Sweden Central > Anthropic Files API now returning 404 for Anthropic Hosted models

Question

Sweden Central > Anthropic Files API now returning 404 for Anthropic Hosted models

Glen Anderson 25

From today, any Anthropic Files API related endpoints (eg. GET/POST https://<resource>.services.ai.azure.com/anthropic/v1/files) are returning 404 errors for Foundries hosted in Sweden Central specifically.

Some details:-

The Foundries we have tested against all have 'Hosted by Anthropic in Azure' models, so full API coverage including 'skills' and 'files' is expected (skills endpoints still works)
The issue started today - is not tenant specific - and is limited to Foundries hosted in Sweden Central (appears to be a routing issue/regression)
Things continue to work as expected for Foundries hosted in East US 2

Examples:-

Calling GET https://resource-in-eastus2.services.ai.azure.com/anthropic/v1/files?limit=1000
- Return 200 with message {"data":[],"has_more":false}
Calling GET https://resource-in-swedencentral.services.ai.azure.com/anthropic/v1/files?limit=1000
- Return 404 with message {"type":"error","error":{"type":"not_found_error","message":"Not found"},"request_id":"<requestId>"}

Impact:

Files cannot be uploaded and generated files cannot be downloaded when using Anthropic models hosted in Sweden Central

Update 13AUG26:

Begin to affect eastus2 several hours after swedencentral
Both endpoints were working again this morning, but both endpoints now return 404 again as of now
Issue remains

Kienan McLellan 15 Reputation points

2026-08-12T19:19:54.0133333+00:00

Now seeing the same error as you but within eastus2 when working with skills via API
Glen Anderson 25 Reputation points

2026-08-12T19:36:55.7466667+00:00

Thanks @Kienan McLellan - I've confirmed this on our our side in Sweden Central too. The /skills endpoints are now returning 502: Bad Gateway - Status Code: NotFound {"type":"error","error":{"type":"not_found_error","message":"Not found"},"request_id":"req_011CdyR1kiUjZMMUENysVCqh"}, but fortunately it's still possible to use existing skill ID's within chats that were uploaded prior to this regression.
Kienan McLellan 15 Reputation points

2026-08-12T19:39:48.34+00:00

Can you check your useast2 endpoint for /skills?

Glen Anderson 25

I've just re-checked /files in eastus2 - it worked earlier when I wrote this message, but now has the same broken behaviour as swedencentral - so, the issue has now spread to eastus2.

I've also tested skills as requested in eastus2 - no joy.

GET https://eastus2-foundry.services.ai.azure.com/anthropic/v1/skills  HTTP/1.1
404 Not Found
Content-Length: 117
Content-Type: application/json
x-should-retry: false
request-id: req_011CdyRYPfZbgLEettMXTFAp
x-robots-tag: none
azureml-served-by-cluster: hyena-eastus2-02
apim-request-id: 54a3f666-c5ca-44e0-95a6-0ddbf128e5cd
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
x-content-type-options: nosniff
x-ms-region: East US 2
Date: Wed, 12 Aug 2026 19:41:35 GMT

{"type":"error","error":{"type":"not_found_error","message":"Not found"},"request_id":"req_011CdyRYPfZbgLEettMXTFAp"}

1 answer

Your answer

Kienan McLellan 15 Reputation points

2026-08-12T19:19:54.0133333+00:00

Now seeing the same error as you but within eastus2 when working with skills via API
Glen Anderson 25 Reputation points

2026-08-12T19:36:55.7466667+00:00

Thanks @Kienan McLellan - I've confirmed this on our our side in Sweden Central too. The /skills endpoints are now returning 502: Bad Gateway - Status Code: NotFound {"type":"error","error":{"type":"not_found_error","message":"Not found"},"request_id":"req_011CdyR1kiUjZMMUENysVCqh"}, but fortunately it's still possible to use existing skill ID's within chats that were uploaded prior to this regression.
Kienan McLellan 15 Reputation points

2026-08-12T19:39:48.34+00:00

Can you check your useast2 endpoint for /skills?
Glen Anderson 25 Reputation points

2026-08-12T19:55:33.35+00:00

I've just re-checked /files in eastus2 - it worked earlier when I wrote this message, but now has the same broken behaviour as swedencentral - so, the issue has now spread to eastus2.

I've also tested skills as requested in eastus2 - no joy.

