5.1.1
2026-03-06
The backend design for Pledger.io
The REST-api is the main component of the application. This part of Pledger.io is build using the following tooling:
-
Gradle, used as the build tool.
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Micronaut framework, used as the DI and API framework.
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LangChain4j, used as the engine to interact with Vector stores and LLM implementations.
Rest design
The REST interface is designed contract-first. This means that all APIs are designed in an Open API Specification file and interfaces are generated using Micronaut.
The code is generated at compile time, and each module implements a small part of the REST interface.
Internal design
Modular design
The REST-api is designed to be a stateless application. The application is split up in several modules, where each module can depend on other modules. This is done to allow the application to be designed around a use case, like personal budgeting or small organizations.
| Module | Dependencies | Description |
|---|---|---|
Core |
- |
The base module for the entire Pledger.io application. |
Banking |
|
The module contains all logic regarding the transaction management and account management. |
Classification |
|
Contains a system to categorize things in Pledger.io. |
Budget |
|
Contains the logic allowing users to budget their spending. |
Contract |
|
Contains the logic allowing users to manage any contracts they have for spending. |
Suggestions |
|
Contains logic to suggest changes to transactions, either using pre-defined rules or AI. |
Exporter |
|
Contains the logic to import and export all information from a users account. |
Architecture of each module
Each of the modules is setup using the following layered architecture:
