# isAuthorized Expression \[error\] Unknown function

**URL:** <https://forum.inductiveautomation.com/t/isauthorized-expression-error-unknown-function/44731>\
**Category:** Ignition\
**Created:** [March 21, 2021, 11:21pm UTC](https://forum.inductiveautomation.com/t/isauthorized-expression-error-unknown-function/44731 "2021-03-21T23:21:31Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![sbeauregard66](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@sbeauregard66](https://forum.inductiveautomation.com/u/sbeauregard66)\
**Post date:** [March 21, 2021, 11:21pm UTC](https://forum.inductiveautomation.com/t/isauthorized-expression-error-unknown-function/44731/1 "2021-03-21T23:21:31Z")

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Hi there.

I am bumping this topic again as I can find no resolution.

I have tried to use isAuthorized in an expression as stated can be done as of 8.0.2  
[https://docs.inductiveautomation.com/display/DOC80/isAuthorized](https://docs.inductiveautomation.com/display/DOC80/isAuthorized)

I am using 8.1.3 and this function does not even exist in the expression menus. The only thing listed under the Users category is hasRole.

If I try to use isAuthorized in an expression it errors as unknown function.

![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/1/913abdfe7afce6415803f3d3065d62e8b52e32a2.png)

This previous post is the exact same problem.

> [@\[error\] Unknown function :'IsAuthorized'](http://forum.inductiveautomation.com/t/error-unknown-function-isauthorized/41911):
>
> Hi, unable to add expression “IsAuthorized” and getting below error . i tested in v8.0.16 and version 8.1 [image] the only avaiable “hasRole”

Am I missing something here?

Thanks

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**Author:** ![cmallonee](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cmallonee/32/6416_2.png) [@cmallonee](https://forum.inductiveautomation.com/u/cmallonee)\
**Post date:** [March 22, 2021, 12:38am UTC](https://forum.inductiveautomation.com/t/isauthorized-expression-error-unknown-function/44731/2 "2021-03-22T00:38:45Z")

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The scope of the `isAuthorized` expression is restricted to Perspective sessions. I don’t even think Vision projects utilize Security Levels, and as such the functions serves no purpose in the Vision context.

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**Author:** ![sbeauregard66](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@sbeauregard66](https://forum.inductiveautomation.com/u/sbeauregard66)\
**Post date:** [March 22, 2021, 1:17am UTC](https://forum.inductiveautomation.com/t/isauthorized-expression-error-unknown-function/44731/3 "2021-03-22T01:17:17Z")

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Sorry I didn’t mention that I am using this in perspective, which is why I’m confused why this is not working.

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**Author:** ![sbeauregard66](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@sbeauregard66](https://forum.inductiveautomation.com/u/sbeauregard66)\
**Post date:** [March 22, 2021, 2:03am UTC](https://forum.inductiveautomation.com/t/isauthorized-expression-error-unknown-function/44731/4 "2021-03-22T02:03:44Z")

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OK so I just figured something out. I was trying to use isAuthorized in an Expression Tag. It is not available. I guess I should have realized that since tags aren’t specific to either Vision or Perspective.  
I created an expression binding in Perspective and was able to use the isAuthorized function.  
A little ambiguous but I got it to work. I assumed an expression function was an expression function and should be able to be used in any expression.

Solved

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [March 22, 2021, 12:22pm UTC](https://forum.inductiveautomation.com/t/isauthorized-expression-error-unknown-function/44731/5 "2021-03-22T12:22:54Z")

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> [@sbeauregard66](#):
>
> A little ambiguous but I got it to work.

If you think about login security in general, and the all-the-time-regardless-of-users nature of gateway tags (all types, not just expression tags), it'll make more sense. This type of scope-dependence permeates Ignition, so you might consider it first when something doesn't work the way you assume.