# Calling Extensions SDK

**URL:** <https://community.hubspot.com/t/calling-extensions-sdk/69201>\
**Category:** APIs & Integrations\
**Created:** [November 14, 2022, 12:49pm UTC](https://community.hubspot.com/t/calling-extensions-sdk/69201 "2022-11-14T12:49:21Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![datalink](https://avatars.discourse-cdn.com/v4/letter/d/5e9695/32.png) [@datalink](https://community.hubspot.com/u/datalink)\
**Post date:** [November 14, 2022, 12:49pm UTC](https://community.hubspot.com/t/calling-extensions-sdk/69201/1 "2022-11-14T12:49:21Z")

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I want to use the Calling Extensions SDK. First step is:

1. [Create](https://developers.hubspot.com/docs/faq/how-do-i-create-an-app-in-hubspot) a HubSpot application and [setup a test](https://developers.hubspot.com/docs/faq/how-do-i-create-a-test-account) portal

This ios done. Second step is:

2. [Integrate](https://github.com/HubSpot/calling-extensions-sdk#integrate-calling-extensions-sdk) the Calling Extensions SDK with your call widget.

But how to integret? There is only the marketplace. I can’t get my own app.

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**Author:** ![Jaycee\_Lewis](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jaycee_lewis/32/61352_2.png) [@Jaycee\_Lewis](https://community.hubspot.com/u/Jaycee_Lewis)\
**Post date:** [November 16, 2022, 7:12pm UTC](https://community.hubspot.com/t/calling-extensions-sdk/69201/2 "2022-11-16T19:12:52Z")

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Hi, @datalink 👋 Did you get this worked out? The widget is created on your end as part of your app.

Here are some details from the documentation — [Building your app](https://developers.hubspot.com/docs/api/crm/extensions/calling-sdk#:~:text=When-,building%20your%20app,-%2C%20there%20are%20some)

When building your app, there are some considerations to keep in mind:

- You will need to have a web app that can be displayed inside of an iframe because HubSpot will not process any content of the iframe, so you can’t set the iframe URL to a backend SIP service.
- The height and width parameters set through the settings API will determine the size of the iframe. Windows with a height of 600px and a width of 400px work best for the widest range of browser window sizes, including smaller screens.
- You should make sure that error conditions appear inside the iframe. This is so your app can alert users about audio issues, network problems, or other errors.

Have fun building! — Jaycee

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**Author:** ![datalink](https://avatars.discourse-cdn.com/v4/letter/d/5e9695/32.png) [@datalink](https://community.hubspot.com/u/datalink)\
**Post date:** [November 16, 2022, 8:22pm UTC](https://community.hubspot.com/t/calling-extensions-sdk/69201/3 "2022-11-16T20:22:49Z")

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Hi Jaycee,

that’s not my point! How to show the content of the iframe? Simple example: an index.htm at my webspace, the index.htm outputs “Hello World”. How can I show “Hello World” inside the iframe? It seems not possible 🙂