Our Product – Call In App

Real-Time APIs

Automate the lifecycle of voice telecom services, including provisioning (phone numbers, number groups, SIP endpoints), voice calls, and call recordings.

Backward Compatible

Migrate quickly from your price-gouging provider. Our XML syntax and libraries support existing voice functions like , , , and more.

Language Support

Use your favorite programming language. We support client libraries and software developer kits (SDKs) for C#, Go, Java, JavaScript, node.js, PHP, Python, React Native, and Ruby.

Carrier Support

Take advantage of the best prices, international reach, and service of your choice. CallinApp utilizes a diversity of backend telecom carriers. In addition, CallinApp offers a 'bring your own carrier' model integrating its API layer with supported providers.

SIP Connectivity

Build applications that include SIP endpoints. Our APIs let you place and manage SIP calls in addition to regular PSTN calls. Our Domain Apps feature enables you to receive SIP traffic at a hosted domain and route calls to your applications using APIs.

SIP Trunking

Integrate SIP endpoints for use with existing VoIP client applications, PBX, or call center systems. Route incoming PSTN calls to SIP endpoints and initiate outbound PSTN calls from SIP endpoints.

Dialogflow Integration

Create next-generation AI voice agents utilizing a chatbot framework. CallinApp enables you to assign telephone numbers directly to Google Dialogflow applications that interact with speech-to-text and text-to-speech capabilities.

Built-in Functions

Create auto-answer or voice recording applications with simple XML declarations. Host XML documents in your Space without the need for additional programming or hosting infrastructure.

Unrivaled Support

We are the original geeks of software-defined telecom and we adhere to our open-source ethos of building community to foster innovation. Chat in real-time with technology experts and fellow developers in our open Slack community.

Case Study

CallinApp unlocks advanced voice capabilities and makes it easy to build your application.

Advanced IVR

Build Interactive Voice Response (IVR) systems with APIs that utilize both touch-tone (DTMF) and voice inputs to interact with your custom applications.

AI Agents

Create telephone AI agents with native integration of voice telephony, text-to-speech, speech-to-text, and AI chatbot frameworks like Google Dialogflow.

Account Verification OTP

When a new user signs up for your application, you want to make sure their contact information is accurate.</p> <p>One of the best to verify is account verification via SMS or OTP. Before a registration is fully completed, your application sends the user a one-time passcode via SMS. The user then enters the code on your website to complete their registration.

Automated Survey

You can build automated surveys that call your customer at the point of service to get immediate feedback. It can also integrate directly with your CRM and customer database.

Conference & Broadcast

Help your company stay organized with two helpful features - voice conference and broadcast. In a few minutes you can build a moderated conference line that allows people to listen, speak or moderate during the call. Voice Broadcasting allows you to immediately broadcast a pre-recorded voice message to a list of contacts.

Click to Call

Click-to-call converts your website's users into engaged customers by creating an easy way for your customers to contact your sales and support teams right on your website.

VoIP Integration

Use SIP trunking and routing to save money on public switched telephone network (PSTN) connectivity to VoIP client applications, PBX, and call center systems.

Appointment Reminder

Appointment reminders allow you to automate the process of reaching out to your customers in advance of an upcoming appointment. Whether you're a dentist, doctor, cable company, or car repair shop, you can use automated appointment reminders to save time and money.

ETA Notifications

You can use ETA Notifications to keep customers up to date on the status of their order or request. More and more services are relying on SMS as the primary way of communicating with their customers for on-demand purchases.

Dynamic Call Center

Create a seamless customer service experience by assigning callers to specialized agents within your call center. You no longer have to handle the complicated task workflow features necessary to build a dynamic call center.