# ESI API - some responses give a X-Expires header which lies in the past

**URL:** <https://forums.eveonline.com/t/esi-api-some-responses-give-a-x-expires-header-which-lies-in-the-past/36721>\
**Category:** Third Party Developers\
**Created:** [November 5, 2017, 2:44pm UTC](https://forums.eveonline.com/t/esi-api-some-responses-give-a-x-expires-header-which-lies-in-the-past/36721 "2017-11-05T14:44:36Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Spyke\_Austrene](https://sea1.discourse-cdn.com/eveonline/user_avatar/forums.eveonline.com/spyke_austrene/32/448706_2.png) [@Spyke\_Austrene](https://forums.eveonline.com/u/Spyke_Austrene)\
**Post date:** [November 5, 2017, 2:44pm UTC](https://forums.eveonline.com/t/esi-api-some-responses-give-a-x-expires-header-which-lies-in-the-past/36721/1 "2017-11-05T14:44:36Z")

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Hi guys,

Responding with an already passed date in the expired header (earlier than the Date header value) makes no sense and would be a sign of some sort of misconfiguration.

My client would treat such response as “already expired” and not cache it, thus spamming your ESI service with requests.

Of course, I could always hard-code a proper cache time, but as you rely on caching much instead of rate-limiting (which i really find great you do), you need 3rd party devs to use the caching mechanisms, but they won’t if they dont work for them.

It happens most frequently with Universe routes - Systems, Stargates and so on

See that Screenshot, for example, was made with that request  
[https://esi.tech.ccp.is/latest/universe/systems/30000733/?datasource=tranquility](https://esi.tech.ccp.is/latest/universe/systems/30000733/?datasource=tranquility)

> **[Response Header](https://ibb.co/cbwVfw)**
>
> Image Response Header hosted in imgbb.com

thanks,  
cya,  
Mike

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**Author:** ![Blacksmoke16](https://sea1.discourse-cdn.com/eveonline/user_avatar/forums.eveonline.com/blacksmoke16/32/376589_2.png) [@Blacksmoke16](https://forums.eveonline.com/u/Blacksmoke16)\
**Post date:** [November 5, 2017, 3:42pm UTC](https://forums.eveonline.com/t/esi-api-some-responses-give-a-x-expires-header-which-lies-in-the-past/36721/2 "2017-11-05T15:42:23Z")

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See if this issue is already posted on [https://github.com/ccpgames/esi-issues/issues](https://github.com/ccpgames/esi-issues/issues). If not create an issue for it.

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**Author:** ![Spyke\_Austrene](https://sea1.discourse-cdn.com/eveonline/user_avatar/forums.eveonline.com/spyke_austrene/32/448706_2.png) [@Spyke\_Austrene](https://forums.eveonline.com/u/Spyke_Austrene)\
**Post date:** [November 5, 2017, 4:01pm UTC](https://forums.eveonline.com/t/esi-api-some-responses-give-a-x-expires-header-which-lies-in-the-past/36721/3 "2017-11-05T16:01:44Z")

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Thats what i did, thanks

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**Author:** ![system](https://global.discourse-cdn.com/eveonline/original/3X/4/1/41ec4921cbaca7a6f9ea556e7cc20018461eae5e.png) [@system](https://forums.eveonline.com/u/system)\
**Post date:** [February 3, 2018, 4:01pm UTC](https://forums.eveonline.com/t/esi-api-some-responses-give-a-x-expires-header-which-lies-in-the-past/36721/4 "2018-02-03T16:01:50Z")

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