Variables

Variable scopes

Sequor supports four variable scopes, organized in a hierarchy. Each child scope can override variables with the same name from parent scopes.

Variable scopes:

Environment variables - Defined in Sequor environments by the user and typically used for credentials or environments-specific parameters (e.g. database connection strings or directory paths). These are constants that cannot be modified during flow execution. For information on defining environment variables, see Environments
Project variables - Set by operations (e.g. set_variable or http_request) during flow execution. These are persistent variables that survive between flow executions.
Source variables - Defined the variables section of http type sources and can be referenced from http_request operations using that source. These variables do not survive beyond the operation’s execution.
Local variables - Set by the same operations as project variables but with scope: local. These are temporary variables that do not survive flow execution.

Variable types

Variables can be of any Python type. The type is determined by:

When setting variables using return { "variables": ... } (for example, in an http_request operation), the variable type matches the Python value’s type.
When using the set_variable operation, the variable value is always stored as a string.

Setting variables in operations

There are two syntax formats for setting variables in operations:

Compact form - Variable value is defined as a simple string. This automatically sets the variable in the project scope.
```
"var1": "value1"
```
Extended form - Variable value is defined as a YAML object with value and scope keys. The scope can be either local or project.
```
"var2": {
  "value": "value2",
  "scope": "local"
}
```

The following examples demonstrate setting project and local variables using set_variable and http_operations operations:


steps:
  - op: set_variable
    set:
      "var1": "value1" # Project scope variable (compact form) - persists after flow execution
      "var2": { # Local scope variable (extended form) - temporary during flow execution
        value: "value2",
        scope: "local"
      },
      "var3": { # Project scope variable (extended form) - persists after flow execution
        value: "value3",
        scope: "project"
      }
  - op: http_request
    id: get_customers
    request:
      source: "bigcommerce_rest"
      url: "https://api.bigcommerce.com/stores/{{ var('store_hash') }}/{{ var('api_version') }}/customers"
      method: GET
      parameters_expression: |
        def evaluate(context):
          return {
            "limit": 5, # intentionally small limit for testing; use 100 or even 1000 for production
            "page": context.var("next_page") if context.is_var_defined("next_page") else 1
          }
      headers:
        "Accept": "application/json"
    response:
      parser_expression: |
        def evaluate(context, response):
          if response.status_code != 200:
            raise Exception("Error response code: " + str(response.status_code) + "; body: " + response.text)
          json_data = response.json()
          current_page = json_data["meta"]["pagination"]["current_page"]; # integer
          total_pages = json_data["meta"]["pagination"]["total_pages"]; # integer
          return {
            "variables": {
              "next_page": { Local scope variable (extended form) - temporary during flow execution
                "value": current_page + 1,
                "scope": "local"
              }
            },
            "tables": [{  
              "source": "stage",
              "table": "bc_customers",
              "data": json_data['data'],  
              "model": {
                "columns": [
                {"name": "id", "type": "text"},
                {"name": "first_name", "type": "text"},
                {"name": "last_name", "type": "text"}
                ]
              }
            }],
            "while": current_page < total_pages
          }```