 0.2512 GBP
KYCayman Islands 0.1884 GBP
CFCentral African Republic 0.0728 GBP
TDChad 0.2433 GBP
CLChile 0.0342 GBP
CNChina 0.0199 GBP
COColombia 0.0157 GBP
KMComoros 0.2663 GBP
CGCongo - Brazzaville 0.1633 GBP
CDCongo - Kinshasa 0.2311 GBP
CKCook Islands 0.0949 GBP
CRCosta Rica 0.0262 GBP
HRCroatia 0.1084 GBP
CUCuba 0.0686 GBP
ANCuraçao 0.1005 GBP
CWCuraçao 0.2407 GBP
CYCyprus 0.0811 GBP
CZCzechia 0.0414 GBP
CICôte d’Ivoire 0.2135 GBP
DKDenmark 0.0386 GBP
DJDjibouti 0.0980 GBP
DMDominica 0.1582 GBP
DODominican Republic 0.1010 GBP
ECEcuador 0.2185 GBP
EGEgypt 0.2336 GBP
SVEl Salvador 0.0954 GBP
GQEquatorial Guinea 0.1507 GBP
EREritrea 0.0778 GBP
EEEstonia 0.0393 GBP
SZEswatini 0.1281 GBP
ETEthiopia 0.2303 GBP
FKFalkland Islands 0.0548 GBP
FOFaroe Islands 0.0400 GBP
FJFiji 0.1570 GBP
FIFinland 0.0352 GBP
FRFrance 0.0448 GBP
GFFrench Guiana 0.0449 GBP
PFFrench Polynesia 0.0674 GBP
GAGabon 0.2251 GBP
GMGambia 0.1758 GBP
GEGeorgia 0.1010 GBP
DEGermany 0.0756 GBP
GHGhana 0.1834 GBP
GIGibraltar 0.0586 GBP
GRGreece 0.0365 GBP
GLGreenland 0.0095 GBP
GDGrenada 0.1884 GBP
GPGuadeloupe 0.0929 GBP
GUGuam 0.1030 GBP
GTGuatemala 0.1633 GBP
GNGuinea 0.2009 GBP
GWGuinea-Bissau 0.1859 GBP
GYGuyana 0.2114 GBP
HTHaiti 0.2041 GBP
HNHonduras 0.1105 GBP
HKHong Kong SAR China 0.0497 GBP
HUHungary 0.0544 GBP
ISIceland 0.0528 GBP
INIndia 0.0624 GBP
IDIndonesia 0.3374 GBP
IRIran 0.2863 GBP
IQIraq 0.2816 GBP
IEIreland 0.0352 GBP
ILIsrael 0.1779 GBP
ITItaly 0.0419 GBP
JMJamaica 0.1000 GBP
JPJapan 0.0423 GBP
JOJordan 0.2612 GBP
KZKazakhstan 0.2826 GBP
KEKenya 0.1005 GBP
KIKiribati 0.0426 GBP
XKKosovo 0.6280 GBP
KWKuwait 0.2617 GBP
KGKyrgyzstan 0.2151 GBP
LALaos 0.1055 GBP
LVLatvia 0.0419 GBP
LBLebanon 0.0402 GBP
LSLesotho 0.1984 GBP
LRLiberia 0.1507 GBP
LYLibya 0.2669 GBP
LILiechtenstein 0.0334 GBP
LTLithuania 0.0340 GBP
LULuxembourg 0.0854 GBP
MOMacao SAR China 0.0368 GBP
MGMadagascar 0.3270 GBP
MWMalawi 0.2198 GBP
MYMalaysia 0.1256 GBP
MVMaldives 0.0527 GBP
MLMali 0.1783 GBP
MTMalta 0.0459 GBP
MHMarshall Islands 0.0471 GBP
MQMartinique 0.0929 GBP
MRMauritania 0.1909 GBP
MUMauritius 0.1294 GBP
YTMayotte 0.0576 GBP
MXMexico 0.0603 GBP
FMMicronesia 0.0618 GBP
MDMoldova 0.1382 GBP
MCMonaco 0.1100 GBP
MNMongolia 0.2459 GBP