GET https://eastus2-foundry.services.ai.azure.com/anthropic/v1/skills HTTP/1.1 404 Not Found Content-Length: 117 Content-Type: application/json x-should-retry: false request-id: req_011CdyRYPfZbgLEettMXTFAp x-robots-tag: none azureml-served-by-cluster: hyena-eastus2-02 apim-request-id: 54a3f666-c5ca-44e0-95a6-0ddbf128e5cd Strict-Transport-Security: max-age=31536000; includeSubDomains; preload x-content-type-options: nosniff x-ms-region: East US 2 Date: Wed, 12 Aug 2026 19:41:35 GMT {"type":"error","error":{"type":"not_found_error","message":"Not found"},"request_id":"req_011CdyRYPfZbgLEettMXTFAp"}

Answer 1

Allan Solomon Mejia 10,385

Hello @Glen Anderson and @Kienan McLellan

Based on the additional testing in this thread, this now looks like a service-side regression affecting the Anthropic API integration in Microsoft Foundry, rather than an issue specific to your resource or Sweden Central.

The strongest indicators are:

/anthropic/v1/files previously worked and began returning 404.
The same behavior has now been reproduced in East US 2.
/anthropic/v1/skills has also started failing.
Existing skill IDs can still be used, suggesting the underlying model deployment itself remains functional.

Microsoft’s current Foundry documentation explicitly lists both the Files API and Skills API as supported Claude API surfaces, so a 404 Not Found from these routes shouldn't be treated as expected behavior.

Since the issue has now appeared across multiple regions and tenants, I wouldn't recommend recreating deployments, changing authentication, or modifying endpoint URLs as a workaround.

Please preserve the request-id, apim-request-id, UTC timestamp, region, and affected endpoint from each failure.

At this point, I recommend that a Microsoft moderator help escalate this to the Microsoft Foundry/Anthropic engineering team to check for a routing or API gateway regression affecting the Files and Skills endpoints.

The fact that East US 2 was working earlier and subsequently began returning the same errors should be particularly useful for engineering when correlating the start of the incident.

Please "Accept the Answer" if this information helped you. This will help us and others in the community as well.

Kienan McLellan 15 Reputation points

2026-08-12T20:56:58.03+00:00

Thanks Allan. It seems to have come back so not sure if someone rolled back changes. @Glen Anderson it's at least working on US East 2 now not sure about Sweden.
Allan Solomon Mejia 10,385 Reputation points

2026-08-12T21:05:53.54+00:00

Hi @Kienan McLellan

I'll call out a moderator to better assist you.

Hello Pilladi Padma Sai Manisha, can you please assist Kienan and Glen on this? Thank you.

Glen Anderson 25

Thanks @Allan Solomon Mejia -

Update:

Both endpoints worked again this morning in eastus2 and swedencentral - issue appeared resolved
Both endpoints are not working again in both eastus2 and swedencentral - issue currently persists

@Kienan McLellan would be interesting if you can confirm not working for you at the moment

swedencentral request:

HTTP/1.1 404 Not Found
Content-Length: 117
Content-Type: application/json
x-should-retry: false
request-id: req_011CdznBUkXBxDg9T9eNpaNa
x-robots-tag: none
azureml-served-by-cluster: hyena-swedencentral-02
apim-request-id: 1731eb9e-d681-4804-aa51-628fcf658c9a
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
x-content-type-options: nosniff
x-ms-region: Sweden Central
Date: Thu, 13 Aug 2026 12:52:51 GMT

{"type":"error","error":{"type":"not_found_error","message":"Not found"},"request_id":"req_011CdznBUkXBxDg9T9eNpaNa"}

eastus2 request:

HTTP/1.1 404 Not Found
Content-Length: 117
Content-Type: application/json
x-should-retry: false
request-id: req_011CdznJZ7u1dJV2TR9GZnGB
x-robots-tag: none
azureml-served-by-cluster: hyena-eastus2-01
apim-request-id: dd5b3518-163a-4b4b-9b4a-d3bafa84b17d
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
x-content-type-options: nosniff
x-ms-region: East US 2
Date: Thu, 13 Aug 2026 12:54:26 GMT

{"type":"error","error":{"type":"not_found_error","message":"Not found"},"request_id":"req_011CdznJZ7u1dJV2TR9GZnGB"}

Kienan McLellan 15 Reputation points

2026-08-13T13:32:02.9466667+00:00

Confirmed that issue is back again.
Kienan McLellan 15 Reputation points

2026-08-13T18:58:16.3066667+00:00

/skills endpoint is operational again as of an hour ago. However I will hold on as this same thing happened earlier in the day.
Allan Solomon Mejia 10,385 Reputation points

2026-08-13T19:36:34.71+00:00

Hello @Glen Anderson and @Kienan McLellan

Please let me know if you need any further assistance. Otherwise, if the information provided has resolved your issue, please consider clicking “Accept Answer” to help others who may encounter the same problem.

Thank you!
Kienan McLellan 15 Reputation points

2026-08-13T19:39:56.7766667+00:00

The information hasn't resolved it but I'll wait until this is consistently up for at least a couple days before I consider it resolved.
Allan Solomon Mejia 10,385 Reputation points

2026-08-13T19:43:36.26+00:00

Sure @Kienan McLellan .