NOTE: This section of the docs describes Applications V2 functionality.

A Vonage API application contains the security and configuration information you need to connect to Vonage endpoints and use the Vonage APIs.

Each Vonage application created can support multiple capabilities - for example you can create an Application that supports using the Voice, Messages and RTC APIs.

Application Overview
Application Overview

To illustrate the use of Vonage applications, a brief summary for creating and using a Vonage voice application is given here:

  1. Create a Vonage application using the CLI, the Dashboard or the Application API.
  2. Make sure you configure your webhook URLs. Vonage will call back on these URLs with important information.
  3. Associate a Vonage number with your Vonage application.
  4. Write your web application. Implement the webhook endpoints you configured in step 2, using the Vonage APIs as required.

For instance, if you want to create an application that forwards inbound calls to a destination phone, you would perform the following steps:

  1. You create a Vonage application that has voice capabilities.
  2. You configure the answer and event webhook URLs.
  3. You associate a Vonage number with your Vonage application.
  4. You implement a web application that responds to callbacks on the webhook URLs.
  5. When an inbound call is made to the Vonage number associated with the Vonage application, an NCCO is returned on the answer_url.

Other types of application, such as those with Messages and Dispatch capabilities, have a slightly different process which is described in the relevant sections of this documentation.

The following sections explain Vonage applications in more detail.


Each application has the following:

Name Description
id Used to identify each application and used in conjunction with private_key to generate JWTs.
name The application name.
capabilities Describes the types of functionality this application will support. The capabilities voice, messages, rtc, vbc. Any number of these capabilities can be supported in one application. You also set webhooks for each capability specified. Vonage sends and retrieves information via the webhook endpoints.
keys Contains private_key and public_key. You use the private key to generate the JWTs used to authenticate your calls to the Vonage APIs. The public key is used by Vonage to authenticate the JWT in your requests to Vonage API.


A Vonage application can use various APIs, including Voice, Messages and Dispatch, Conversation, and Client SDK.

When creating an application you can specify the capabilities you want your application to support. For each capability you can set webhooks depending on what capabilities you want, for example for an application with an rtc capability you could specify an event URL to receive RTC events. If your application also needed to use voice capabilities you could also potentially set an Answer URL to receive a call answered webhook, a fallback URL in case your Answer URL fails, and another Event URL to receive voice call related events.

A summary of capabilities is given in the following table:

Capability Description
voice Used to support Voice capabilities.
messages Used to support Messages and Dispatch API capabilities.
rtc Used to support WebRTC capabilities. Typically for use with Client SDK.
vbc Used to determine pricing, but currently has no other capabilities.


The webhook URLs you provide when creating an application depend on the application capabilities required. The following table summarizes the webhooks:

Capability API used Webhooks available
voice Voice answer_url, fallback_answer_url, event_url
messages Messages and Dispatch inbound_url, status_url
rtc Client SDK event_url
vbc VBC None

Webhook types

The following table describes webhooks available per capability:

Capability Webhook API Example Description
voice answer_url Voice https://example.com/webhooks/answer The URL that Vonage make a request to when a call is placed/received. Must return an NCCO.
voice fallback_answer_url Voice https://example.com/webhooks/fallback If the fallback_answer_url is set, Vonage makes a request to it if the answer_url is offline or returns an HTTP error code or the event_url is offline or returns an error code and an event is expected to return an NCCO. The fallback_answer_url must return an NCCO. If your fallback_answer_url fails after two attempts for an initial NCCO, the call is ended. If your fallback_answer_url fails after two attempts for a call in progress, the call flow is continued.
voice event_url Voice https://example.com/webhooks/event Vonage will send call events (e.g. ringing, answered) to this URL.
messages inbound_url Messages, Dispatch https://example.com/webhooks/inbound Vonage will forward inbound messages to this URL.
messages status_url Messages, Dispatch https://example.com/webhooks/status Vonage will send message status updates (for example, delivered, seen) to this URL.
rtc event_url Client SDK, Conversation https://example.com/webhooks/rtcevent Vonage will send RTC events to this URL.
vbc None Voice endpoint None Not used

Webhook timeouts

For the voice capability only, you can set timeouts on webhooks. There are two timeouts that can be specified: connection_timeout and socket_timeout. These parameters apply to the answer, event, and fallback webhooks, and are specified in milliseconds. The following table provides further information:

Parameter Example Description
connection_timeout 1000 If Vonage can't connect to the webhook URL for this specified amount of time, then Vonage makes one additional attempt to connect to the webhook endpoint. This is an integer value specified in milliseconds.
socket_timeout 3000 If a response from the webhook URL can't be read for this specified amount of time, then Vonage makes one additional attempt to read the webhook endpoint. This is an integer value specified in milliseconds.

When creating or updating an application these can be set directly, or updated as required, for example:

  "capabilities": {
    "voice": {
      "webhooks": {
        "answer_url": {
          "address": "https://example.com/webhooks/answer",
          "http_method": "POST",
          "connection_timeout": 500,
          "socket_timeout": 3000
        "fallback_answer_url": {
          "address": "https://fallback.example.com/webhooks/answer",
          "http_method": "POST",
          "connection_timeout": 500,
          "socket_timeout": 3000
        "event_url": {
          "address": "https://example.com/webhooks/event",
          "http_method": "POST",
          "connection_timeout": 500,
          "socket_timeout": 3000

If these values are not specified when creating or updating the application, then default values are applied. The default values for these timeouts depend on the webhook concerned, as shown in the following table:

Webhook Default connection_timeout Default socket_timeout
answer 1000 5000
event 1000 10000
fallback 1000 5000

NOTE: Timeouts are specified in milliseconds.

There is further explanation of webhook timeouts in the webhook documentation.

Creating applications

There are four main ways to create an application:

  1. In the Vonage Dashboard. Applications are then listed in the your applications section of the Dashboard.
  2. Using the Vonage CLI.
  3. Using the Application API.
  4. Using one of the Vonage Server SDKs.

Managing applications using the CLI

Code Snippets