MEMontenegro 0.1204 GBP
MSMontserrat 0.1055 GBP
MAMorocco 0.0603 GBP
MZMozambique 0.1055 GBP
MMMyanmar (Burma) 0.3087 GBP
NANamibia 0.0578 GBP
NRNauru 0.1570 GBP
NPNepal 0.2060 GBP
NLNetherlands 0.0700 GBP
NCNew Caledonia 0.0993 GBP
NZNew Zealand 0.0352 GBP
NINicaragua 0.0980 GBP
NENiger 0.2355 GBP
NGNigeria 0.2813 GBP
NUNiue 0.1361 GBP
KPNorth Korea 0.1465 GBP
MKNorth Macedonia 0.0738 GBP
NONorway 0.0301 GBP
OMOman 0.1465 GBP
PKPakistan 0.3014 GBP
PWPalau 0.0959 GBP
PSPalestinian Territories 0.2475 GBP
PAPanama 0.1231 GBP
PGPapua New Guinea 0.1623 GBP
PYParaguay 0.0703 GBP
PEPeru 0.1055 GBP
PHPhilippines 0.1774 GBP
PLPoland 0.0209 GBP
PTPortugal 0.0251 GBP
PRPuerto Rico 0.0875 GBP
QAQatar 0.0879 GBP
RORomania 0.0388 GBP
RURussia 0.3381 GBP
RWRwanda 0.2361 GBP
RERéunion 0.0527 GBP
WSSamoa 0.1181 GBP
SMSan Marino 0.0733 GBP
SASaudi Arabia 0.1608 GBP
SNSenegal 0.1984 GBP
RSSerbia 0.1633 GBP
SCSeychelles 0.0904 GBP
SLSierra Leone 0.1959 GBP
SGSingapore 0.0386 GBP
SXSint Maarten 0.0784 GBP
SKSlovakia 0.0425 GBP
SISlovenia 0.1309 GBP
SBSolomon Islands 0.0703 GBP
SOSomalia 0.1783 GBP
ZASouth Africa 0.0402 GBP
KRSouth Korea 0.0167 GBP
SSSouth Sudan 0.2198 GBP
ESSpain 0.0329 GBP
LKSri Lanka 0.3193 GBP
SHSt. Helena 0.0785 GBP
KNSt. Kitts & Nevis 0.2198 GBP
LCSt. Lucia 0.1984 GBP
PMSt. Pierre & Miquelon 0.1005 GBP
VCSt. Vincent & Grenadines 0.1582 GBP
SDSudan 0.2565 GBP
SRSuriname 0.1834 GBP
SESweden 0.0406 GBP
CHSwitzerland 0.0502 GBP
SYSyria 0.2465 GBP
STSão Tomé & Príncipe 0.0201 GBP
TWTaiwan 0.0628 GBP
TJTajikistan 0.3021 GBP
TZTanzania 0.2251 GBP
THThailand 0.0147 GBP
TLTimor-Leste 0.1231 GBP
TGTogo 0.1457 GBP
TKTokelau 0.0209 GBP
TOTonga 0.1413 GBP
TTTrinidad & Tobago 0.1984 GBP
TNTunisia 0.2411 GBP
TMTurkmenistan 0.2487 GBP
TCTurks & Caicos Islands 0.1335 GBP
TVTuvalu 0.3663 GBP
TRTürkiye 0.0064 GBP
VIU.S. Virgin Islands 0.0309 GBP
UGUganda 0.2565 GBP
UAUkraine 0.1465 GBP
AEUnited Arab Emirates 0.0764 GBP
GBUnited Kingdom 0.0364 GBP
USUnited States 0.0176 GBP
ZZUnknown Region 0.0691 GBP
UYUruguay 0.0890 GBP
UZUzbekistan 0.3349 GBP
VUVanuatu 0.1382 GBP
VEVenezuela 0.1105 GBP
VNVietnam 0.1858 GBP
WFWallis & Futuna 0.0744 GBP
YEYemen 0.1444 GBP
ZMZambia 0.2193 GBP
ZWZimbabwe 0.1884 GBP