gradido/dlt-connector/README.md

DLT Connector

Overview

This implements the DLT Connector using gradido-blockchain-js as a Node module.
gradido-blockchain-js builds the native library gradido_blockchain via SWIG, making it accessible to Node.js.

Most of the Logic is handled by gradido-blockchain. The connector’s purpose is to send Gradido transactions, serialized in blockchain format, through the Hiero SDK into the Hedera Network as Topic Messages.
The gradido-node listens to these Hedera/Hiero topics, validates the transactions, and stores them efficiently.
Transactions can then be retrieved via a JSON-RPC 2.0 API from gradido-node

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Structure

The module makes extensive use of schema validation with Valibot.
All objects without internal logic are represented as Valibot schemas, with their corresponding TypeScript types inferred automatically.
Valibot allows clear separation of input and output types, reducing the need for repetitive null | undefined checks.
When a function expects an output type, TypeScript ensures that the data has been validated via parse or safeParse, guaranteeing type safety at runtime.

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src/bootstrap

Contains initialization code executed once at program startup by src/index.ts.

src/cache

Contains code for caching expensive computations or remote data.
Currently used only by KeyPairCacheManager.

src/client

Contains the client implementations for communication with
gradido-node, the backend, and the Hiero service.
Each <Name>Client class is a singleton providing:

• configuration and connection management
• API-call methods mirroring the target service
  Each client may include optional input.schema.ts and/or output.schema.ts files defining Valibot schemas for its complex data structures.

src/config

Contains the Valibot-based configuration schema, default values, and logic for parsing process.env.
If a required field is missing or invalid, the module prints an error and terminates the process.

src/data

Contains DCI (Data-Context-Interaction) Data Objects:
simple domain objects that are difficult to express as Valibot schemas, as well as Logic Objects containing core business logic.
Also includes domain enums.

src/interactions

Contains complex business logic (Interactions in DCI terms).
Each use case resides in its own subfolder with one Context Object and corresponding Role Objects.

src/schemas

Contains Valibot schemas shared across multiple parts of the program.

src/server

Contains the Elysia-based REST API used by the backend to submit new Gradido transactions.
It is intended to integrate with Valibot schemas; currently, it uses @sinclair/typebox to convert Valibot schemas to the native format expected by Elysia.

src/utils

Contains small, generic helper functions that do not clearly fit into any of the other directories.

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