article What is a callback in the Sinch Voice world? in Voice API

article What is a callback in the Sinch Voice world? in Voice API https://community.sinch.com/t5/Voice-API/What-is-a-callback-in-the-Sinch-Voice-world/ta-p/10250 <H2 class="lia-message-template-symptoms-zone">What’s a callback?</H2> <DIV class="lia-message-template-solution-zone"> <P>When using the Sinch Voice platform in many use cases a callback server will be required to control the flow of a call.  </P> <P> </P> <H2>Why do I need a callback server?</H2> <P>This is for you to be able to have control over certain elements, such as: authorising calls, routing calls, setting a cli (calling line identifier) to the receiving user.  It is mandatory to have a callback server for calling a PSTN destination</P> <H2> </H2> <H2>What do I need to implement a callback server?</H2> <P>You will need an application server that can parse incoming HTTP POST requests and return HTTP POST responses with SVAML commands (json) in the HTTP body.  Some example callback severs can be found here: <A href="https://github.com/sinch/voice-samples" target="_blank" rel="noopener">Sinch Github voice samples</A> or for simple testing you can use a service such as <A href="https://webhook.site" target="_blank" rel="noopener">https://webhook.site</A></P> <P> </P> <H2>Where do I configure my callback server URL?</H2> <P>You configure your application server URL in the Sinch Dashboard Voice & Video -> Apps -> In-app Voice & Video SDKs -> Callback URL.</P> <H2> </H2> <H2>What is SVAML?</H2> <P>SVAML is a call control markup language developed by Sinch. When your application or server receives a <A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/" target="_blank" rel="noopener">callback event</A> from the Sinch <SPAN>Voice</SPAN> platform, it can respond with a <EM>SVAML object</EM> to control the voice call. <SPAN><A href="https://developers.sinch.com/docs/voice/api-reference/svaml/" target="_blank" rel="noopener">https://developers.sinch.com/docs/voice/api-reference/svaml/</A></SPAN></P> <P> </P> <H2>What are the call events you send?</H2> <UL> <LI><A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/#tag/Callback-API/operation/ice" target="_self">ICE</A> (Incoming Call Event)  A call has been initiated, what action do you want to take?</LI> <LI><A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/#tag/Callback-API/operation/ace" target="_self">ACE</A> (Answered Call Event). Callback triggered by an the callee answering </LI> <LI><A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/#tag/Callback-API/operation/pie" target="_self">PIE</A> (Prompt Input Event). Callback triggered by a runMenu action.</LI> <LI><A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/#tag/Callback-API/operation/dice" target="_self">DICE</A> (Disconnect Call Event) The call has ended, here is the summary.</LI> </UL> <H2> </H2> <H2>Callback Diagram</H2> <P><SPAN>The figure below illustrates the lifecycle of a call and shows where both callbacks and REST API calls are located or can be made.</SPAN></P> <H2><span class="lia-inline-image-display-wrapper lia-image-align-center" image-alt="Screenshot 2022-11-16 at 09.37.49.png" style="width: 862px;"><img src="https://community.sinch.com/t5/image/serverpage/image-id/2280iCF7B2B41E70C826E/image-size/large?v=v2&px=999" role="button" title="Screenshot 2022-11-16 at 09.37.49.png" alt="Screenshot 2022-11-16 at 09.37.49.png" /></span></H2> <P> </P> <P>Developer documentation related to callbacks:  <A href="https://developers.sinch.com/docs/voice/api-reference/callbacks" target="_blank" rel="noopener">https://developers.sinch.com/docs/voice/api-reference/callbacks</A> </P> </DIV> Wed, 16 Nov 2022 15:25:55 GMT Roland_Ian 2022-11-16T15:25:55Z What is a callback in the Sinch Voice world? https://community.sinch.com/t5/Voice-API/What-is-a-callback-in-the-Sinch-Voice-world/ta-p/10250 <H2 class="lia-message-template-symptoms-zone">What’s a callback?</H2> <DIV class="lia-message-template-solution-zone"> <P>When using the Sinch Voice platform in many use cases a callback server will be required to control the flow of a call.  </P> <P> </P> <H2>Why do I need a callback server?</H2> <P>This is for you to be able to have control over certain elements, such as: authorising calls, routing calls, setting a cli (calling line identifier) to the receiving user.  It is mandatory to have a callback server for calling a PSTN destination</P> <H2> </H2> <H2>What do I need to implement a callback server?</H2> <P>You will need an application server that can parse incoming HTTP POST requests and return HTTP POST responses with SVAML commands (json) in the HTTP body.  Some example callback severs can be found here: <A href="https://github.com/sinch/voice-samples" target="_blank" rel="noopener">Sinch Github voice samples</A> or for simple testing you can use a service such as <A href="https://webhook.site" target="_blank" rel="noopener">https://webhook.site</A></P> <P> </P> <H2>Where do I configure my callback server URL?