Variables let agents deterministically remember information across conversation turns, track progress, and maintain context throughout the session. You define all variables in the variables block, and all subagents in the agent can access the variables.
There are several types of variables:
Define variables in the Variables block.
1CurrentState: mutable string = "gatheringInfo"
2 description: "The current state, or step, of the interview."
3 label: "State"
4 visibility: "External"Variable names must follow Salesforce developer name standards:
To reference a variable from the script, use @variables.<variable_name>.
1if @variables.Customer_Contact is None:
2 set @variables.No_Matching_Contact = TrueTo reference a variable from within reasoning instructions, use {!@variables.<variable_name>}.
1reasoning:
2 instructions: ->
3 | Always use {!@variables.Customer_Email} for the customer's email address.Custom variables have these properties:
mutable - Optional. Allows the agent to change the variable’s value. To ensure a variable’s value is never changed, define the variable without mutable.description - describes the variable. Optional. If you want the LLM to use reasoning to set the variable’s value, include a description to help the LLM set the value correctly. See Let the LLM set variables with user-entered information (slot filling).label - Optional. The variable’s name as displayed in the UI. By default, the description is generated from the name. For example, if your variable’s name is my_var, the UI displays the label My Var.visibility - Optional. Default value is Internal. Set visibility to External to allow an API to set the variable’s value, or to change the variable’s value when testing the agent in simulate mode.1variables:
2 isPremiumUser: mutable boolean = False
3 description: "Indicates whether the user is a premium user."
4 label: "Has Gold Status"
5
6 customer_loyalty_tier: mutable string = "standard"
7 description:|
8 Stores the customer's membership tier level.Custom variables can have these types:
| Type | Notes | Example |
|---|---|---|
string | Any alphanumeric string without special characters. | name: mutable string = "" |
number | Use for both integers and decimals. For example, 42 or 3.14. Compiles to IEEE 754 double-precision floating point. | age: mutable number, price: mutable number = 99.99 |
boolean | Allowed values are True or False. The value is case-sensitive, so capitalize the first letter. | is_active: mutable boolean = True |
object | Value is a complex JSON object in the form {"key": "value"}. | order_line: mutable object = {"SKU": "abc12344409","count": 42} |
date | Any valid date format. | start_date: mutable date |
id | Deprecated. Use string to store a Salesforce record ID. | See string type. |
list[type] | A list of values of the specified type. All primitive types and object type are supported. | flags: mutable list[boolean] = [True, False, True], scores: list[number] = [95, 87.5, 92], obj_list: mutable list[object] = None |
Use None to check whether a variable has a value. You can use None with any variable type. For a string variable, you can also use "" to check if the variable is set to an empty string. When checking string variables in conditional statements, you might want to use both None and "".
For more information, see Agent Script Reference: Conditional Expressions.
A linked variable’s value is tied to a source, such as an action’s output. Linked variables have these restrictions:
The source field references where the variable gets its value. Supported source namespaces are:
| Namespace | Available Properties | Description |
|---|---|---|
@MessagingSession | Id, MessagingEndUserId, EndUserLanguage | Properties of the messaging session |
@MessagingEndUser | ContactId | Properties of the messaging end user |
@VoiceCall | Id | Properties of the voice call |
1variables:
2 session_id: linked string
3 source: @MessagingSession.Id
4 description: "The messaging session ID"
5 contact_id: linked string
6 source: @MessagingEndUser.ContactId
7 description: "The contact ID of the end user"
8 voice_call_id: linked string
9 source: @VoiceCall.Id
10 description: "The voice call ID"Linked variables can have these types:
stringnumberbooleandateid (deprecated; use string for Salesforce record IDs)Agent Script provides predefined, prepopulated system variables that you can use in your agent. To access system variables, use @system_variables.<variable_name>. A system variable is:
variables blockCurrently, @system_variables.user_input is the only system variable.
The user_input system variable contains the customer’s most recent utterance (not the entire conversation history).
The LLM remembers the entire conversation history, so you don’t typically need to use @system_variables.user_input unless you’re passing the last thing a customer said into an action.
Note
In this example, we pass the last customer utterance into a sentiment analysis action. Although the agent’s LLM can also analyze sentiment, we want to use a prompt template action that understands industry-specific terminology and our customer’s rapidly-changing language patterns.
1reasoning:
2 actions:
3 AnalyzeSentiment: @actions.AnalyzeSentiment
4 with utterance = @system_variables.user_input
5 set @variables.customer_sentiment = @outputs.sentiment_classificationFor examples and patterns using variables, see Agent Script Pattern: Using Variables Effectively.
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