# F5 APM Variable Assign agent

**URL:** <https://community.f5.com/t/f5-apm-variable-assign-agent/75081>\
**Category:** Technical Forums\
**Tags:** application-delivery\
**Created:** [September 4, 2024, 6:26am UTC](https://community.f5.com/t/f5-apm-variable-assign-agent/75081 "2024-09-04T06:26:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Karthick1](https://avatars.discourse-cdn.com/v4/letter/k/b19c9b/32.png) [@Karthick1](https://community.f5.com/u/Karthick1)\
**Post date:** [September 4, 2024, 6:26am UTC](https://community.f5.com/t/f5-apm-variable-assign-agent/75081/1 "2024-09-04T06:26:32Z")

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Hi All,

i am unable to understand the usage of Variable assign agent on F5 APM.

is there any simple way to understand

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<div class="post-metadata">

**Author:** ![Lucas\_Thompson](https://d1p9zq3aats0t8.cloudfront.net/user_avatar/community.f5.com/lucas_thompson/32/19403_2.png) [@Lucas\_Thompson](https://community.f5.com/u/Lucas_Thompson)\
**Post date:** [September 4, 2024, 4:24pm UTC](https://community.f5.com/t/f5-apm-variable-assign-agent/75081/2 "2024-09-04T16:24:33Z")

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In simple terms, session variables are the mechanism that APM uses to store data about user’s sessions. This data has these properties:

1- It’s stored in BIG-IP’s high speed session database, which is the same one that is used to store information about [sticky load balancing](https://www.f5.com/resources/white-papers/cookies-sessions-and-persistence).

2- The data is string values that may include unicode characters. Array values are strings that are delimited by pipe | characters.

3- The names of the variables are loosely hierarchical, but do not follow any strict naming rules. You may set a session variable with any name you like. Here’s a [reference with some of the common variables used](https://techdocs.f5.com/kb/en-us/products/big-ip_apm/manuals/product/apm-config-11-4-0/apm_config_sessionvars.html).

4- Session variables are scoped per user. User sessions do not have access to each other’s session variables.

5- Session variables (usually tokens or passwords) may be encrypted in-memory so that a process dump will not contain sensitive data. The encryption key is a combination of a dynamic nonce used for that session and the BIG-IP’s master key.

The Variable Assign agent simply allows you to set one of these session variables to a custom value you choose.

Here’s a lab that talks about that VPE agent, how to use it, and why it’s there:

> **[Lab 4: Visual Policy Editor (VPE) & Session Variables](https://f5-agility-labs-iam.readthedocs.io/en/latest/class8/module4/module4.html#)**

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<div class="post-metadata">

**Author:** ![Karthick1](https://avatars.discourse-cdn.com/v4/letter/k/b19c9b/32.png) [@Karthick1](https://community.f5.com/u/Karthick1)\
**Post date:** [September 6, 2024, 1:04pm UTC](https://community.f5.com/t/f5-apm-variable-assign-agent/75081/3 "2024-09-06T13:04:54Z")

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Thank you