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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 8.4128 CZK
ALAlbania 2.6941 CZK
DZAlgeria 6.8516 CZK
ASAmerican Samoa 2.8752 CZK
ADAndorra 2.0384 CZK
AOAngola 1.9087 CZK
AIAnguilla 3.9641 CZK
AGAntigua & Barbuda 5.4323 CZK
ARArgentina 2.2170 CZK
AMArmenia 5.1999 CZK
AWAruba 3.2300 CZK
AUAustralia 0.7414 CZK
ATAustria 1.2724 CZK
AZAzerbaijan 7.6053 CZK
BSBahamas 1.7888 CZK
BHBahrain 1.0277 CZK
BDBangladesh 11.2415 CZK
BBBarbados 5.9658 CZK
BYBelarus 4.3141 CZK
BEBelgium 1.9821 CZK
BZBelize 5.0922 CZK
BJBenin 5.4299 CZK
BMBermuda 5.9658 CZK
BTBhutan 7.6469 CZK
BOBolivia 5.0653 CZK
BABosnia & Herzegovina 3.4503 CZK
BWBotswana 3.2129 CZK
BRBrazil 0.6142 CZK
IOBritish Indian Ocean Territory 2.7896 CZK
VGBritish Virgin Islands 5.9658 CZK
BNBrunei 1.3777 CZK
BGBulgaria 3.3646 CZK
BFBurkina Faso 4.4780 CZK
BIBurundi 9.6901 CZK
KHCambodia 7.3410 CZK
CMCameroon 6.0196 CZK
CACanada 0.5139 CZK
CVCape Verde 4.6640 CZK
KYCayman Islands 5.5058 CZK
CFCentral African Republic 2.1289 CZK
TDChad 7.1110 CZK
CLChile 1.0008 CZK
CNChina 0.5824 CZK
COColombia 0.4600 CZK
KMComoros 7.7815 CZK
CGCongo - Brazzaville 4.7717 CZK
CDCongo - Kinshasa 6.7537 CZK
CKCook Islands 2.7725 CZK
CRCosta Rica 0.6729 CZK
HRCroatia 3.1689 CZK
CUCuba 2.0041 CZK
ANCuraçao 2.9364 CZK
CWCuraçao 6.7293 CZK
CYCyprus 2.3711 CZK
CZCzechia 1.2113 CZK
CICôte d’Ivoire 6.2399 CZK
DKDenmark 1.1281 CZK
DJDjibouti 2.8630 CZK
DMDominica 4.6248 CZK
DODominican Republic 2.9511 CZK
ECEcuador 6.3867 CZK
EGEgypt 6.8271 CZK
SVEl Salvador 2.7896 CZK
GQEquatorial Guinea 4.4046 CZK
EREritrea 2.2733 CZK
EEEstonia 1.1476 CZK
SZEswatini 3.7439 CZK
ETEthiopia 6.7293 CZK
FKFalkland Islands 1.6003 CZK
FOFaroe Islands 1.1697 CZK
FJFiji 4.1305 CZK
FIFinland 1.0277 CZK
FRFrance 1.2088 CZK
GFFrench Guiana 1.3116 CZK
PFFrench Polynesia 1.9698 CZK
GAGabon 6.5775 CZK
GMGambia 3.8247 CZK
GEGeorgia 2.9511 CZK
DEGermany 2.1313 CZK
GHGhana 5.3589 CZK
GIGibraltar 1.5612 CZK
GRGreece 1.0669 CZK
GLGreenland 0.2765 CZK
GDGrenada 5.5058 CZK
GPGuadeloupe 2.7162 CZK
GUGuam 3.0098 CZK
GTGuatemala 4.7717 CZK
GNGuinea 5.8728 CZK
GWGuinea-Bissau 5.4323 CZK
GYGuyana 5.8728 CZK
HTHaiti 5.9658 CZK
HNHonduras 3.2300 CZK
HKHong Kong SAR China 1.3728 CZK
HUHungary 1.5906 CZK
ISIceland 1.5441 CZK
INIndia 1.8230 CZK
IDIndonesia 9.8614 CZK
IRIran 8.3687 CZK
IQIraq 8.2293 CZK
IEIreland 1.0277 CZK
ILIsrael 4.8940 CZK
ITItaly 1.1697 CZK
JMJamaica 2.9217 CZK
JPJapan 1.2357 CZK
JOJordan 7.6346 CZK
KZKazakhstan 8.2586 CZK
KEKenya 2.9364 CZK
KIKiribati 1.2455 CZK
XKKosovo 6.1175 CZK
KWKuwait 7.0351 CZK
KGKyrgyzstan 6.2863 CZK
LALaos 3.0832 CZK
LVLatvia 1.2235 CZK
LBLebanon 1.1746 CZK
LSLesotho 5.7994 CZK
