The Flowroute API provides core calling and messaging services, including phone numbers throughout North America, outbound and inbound calling and call masking capabilities, SMS, and related information services. Flowroute is a certificated SIP telecommunications provider.


The SMS API provides SMS communication to existing applications. This REST interface uses the SMPP protocol to send messages between entities. SMSAPI offers bulk services, email SMS, 5 second delivery, and global support of over 800 mobile providers in 200 countries.


Helprace API lets developers incorporate client applications and integrate its services into their applications. Helprace provides cloud-based customer service application including helk desk, community, feedback and ticketing system.


Massenversand.de is an international SMS messaging service based in Germany. Their SMS gateway services provide users with bulk SMS capabilities, a web payment system, and HTTP and email integration for receiving SMS. The ability to send messages using international characters is also supported. Most of the service's functions are available via API. Much of the massenversand.de website's content and API documentation is available exclusively in German.


The Octopush SMS API allows developers to integrate sending and tracking messages with applications, software and information systems. With the Octopush API, messages can be sent to more than 200 countries through direct connection to Octopush’s infrastructure.

ClickSend SMS

ClickSend is a cloud-based SMS service. It offers fast delivery times by using direct, high performance routes. The ClickSend SMS API allows users to send SMS programmatically by integrating the service into their applications, websites, or software. Possible uses include billing reminders, following up with customers, delivery notifications, and alert sending.


31Events is a calendaring service that sends invites directly to a customers' calendars. If the invite is accepted, the recipient is automatically signed up for the event. The service aims to monitor large groups along with accept or deny status and hopes to Increased Webinar attendance. The 31Events API uses REST calls, returns JSON, and allows users to make a variety of calls including create, update, get , list and delete events, as well as manipulate account information. An account is required with service.


HSL (Hay Systems Ltd.) SMS provides a messaging gateway that can easily be integrated with other applications to allow them to send and receive SMS. HSL SMS is a versatile service that can be used for emergency alerts, M2M (machine-to-machine) calls, staff communications, customer promotions, two-factor authentication, and more. Integration can be accomplished using a variety of protocols, including REST, SOAP, SMPP, and SMTP.


Skebby is a cloud-based SMS service that allows users to send and receive SMS online. Developers can integrate Skebby's SMS gateway with their own website or application using its API. Calls may be issued in REST, SOAP, or SMTP format, and code examples are available in ASP, PHP, and HTML.


Fastsms provides cloud-based SMS services that operate over tier 1 UK network routes. Pricing for texts starts at 2.1 pence per message. Customer support is available at all times. Developers can integrate fastsms into their own applications and systems using REST, FTP/SCP, or SMTP calls.