# JSon fields API contatcs

**URL:** <https://community.hubspot.com/t/json-fields-api-contatcs/11234>\
**Category:** APIs & Integrations\
**Tags:** contacts\
**Created:** [October 18, 2018, 3:03pm UTC](https://community.hubspot.com/t/json-fields-api-contatcs/11234 "2018-10-18T15:03:28Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![system](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/system/32/124_2.png) [@system](https://community.hubspot.com/u/system)\
**Post date:** [October 18, 2018, 3:03pm UTC](https://community.hubspot.com/t/json-fields-api-contatcs/11234/1 "2018-10-18T15:03:28Z")

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what are the json field to set birth date and gender?

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**Author:** ![IsaacTakushi](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/isaactakushi/32/70387_2.png) [@IsaacTakushi](https://community.hubspot.com/u/IsaacTakushi)\
**Post date:** [October 19, 2018, 3:06pm UTC](https://community.hubspot.com/t/json-fields-api-contatcs/11234/2 "2018-10-19T15:06:16Z")

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Hi [@Carlo\_Narcisi](https://community.hubspot.com/u/carlo_narcisi),

Those are not [default contact properties](https://knowledge.hubspot.com/articles/kcs_article/contacts/list-of-hubspot-s-default-contact-properties) in HubSpot, so you will have to [create custom contact properties](https://knowledge.hubspot.com/articles/kcs_article/contacts/how-can-i-create-a-custom-property) to store those values before you can set them with [this](https://developers.hubspot.com/docs/methods/contacts/update_contact) and the other “update” endpoints.

If you have already created these properties, please send me links to them in your portal.