</H2> <P>You configure your application server URL in the Sinch Dashboard Voice & Video -> Apps -> In-app Voice & Video SDKs -> Callback URL.</P> <H2> </H2> <H2>What is SVAML?</H2> <P>SVAML is a call control markup language developed by Sinch. When your application or server receives a <A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/" target="_blank" rel="noopener">callback event</A> from the Sinch <SPAN>Voice</SPAN> platform, it can respond with a <EM>SVAML object</EM> to control the voice call. <SPAN><A href="https://developers.sinch.com/docs/voice/api-reference/svaml/" target="_blank" rel="noopener">https://developers.sinch.com/docs/voice/api-reference/svaml/</A></SPAN></P> <P> </P> <H2>What are the call events you send?</H2> <UL> <LI><A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/#tag/Callback-API/operation/ice" target="_self">ICE</A> (Incoming Call Event)  A call has been initiated, what action do you want to take?</LI> <LI><A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/#tag/Callback-API/operation/ace" target="_self">ACE</A> (Answered Call Event). Callback triggered by an the callee answering </LI> <LI><A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/#tag/Callback-API/operation/pie" target="_self">PIE</A> (Prompt Input Event). Callback triggered by a runMenu action.</LI> <LI><A href="https://developers.sinch.com/docs/voice/api-reference/voice/tag/Callback-API/#tag/Callback-API/operation/dice" target="_self">DICE</A> (Disconnect Call Event) The call has ended, here is the summary.</LI> </UL> <H2> </H2> <H2>Callback Diagram</H2> <P><SPAN>The figure below illustrates the lifecycle of a call and shows where both callbacks and REST API calls are located or can be made.</SPAN></P> <H2><span class="lia-inline-image-display-wrapper lia-image-align-center" image-alt="Screenshot 2022-11-16 at 09.37.49.png" style="width: 862px;"><img src="https://community.sinch.com/t5/image/serverpage/image-id/2280iCF7B2B41E70C826E/image-size/large?v=v2&px=999" role="button" title="Screenshot 2022-11-16 at 09.37.49.png" alt="Screenshot 2022-11-16 at 09.37.49.png" /></span></H2> <P> </P> <P>Developer documentation related to callbacks:  <A href="https://developers.sinch.com/docs/voice/api-reference/callbacks" target="_blank" rel="noopener">https://developers.sinch.com/docs/voice/api-reference/callbacks</A> </P> </DIV> Wed, 16 Nov 2022 15:25:55 GMT https://community.sinch.com/t5/Voice-API/What-is-a-callback-in-the-Sinch-Voice-world/ta-p/10250 Roland_Ian 2022-11-16T15:25:55Z Re: What is a callback in the Sinch Voice world? https://community.sinch.com/t5/Voice-API/What-is-a-callback-in-the-Sinch-Voice-world/tac-p/11278#M20 <P><SPAN>I created an account and obtained a demo number using a test app.  I completed the setup of a sample from </SPAN><A href="https://github.com/sinch/voice-api-webhook-nodejs" target="_new">https://github.com/sinch/voice-api-webhook-nodejs.</A><SPAN> Then, on the 'apps->settings' page, upon clicking 'Test a callback URL', I received an error 400. Additionally, there seems to be an issue with the GET method in the code. Could someone please guide me in resolving these issues?</SPAN></P> Mon, 03 Apr 2023 08:30:44 GMT https://community.sinch.com/t5/Voice-API/What-is-a-callback-in-the-Sinch-Voice-world/tac-p/11278#M20 tulsiwdv 2023-04-03T08:30:44Z Re: What is a callback in the Sinch Voice world? https://community.sinch.com/t5/Voice-API/What-is-a-callback-in-the-Sinch-Voice-world/tac-p/11282#M21 <P>Hi <A id="link_11" class="lia-link-navigation lia-page-link lia-user-name-link" href="https://community.sinch.com/t5/user/viewprofilepage/user-id/3429" target="_self" aria-label="View Profile of tulsiwdv"><SPAN class="">tulsiwdv</SPAN></A></P> <P> </P> <P>Thanks for using our code samples!</P> <P> </P> <P>There was a missing <FONT face="terminal,monaco">req</FONT> parameter in  the <FONT face="terminal,monaco">app.get</FONT>.</P> <P> </P> <P>Please clone the repo again, to receive the fix, or make this change to get the GET function to work.</P> <P> </P> <P><STRONG>From</STRONG></P> <P> </P> <LI-CODE lang="javascript">app.get('/', (res) => { res.send('GET Pong!'); });</LI-CODE> <P> </P> <P><STRONG>To</STRONG></P> <P> </P> <LI-CODE lang="javascript">app.get('/', (req, res) => { res.send('GET Pong!'); });</LI-CODE> <P> </P> <P>I would suggest to look in your ngrok you will see the 200OK  arriving even thought he dashboard reports 400 error</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="Screenshot 2023-04-03 at 12.36.04.png" style="width: 385px;"><img src="https://community.sinch.com/t5/image/serverpage/image-id/2953i9FD1D869D05C5D56/image-size/medium?v=v2&px=400" role="button" title="Screenshot 2023-04-03 at 12.36.04.png" alt="Screenshot 2023-04-03 at 12.36.04.png" /></span></P> <P> </P> <P>Let us know how you proceed</P> <P> </P> <P>Roland-Ian</P> Mon, 03 Apr 2023 10:40:30 GMT https://community.sinch.com/t5/Voice-API/What-is-a-callback-in-the-Sinch-Voice-world/tac-p/11282#M21 Roland_Ian 2023-04-03T10:40:30Z