Azure Static Web Apps
An Azure service that provides streamlined full-stack web app development.
Static Web App linked Function App backend returns 404 on /api/* routes
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Dean Ackerman
0
Reputation points
I have an Azure Static Web App named smarttraderai-portal-2026 and a linked Azure Function App named smarttraderai-api-2026v3 in resource group SmartTraderAI-portal-rg.
Current verified state:
- Static Web App APIs page shows Production linked to Function App smarttraderai-api-2026v3
- Function App smarttraderai-api-2026v3 shows enabled HTTP functions in Azure:
- admin-users
- admin-log-summaries
- admin-trade-signals
- logs-upload
- profile-bootstrap
- Static Web App GitHub workflow is configured for external linked backend with api_location: ""
- Static Web App deploy succeeds
- Function App package is deployed successfully and site/wwwroot contains:
- host.json
- package.json
- package-lock.json
- dist
- node_modules
- The Function App is running and functions are loaded
Problem:
- Requests through the Static Web App still return Azure platform 404 Not Found
- Example failing URL: https://icy-dune-0882d5210.1.azurestaticapps.net/api/admin/users
Expected:
- /api/* requests on the Static Web App should forward to the linked Function App backend
Actual:
- Static Web App returns 404 Not Found
Already attempted:
- unlink and relink backend multiple times
- removed managed SWA API deployment from workflow
- set api_location to ""
- redeployed Static Web App
- recreated Function App backend
- verified backend functions are present and enabled
Resources:
- Subscription: Pay-As-You-Go
- Resource Group: SmartTraderAI-portal-rg
- Static Web App: smarttraderai-portal-2026
- Function App: smarttraderai-api-2026v3
- Static Web App hostname: icy-dune-0882d5210.1.azurestaticapps.net
Has anyone seen linked backend routing fail like this even when the SWA APIs page shows the correct linked Function App and the backend functions are visible/enabled?
Azure Static Web Apps
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Aditya N 2,960 Reputation points Microsoft External Staff Moderator2026-04-13T01:20:56.52+00:00 Hello @Dean Ackerman
Thank you for reaching out Microsoft Q&A. We understand that you're facing 404 error, we're looking into your issue. We'll get back to you shortly.
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Golla Venkata Pavani 4,830 Reputation points Microsoft External Staff Moderator2026-04-16T20:57:46.8733333+00:00 Hello @Dean Ackerman
Thanks for sharing the detailed setup and troubleshooting steps. Currently what you’re seeing is expected behavior and is most commonly caused by a route mismatch between Azure Static Web Apps and the linked Azure Function App.
When you use Bring Your Own Functions with Azure Static Web Apps, the platform forwards
/api/*requests to the linked Function App exactly as they are, without rewriting or mapping URL paths. This means the requested path must exactly match an HTTP trigger route in the Function App, otherwise a 404 is returned by the Static Web Apps platform.
In your case:- Your functions are named:
admin-users,admin-log-summaries, etc. - By default, Azure Functions exposes HTTP triggers at : /api/<function-name>
- So the valid endpoint is: /api/admin-users
- However, the request being made is:
/api/admin/users
That route does not exist in the Function App, so Static Web Apps correctly returns 404 Not Found, even though the backend is linked and running.
Option 1:
Update frontend URLs (fastest) Change frontend calls to match the default function routes, for example:fetch('/api/admin-users')Option 2:
Define explicit HTTP routes in the Function App (recommended for clean URLs) Configure a customrouteon each HTTP trigger so the Function App explicitly exposes paths like/admin/users. Azure Functions supports custom routes via the HTTP trigger configuration. After redeploying the Function App,/api/admin/userswill work as expected.Reference:
https://learn.microsoft.com/en-us/azure/static-web-apps/functions-bring-your-own
https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-http-webhook-trigger?tabs=python-v2%2Cisolated-process%2Cnodejs-v4%2Cfunctionsv2&pivots=programming-language-csharp#customize-the-http-endpointKindly let us know if the above helps or you need further assistance on this issue.
Please "upvote" if the information helped you. This will help us and others in the community as well.
- Your functions are named:
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Golla Venkata Pavani 4,830 Reputation points Microsoft External Staff Moderator
2026-04-17T20:53:08.2733333+00:00 Hello @Dean Ackerman
I'm just reaching out to see if your issue has been resolved or if you've had a chance to review my previous comment?
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