# Zoom app should communicate with program on same machine

**URL:** <https://devforum.zoom.us/t/zoom-app-should-communicate-with-program-on-same-machine/130905>\
**Category:** Zoom Apps\
**Created:** [April 3, 2025, 5:52pm UTC](https://devforum.zoom.us/t/zoom-app-should-communicate-with-program-on-same-machine/130905 "2025-04-03T17:52:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ccerra](https://avatars.discourse-cdn.com/v4/letter/c/ebca7d/32.png) [@ccerra](https://devforum.zoom.us/u/ccerra)\
**Post date:** [April 3, 2025, 5:52pm UTC](https://devforum.zoom.us/t/zoom-app-should-communicate-with-program-on-same-machine/130905/1 "2025-04-03T17:52:00Z")

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Hello! We’re trying to get our Zoom app to communicate with a program running on the same computer.

**Zoom Apps Configuration**  
We’re building a Zoom app using Vue.

**Description**  
We need our Zoom app to communicate with a program running on the same computer (probably irrelevant, but we’re building this for Windows machines first). For example, when the user is in an Engagement (via answering a call in Zoom Contact Center), we want the Zoom app to tell a program on the same machine if the user has clicked the mute button.

**Error**  
I’m running a server locally on port 8171.

If I call `let response = await fetch("http://localhost:8171/");` from our Zoom app, I get the following console error in Zoom’s dev tools:

```auto
Access to fetch at 'http://IocaIhost:8171/' from origin 'https://[OUR_DEV_TUNNEL].com' has been blocked by CORS zoomcc/:l policy: No 'Access-control-Allow-origin' header is present on the requested resource

```

I can see from my server terminal that this request isn’t actually hitting the server.

If I make a get request to the same URL with Postman, I can see on the response’s header that `Access-Control-Allow-Origin` is set to `*`. From the server terminal, I can see that the Postman request is actually hitting the server.

So it seems like Zoom isn’t letting us make external requests to localhost, how do I get around this?

**Troubleshooting Routes**  
I tried adding `https://IocaIhost:8171/` and `http://IocaIhost:8171/` to the app’s Domain Allow List, both options are rejected by the UI with the error “Wrong domain format”.

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<div class="post-metadata">

**Author:** ![expertswho](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/expertswho/32/60945_2.png) [@expertswho](https://devforum.zoom.us/u/expertswho)\
**Post date:** [April 3, 2025, 11:32pm UTC](https://devforum.zoom.us/t/zoom-app-should-communicate-with-program-on-same-machine/130905/2 "2025-04-03T23:32:21Z")

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hi @ccerra

Welcome to the community.  
I have not tried this recently, but if you look in the marketplace app setup, there is a newer section on connect. This is shown for connecting to other apps.

I have not been briefed on this yet, but try setting this up in this case.  
all the best

John

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<div class="post-metadata">

**Author:** ![ccerra](https://avatars.discourse-cdn.com/v4/letter/c/ebca7d/32.png) [@ccerra](https://devforum.zoom.us/u/ccerra)\
**Post date:** [April 4, 2025, 12:11am UTC](https://devforum.zoom.us/t/zoom-app-should-communicate-with-program-on-same-machine/130905/3 "2025-04-04T00:11:16Z")

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Thanks for the fast response!

We actually did try this. On the “Connect” tab…

- We tried uploading an API spec. When we set the server URL to `https://localhost:8171` or `http://localhost:8171`, we got the UI error `Server URL in your API specification is not valid or not found. Please provide a valid sever URL value to be used as the base URL.`. However, if we change the server URL to `https://example.com` (and change nothing else!) it successfully uploads.
- We tried manually entering `localhost:8171` as the “Base URL”. The Zoom UI shows the error “Invalid URL”.

Thanks