Every flow execution maintains data in four organized namespaces. This data flows between nodes, gets updated by user interactions, and drives flow logic.

​
Data structure

vars namespace - User-defined variables
  • Read/write access
  • Store custom data, user responses, API results
  • Persists throughout flow execution
system namespace - System-managed data
  • Read-only access
  • Flow metadata, timing, execution details
  • Automatically maintained by the platform
context namespace - Contextual information
  • Mostly read-only (set at flow start)
  • Channel info, user details, trigger context
  • Provides execution environment details
metadata namespace - Request metadata
  • Read-only access
  • API request details, timestamps, caller info
  • Available for API-triggered flows

​
Initial data

WhatsApp trigger flow starts with: 
# System variables
{{system.trigger_type}}                # "inbound_message"
{{system.flow_id}}                     # Flow UUID
{{system.started_at}}                  # ISO timestamp

# Context variables  
{{context.phone_number}}               # "+1234567890"
{{context.channel}}                    # "whatsapp"
{{context.conversation_id}}            # WhatsApp conversation ID

# Flow variables
{{last_user_input}}                    # Initial message content
API trigger flow starts with: 
# System variables
{{system.trigger_type}}                # "api_call"
{{system.tracking_id}}                # Unique execution ID
{{system.api_key_id}}                 # API key used

# Context variables
{{context.phone_number}}              # From request
{{context.channel}}                   # "api"

# Custom variables (from API request)
{{your_variable}}                     # From variables object
{{another_variable}}                  # From variables object

# Metadata
{{metadata.request_ip}}               # Caller IP
{{metadata.request_timestamp}}        # Request time

​
Accessing variables

In messages and templates: 
# Direct access (looks in vars namespace)
SendTextNode(message="Hello {{customer_name}}")

# Explicit namespace access
SendTextNode(message="Your number is {{context.phone_number}}")
SendTextNode(message="Flow started at {{system.started_at}}")
In AI fields: 
# Use same pattern in AI prompts
SendTextNode(
    message=AIField(prompt=
        "Generate greeting for {{customer_name}} who ordered {{product_name}}"
    )
)
In agent nodes: 
# Agents can read all variables through context
# Use get_variable and save_variable tools

​
Modifying variables

Wait for response node: 
# Automatically sets last_user_input when user responds
WaitForResponseNode(id="get_name")
# After user responds: {{last_user_input}} contains their message
Function node: 
# Save function response to variable
FunctionNode(
    id="calculate_score",
    function_id="score_calculator",
    save_response_to="user_score"  # Sets {{user_score}}
)

# Function can also return vars object to set multiple variables
# Function returns: {"vars": {"score": 85, "tier": "gold"}}
# Sets: {{score}} and {{tier}}
Webhook node: 
# Save API response to variable
WebhookNode(
    id="get_user_data",
    url="https://api.example.com/users/{{user_id}}",
    save_response_to="user_profile"  # Sets {{user_profile}}
)
Agent node: 
# Agent can read and write variables using tools
AgentNode(
    id="data_collector",
    system_prompt="Collect user information and save it using save_variable tool"
)
# Agent uses: save_variable(key="user_age", value="25")
# Sets: {{user_age}}

​
Data flow between nodes

Send nodes (SendTextNode, SendTemplateNode, SendInteractiveNode)
  • Read: All variables for message content and parameters
  • Write: Nothing
Wait for response node
  • Read: Nothing (just waits)
  • Write: Sets {{last_user_input}} when user responds
Decide node
  • Read: All variables to evaluate conditions
  • Write: Nothing (just routes flow)
Function node
  • Read: Sends entire execution context to function
  • Write: Can set variables via save_response_to or function return
Agent node
  • Read: Full access to all variables via get_variable tool
  • Write: Can set any variable via save_variable tool
Handoff node
  • Read: Nothing
  • Write: Nothing (just stops execution)

​
Examples

Collecting user information: 
# Ask for name
SendTextNode(id="ask_name", message="What's your name?")
WaitForResponseNode(id="get_name")
# Now {{last_user_input}} contains the name

# Ask for age  
SendTextNode(id="ask_age", message="Thanks {{last_user_input}}! What's your age?")
WaitForResponseNode(id="get_age") 
# Agent could save this as {{user_age}}
Processing and using data: 
# Function processes user input
FunctionNode(
    id="validate_age",
    function_id="age_validator", 
    save_response_to="validation_result"
)

# Conditional response based on result
DecideNode(
    id="check_valid",
    conditions=[
        Condition(label="valid", description="Age is valid"),
        Condition(label="invalid", description="Age is invalid")
    ]
)

# Different responses
SendTextNode(
    id="valid_response",
    message="Great! You're {{last_user_input}} years old."
)

SendTextNode(
    id="invalid_response", 
    message="That doesn't look like a valid age. Please try again."
)
Using API data: 
# API trigger provides order_id
# {{order_id}} available from start

# Get order details
FunctionNode(
    id="get_order",
    function_id="order_lookup",
    save_response_to="order_details"
)

# Send confirmation with order data
SendTextNode(
    id="confirmation",
    message="Order {{order_id}} for ${{order_details.total}} has been confirmed!"
)

​
Variable naming

  • Use lowercase with underscores: user_name, order_total
  • Be descriptive: last_user_input not input
  • Avoid system reserved names: flow_id, started_at