Interfaces Overview

Interfaces define how managers store or compute data. They encapsulate persistence logic, conversion between Django models and managers, and the inputs required to instantiate a manager.

GeneralManager ships with four main interface flavours:

• Database interfaces persist records to relational databases.
• Existing model interfaces wrap legacy Django models without generating new tables.
• Read-only interfaces synchronise static datasets from JSON.
• Calculation interfaces compute values on the fly from inputs and related managers.
• Request interfaces connect managers to remote HTTP-style services through declarative request operations and filter mappings.

All interfaces inherit from general_manager.interface.base_interface.InterfaceBase, which provides shared behaviour such as identification, validation, and integration with the dependency tracker.

Understanding the capabilities of each interface helps you pick the right tool for each domain object.

Module layout

The interface layer is now organised by responsibility:

• general_manager.interface.interfaces contains the concrete interface classes (also re-exported via general_manager.interface for convenience).
• general_manager.interface.bundles defines reusable capability sets such as ORM_WRITABLE_CAPABILITIES and READ_ONLY_CAPABILITIES.
• general_manager.interface.capabilities holds the capability implementations (grouped into subpackages like orm/, read_only/, and calculation/) plus utilities under capabilities/orm_utils.
• general_manager.interface.manifests owns the manifest + builder pipeline that wires capabilities onto interfaces.
• general_manager.interface.utils hosts shared plumbing such as the ORM base models, protocol definitions, and error helpers, while general_manager.interface.infrastructure implements the startup-hook and system-check registries.

Capability-first interfaces

Interfaces now operate in a capability-first mode. Each class declares the capabilities it needs, and the manifest/builder pipeline wires those capabilities at runtime. Read the dedicated guide in capability-first interfaces and see the how-to articles on creating custom interface types and custom capabilities for step-by-step instructions.