Google Actions发送通知API报404：应用未找到/预览过期求助

Let’s break down this 404 error and walk through the most likely fixes, even if you’ve already checked some basics:

• Reactivate your app preview first
  The error message explicitly calls out a possible expired preview, and this is the most common culprit for this issue. Even if you think your preview should still be active, head to the Actions Console for your project, navigate to the Test tab, and click "Start testing" to regenerate the preview session. Test previews typically expire after 24 hours for unpublished apps, and using an expired session’s conversationId will trigger this exact error. Make sure you’re using a conversationId captured from the fresh preview session.

• Confirm your project ID is 100% correct in the API request
  Double-check that the parent field in your API call (formatted like projects/testaction-fff82/agent) matches your Actions project ID exactly. It’s easy to mistype or mix up project IDs with test aliases. Also, verify that the service account credentials you’re using are linked directly to the testaction-fff82 project—using credentials from a different project will cause the API to fail finding your app.

• Validate the conversation ID
  The conversationId you’re passing must be a valid, active ID from a recent user interaction with your Action. Old IDs from expired previews or test sessions won’t work. Capture the latest conversation.id value from a test conversation (you can log this during interaction) and use that in your conversations:send request.

• Rule out permission sync issues
  Even if you’ve set up permissions before, sometimes Google’s permission system can have delays or glitches. Try re-granting the Actions API Developer or Project Editor role to your service account in the Google Cloud Console, wait 5-10 minutes for changes to propagate, then retry the API call. Also, confirm your Actions project is properly linked to its corresponding Google Cloud project—mismatched links can lead to app not found errors.

• Test with the built-in API Explorer
  Use the API Explorer directly in the Google Actions documentation to send a test notification. This eliminates any issues with how you’re constructing the request in your code. If the Explorer works, the problem is likely in your local request setup; if it fails, you can be sure the issue is with your project/preview configuration.

If none of these steps resolve the error, check if your project in the Google Cloud Console is still active (not deleted or disabled)—accidental project deactivation can also trigger this 404.

内容的提问来源于stack exchange，提问作者aarcangeli