# Api & Custom Fields

**URL:** <https://forum.asana.com/t/api-custom-fields/1733>\
**Category:** API & Developers\
**Created:** [13 April 2017 12:42 UTC](https://forum.asana.com/t/api-custom-fields/1733 "2017-04-13T12:42:27Z")\
**Posts on this page:** 1\
**Showing post:** 4

<div class="post-metadata">

**Author:** ![James\_Ferreira](https://luna1.co/8d76cd.png) [@James\_Ferreira](https://forum.asana.com/u/James_Ferreira)\
**Post date:** [23 August 2017 20:28 UTC](https://forum.asana.com/t/api-custom-fields/1733/4 "2017-08-23T20:28:11Z")

</div>

I’m not able to update the custom fields and get “errors”:[{“message”:"custom\_fields: Value is not valid JSON:

```
{ 
  "id":392096801051329,
  "custom_fields":{
    "24321869754625":"Test", 
    "188798652655039":197365168746421 
  },
  "due_on":"2017-08-01",
  "name":"James",
}   

```

It seems to be in the format provided and If I remove the custom\_fields parameter I am able to update my task. What is missing?

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_[View the full topic](https://forum.asana.com/t/api-custom-fields/1733)._