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@@dynamic

The @@dynamic attribute allows runtime modification of fields or values.

Dynamic Classes​

class MyClass {
    property1 string
    property2 int?

    @@dynamic  // allows adding fields at runtime
}

Dynamic Enums​

enum MyEnum {
    Value1
    Value2

    @@dynamic  // allows modifying values at runtime
}

Using TypeBuilder​

Modify dynamic types at runtime using TypeBuilder.

from baml_client.type_builder import TypeBuilder
from baml_client import b

async def run():
    tb = TypeBuilder()
    tb.MyClass.add_property('email', tb.string())
    tb.MyClass.add_property('address', tb.string()).description("User's address")

    res = await b.DynamicUserCreator("some user info", { "tb": tb })
    # res can now have email and address fields
    print(res)

Testing Dynamic Types​

Use type_builder and dynamic blocks in tests:

test DynamicTest {
    functions [ProcessDynamic]
    type_builder {
        class NewType {
            field1 string
        }
        dynamic class ExistingDynamicType {
            new_prop NewType
        }
    }
    args {
        input "test data"
    }
}

Use Cases​

  • Add fields based on runtime configuration
  • Support user-defined schemas
  • A/B test different output structures
  • Customize enums based on context

See Also​