No host parameter for App Bridge in the URL of the app link

Technical Q&A

Topic summary

Issue: After updating to App Bridge 3.0, the app fails to initialize when opened from the Shopify admin’s lower-left app name link because the URL lacks the host query parameter.

Reproduction:

  • Works: Opening via a URL like /admin/apps/hello-139/top where host exists in the query; code reads it with URL(…).searchParams.get(“host”).
  • Fails: Clicking the app name link opens /admin/apps/hello-139?appLoadId=…, which does not include host, so host resolves to null and App Bridge throws: APP::ERROR::INVALID_CONFIG: not a valid host, please use the value provided by Shopify.

Context:

  • “host” is a query parameter used to initialize App Bridge 3.0.
  • An image (screenshot) is central to show the exact link location used to open the app.

Status:

  • No solution or explanation provided in the thread.
  • Another participant reports the same problem and asks if a fix was found.

Open questions:

  • Why Shopify’s link omits host and how to correctly obtain/use host (or appLoadId) for App Bridge 3.0 initialization in this flow.
Summarized with AI on December 12. AI used: gpt-5.
1

I am trying to update my app to App Bridge 3.0 following the instructions in the following notification:
https://shopify.dev/docs/api/app-bridge/previous-versions/updating-overview?locale=ja#update-your-app

When I access the app with the following URL:
https://???.myshopify.com/admin/apps/hello-139/top

I can retrieve the host parameter from the URL and initialize App Bridge using the following code:

new URL(window.location.href).searchParams.get("host");

However, when I click the link for the app name in the lower left corner of the store (see the image), the URL is as follows, and the host parameter becomes null, resulting in the following error:
https://???.myshopify.com/admin/apps/hello-139?appLoadId=???

![shopify.png|1509x739](upload://259ceB0dLunluXi4OnGabfoAQOp.png)

AppBridgeError APP::ERROR::INVALID_CONFIG: not a valid host, please use the value provided by Shopify

Why is this happening? How can I resolve it?

1 Like
2

Hi nemmy, I faced the same problem, did you find any solution?