Basics of Business Logic in Hasura DDN
Introduction
In Hasura DDN, custom business logic is treated as a first-class citizen and like any other data source. This means, using a lambda connector, you can expose a function written in your language of choice return data from it directly to your GraphQL API.
We treat custom business logic like a data source because it allows for seamless integration into your GraphQL API, just like databases or other external services. This approach enables you as the API author to unify your data and logic, ensuring consistent access patterns, security rules, and relationships across all parts of the API.
This custom logic can be used to query or mutate data independently or to extend the functionality of existing models in your API. By connecting custom logic to other resources, you can enhance and expand the capabilities of data from different sources.
Treating custom logic as a data source simplifies your architecture, reduces duplication, and makes your APIs more flexible and maintainable.
Currently, we have lambda connectors for TypeScript, Python, and Go; these connectors and their custom functions can be hosted by Hasura or on your own infrastructure.
Functions and procedures
Regardless of which language you prefer, your connector will generate a command in your metadata for each function. These commands will be identified in your metadata as either functions — for querying data — or procedures — for modifying data — via your API.
Each connector has its own conventions for determining if the custom logic you write is identified as either a function or a procedure.
Learn more
- Learn how to add a lambda connector
- Learn how to add independent custom logic to your API
- Learn how to add custom logic to an existing model in your API
If you're curious about native queries and mutations, check out the connector-specific reference docs for generating queries and mutations using the native capabilities of your data source.
