# Adding an arbitrary custom\_field with a specified type to a plugin
**URL:** https://meta.discourse.org/t/adding-an-arbitrary-custom-field-with-a-specified-type-to-a-plugin/52977
**Category:** Development
**Created:** [November 15, 2016, 11:50pm UTC](https://meta.discourse.org/t/adding-an-arbitrary-custom-field-with-a-specified-type-to-a-plugin/52977 "2016-11-15T23:50:53Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@jgujgu](https://meta.discourse.org/u/jgujgu)
#### Post date: [November 15, 2016, 11:50pm UTC](https://meta.discourse.org/t/adding-an-arbitrary-custom-field-with-a-specified-type-to-a-plugin/52977/1 "2016-11-15T23:50:53Z")
Hi @joebuhlig. I hope to make a plugin that extends what types of attributes models, like `Topic`, have, and I noticed you have a reasonable `custom_field` called `vote_count` added to the Topic model…
I’m familiar with Rails and expected a migration or a least a type declaration for `vote_count` somewhere (I did search the repo for `vote_count`, and only saw it in code/templating). Moreover, all the discussion on Discourse meta pertains to `custom_fields` for `Users`, not really `custom_fields` in general. Is there a how-to guide on adding an arbitrary `custom_field` with a specified type to a plugin that you might point me to?
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### Author:  [@joebuhlig](https://meta.discourse.org/u/joebuhlig)
#### Post date: [November 16, 2016, 5:45pm UTC](https://meta.discourse.org/t/adding-an-arbitrary-custom-field-with-a-specified-type-to-a-plugin/52977/2 "2016-11-16T17:45:33Z")
That’s not exactly an arbitrary custom field. It’s a custom field on the Topic. You can do the same for a Category and User. I can’t say that I remember seeing any docs on it. I simply saw the ability when running through the master codebase. That’s how I determine most of the possibilities. It would be tough for the team to manage that level of documentation on something moving so fast.
That said, if you look through the Topic model extension I did, you can see the use of custom fields on all three.
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### Author:  [@jgujgu](https://meta.discourse.org/u/jgujgu)
#### Post date: [November 17, 2016, 1:11am UTC](https://meta.discourse.org/t/adding-an-arbitrary-custom-field-with-a-specified-type-to-a-plugin/52977/3 "2016-11-17T01:11:59Z")
@joebuhlig thank you for clarifying your M.O…I just have one quick last question.
I’m still a little confused as to how a `custom_field`’s type gets set in the database. In [this plugin](https://github.com/xfalcox/discourse-signatures/blob/master/plugin.rb#L15), I clearly see where the typing is set, with `register_custom_field_type()`. Why does your plugin and a few others I’ve looked at not have to use this particular method?
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### Author:  [@jgujgu](https://meta.discourse.org/u/jgujgu)
#### Post date: [November 17, 2016, 1:15am UTC](https://meta.discourse.org/t/adding-an-arbitrary-custom-field-with-a-specified-type-to-a-plugin/52977/4 "2016-11-17T01:15:45Z")
The custom\_field spec tests make it apparent that its flexible for typing, but I guess both ways are just fine.
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### Author:  [@joebuhlig](https://meta.discourse.org/u/joebuhlig)
#### Post date: [November 17, 2016, 1:10pm UTC](https://meta.discourse.org/t/adding-an-arbitrary-custom-field-with-a-specified-type-to-a-plugin/52977/5 "2016-11-17T13:10:55Z")
And that’s how I would discover it as well. 😉