# Glossary

The handler code within the subgraph project utilizes predefined interfaces and type utilities, which are imported from the `@blockflow-labs/utils` library. This library is pre-installed when you set up your project using the Blockflow CLI, ensuring consistent and maintainable type definitions across your codebase.

* IEventContext
* IFunctionContext
* ILog
* ITransaction
* IBlock

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### Purpose

These predefined interfaces and type utilities serve several purposes:

1. **Type Safety**: They provide a standardized and strongly-typed structure for working with blockchain data, ensuring type safety and catching potential errors during development.
2. **Code Reusability**: By using shared interfaces and types, developers can write reusable code that adheres to consistent data structures, promoting code maintainability and collaboration within teams.
3. **Integration with Subgraph Schema**: The interfaces and types are designed to align with the subgraph's schema, facilitating seamless mapping and transformation of blockchain data into the desired database entities.
4. **Documentation and Clarity**: Well-defined interfaces and types act as self-documenting code, improving code readability and making it easier for developers to understand and work with the blockchain data structures.