How can I get the remaining quota in APIM when quota-by-key policy in used?

Question

How can I get the remaining quota in APIM when quota-by-key policy in used?

See, Yi Xuan 5

I am using Azure APIM for the quota-by-key control. However I couldn't get the remaining quotas return so that the user aware and control the usage in a better way.
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I planned to have the remaining quotas return as a header in the outbound section.
I noticed that there is a key remaining-calls-header-name for rate-limit-by-key however it doesn't works for quota-by-key.
Please help me on that.

Ranashekar Guda 2,905 Reputation points Moderator

2025-04-07T17:03:19.44+00:00

Hello @See, Yi Xuan,

To get the remaining quota in Azure API Management (APIM) when using the quota-by-key policy, you can extend the policy to expose the remaining quota information in the response headers. It is important to note that the remaining-calls-header-name property is specifically for the rate-limit-by-key policy and does not apply to the quota-by-key policy.

Currently, the documentation does not provide a direct method to expose remaining quotas for the quota-by-key policy in the same way as for rate-limit-by-key. You may need to implement a custom solution to track and return the remaining quota based on your application's logic.

Kindly refer below link:

https://learn.microsoft.com/en-us/azure/api-management/api-management-sample-flexible-throttling#custom-key-based-throttling

I hope this helps resolve your issue. Feel free to reach out if you have further concerns.
See, Yi Xuan 5 Reputation points

2025-04-08T05:00:32.04+00:00

Hi @Ranashekar Guda do you have any example to extend the policy? I tried to understand how to do that from the link but I do not have any idea about that.
Ranashekar Guda 2,905 Reputation points Moderator

2025-04-10T10:29:19.3533333+00:00

Hi @See, Yi Xuan,

Just checking in to see if above information was helpful. If you have any further updates on this issue, please feel free to post back.
See, Yi Xuan 5 Reputation points

2025-04-10T10:33:09.79+00:00

Hi @Ranashekar Guda , I just tested the Quota Rest API and it work like a charm!

Thank you so much for the hint!

1 answer

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Ranashekar Guda 2,905 Reputation points Moderator

2025-04-07T17:03:19.44+00:00

Hello @See, Yi Xuan,

To get the remaining quota in Azure API Management (APIM) when using the quota-by-key policy, you can extend the policy to expose the remaining quota information in the response headers. It is important to note that the remaining-calls-header-name property is specifically for the rate-limit-by-key policy and does not apply to the quota-by-key policy.

Currently, the documentation does not provide a direct method to expose remaining quotas for the quota-by-key policy in the same way as for rate-limit-by-key. You may need to implement a custom solution to track and return the remaining quota based on your application's logic.

Kindly refer below link:

https://learn.microsoft.com/en-us/azure/api-management/api-management-sample-flexible-throttling#custom-key-based-throttling

I hope this helps resolve your issue. Feel free to reach out if you have further concerns.
See, Yi Xuan 5 Reputation points

2025-04-08T05:00:32.04+00:00

Hi @Ranashekar Guda do you have any example to extend the policy? I tried to understand how to do that from the link but I do not have any idea about that.
Ranashekar Guda 2,905 Reputation points Moderator

2025-04-10T10:29:19.3533333+00:00

Hi @See, Yi Xuan,

Just checking in to see if above information was helpful. If you have any further updates on this issue, please feel free to post back.
See, Yi Xuan 5 Reputation points

2025-04-10T10:33:09.79+00:00

Hi @Ranashekar Guda , I just tested the Quota Rest API and it work like a charm!

Thank you so much for the hint!

Answer 1

Ranashekar Guda 2,905 Moderator

Hello @See, Yi Xuan,

As mentioned above APIM doesn't allow you to directly add remaining quota in the response header via the quota-by-key policy, you can use the Quota REST API to retrieve this information and incorporate it into your API’s response by calling the API from your backend systems or custom policies. This provides an effective workaround for tracking quota usage and returning it to users.
Also, for your better understanding,

Ranashekar Guda 2,905 Reputation points Moderator

2025-04-10T10:50:34.0166667+00:00

Hello @See, Yi Xuan,
If you found the response helpful, please click Accept Answer and Yes for the provided answer. This will help other community members with similar issues find the solution more easily.

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How can I get the remaining quota in APIM when quota-by-key policy in used?

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