LRLiberia 4.4046 CZK
LYLibya 7.8010 CZK
LILiechtenstein 0.9764 CZK
LTLithuania 0.9935 CZK
LULuxembourg 2.4959 CZK
MOMacao SAR China 1.0767 CZK
MGMadagascar 9.5580 CZK
MWMalawi 6.4234 CZK
MYMalaysia 3.6705 CZK
MVMaldives 1.5416 CZK
MLMali 5.2121 CZK
MTMalta 1.3410 CZK
MHMarshall Islands 1.3777 CZK
MQMartinique 1.2235 CZK
MRMauritania 5.5792 CZK
MUMauritius 3.7806 CZK
MXMexico 1.7618 CZK
FMMicronesia 1.8059 CZK
MDMoldova 3.2619 CZK
MCMonaco 3.2154 CZK
MNMongolia 7.1893 CZK
MEMontenegro 3.5188 CZK
MSMontserrat 3.0832 CZK
MAMorocco 1.7618 CZK
MZMozambique 3.0832 CZK
MMMyanmar (Burma) 9.0245 CZK
NANamibia 1.0375 CZK
NRNauru 4.1305 CZK
NPNepal 6.0196 CZK
NLNetherlands 1.8671 CZK
NCNew Caledonia 2.9021 CZK
NZNew Zealand 1.0277 CZK
NINicaragua 2.8630 CZK
NENiger 6.8834 CZK
NGNigeria 8.2219 CZK
NUNiue 3.9764 CZK
KPNorth Korea 2.0530 CZK
MKNorth Macedonia 2.1558 CZK
NONorway 0.8809 CZK
OMOman 4.2822 CZK
PKPakistan 8.8092 CZK
PWPalau 2.8018 CZK
PSPalestinian Territories 7.2333 CZK
PAPanama 3.5971 CZK
PGPapua New Guinea 4.7423 CZK
PYParaguay 2.0555 CZK
PEPeru 3.0832 CZK
PHPhilippines 5.1852 CZK
PLPoland 0.6118 CZK
PTPortugal 0.6436 CZK
PRPuerto Rico 2.5571 CZK
QAQatar 2.5693 CZK
RORomania 1.1330 CZK
RURussia 9.8810 CZK
RWRwanda 6.8051 CZK
RERéunion 1.5416 CZK
WSSamoa 3.4503 CZK
SMSan Marino 1.3703 CZK
SASaudi Arabia 4.6982 CZK
SNSenegal 5.7994 CZK
RSSerbia 4.7717 CZK
SCSeychelles 2.6428 CZK
SLSierra Leone 5.7260 CZK
SGSingapore 1.1281 CZK
SXSint Maarten 2.2904 CZK
SKSlovakia 1.2431 CZK
SISlovenia 3.8247 CZK
SBSolomon Islands 2.0555 CZK
SOSomalia 5.2121 CZK
ZASouth Africa 1.1746 CZK
KRSouth Korea 0.4894 CZK
SSSouth Sudan 6.4234 CZK
ESSpain 0.9054 CZK
LKSri Lanka 9.1616 CZK
SHSt. Helena 2.2953 CZK
KNSt. Kitts & Nevis 5.9658 CZK
LCSt. Lucia 5.7994 CZK
PMSt. Pierre & Miquelon 2.9364 CZK
VCSt. Vincent & Grenadines 4.6248 CZK
SDSudan 7.4952 CZK
SRSuriname 5.3589 CZK
SESweden 1.1868 CZK
CHSwitzerland 1.4535 CZK
SYSyria 7.2040 CZK
STSão Tomé & Príncipe 0.5873 CZK
TWTaiwan 1.8352 CZK
TJTajikistan 8.8288 CZK
TZTanzania 6.5775 CZK
THThailand 0.4282 CZK
TLTimor-Leste 3.5971 CZK
TGTogo 4.2578 CZK
TKTokelau 0.6118 CZK
TOTonga 4.1305 CZK
TTTrinidad & Tobago 5.7994 CZK
TNTunisia 7.0474 CZK
TMTurkmenistan 5.3540 CZK
TCTurks & Caicos Islands 3.9005 CZK
TVTuvalu 3.8247 CZK
TRTürkiye 0.1860 CZK
VIU.S. Virgin Islands 0.9029 CZK
UGUganda 6.9128 CZK
UAUkraine 4.2822 CZK
AEUnited Arab Emirates 2.2341 CZK
GBUnited Kingdom 0.9812 CZK
USUnited States 0.5139 CZK
ZZUnknown Region 2.0188 CZK
UYUruguay 2.6012 CZK
UZUzbekistan 9.4821 CZK
VUVanuatu 4.0376 CZK
VEVenezuela 3.2300 CZK
VNVietnam 5.4299 CZK
WFWallis & Futuna 1.8132 CZK
YEYemen 4.2211 CZK
ZMZambia 6.4087 CZK
ZWZimbabwe 4.4511 CZK