# Find user by external ID (SSO)

**URL:** <https://meta.discourse.org/t/find-user-by-external-id-sso/18330>\
**Category:** Feature\
**Created:** [31. Juli 2014 um 20:06 UTC](https://meta.discourse.org/t/find-user-by-external-id-sso/18330 "2014-07-31T20:06:26Z")\
**Posts on this page:** 1\
**Showing post:** 8

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**Author:** ![sascha](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/sascha/32/71383_2.png) [@sascha](https://meta.discourse.org/u/sascha)\
**Post date:** [28. April 2017 um 03:18 UTC](https://meta.discourse.org/t/find-user-by-external-id-sso/18330/8 "2017-04-28T03:18:29Z")

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We may have a bit of an unusual scenario but we’d like to integrate Discourse into multiple separate instances of our webapp, so effectively we have lots of IdPs and only one single Discourse instance.

These users have different external\_ids but the same email address. Discourse will look up users by external\_id and if not found will look them up by the email address and update the external\_id if found.

This effectively makes discourse merge our external users, which is very nice, making the email address the only unique identifier as the external\_id in discourse changes. To fetch notifications we’d like to look up a user by the external email address as the external\_id does not necessarily match any more.

Is this possible?

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_[View the full topic](https://meta.discourse.org/t/find-user-by-external-id-sso/18330)._