Elsa 3.0 Proposed Enhancements and Learnings

In our journey with Elsa, we've identified several areas of improvement that can make the system more robust, modular, and developer-friendly. Here's a breakdown of our findings and proposed actions:

### 1. Refinement of Activity JSON Format

**Issue**
The current intertwining of activity input properties with other metadata complicates UI implementation.

**Proposal**
- Introduce distinct `inputs` and `outputs` fields in the JSON schema to clearly segregate activity-related properties.

### 2. Streamlining Polymorphic & Activity Serialization

**Issue**
We're using a complex custom JSON converter for the deserialization of `IActivity` and `object` instances.

**Proposal**
- Consider leveraging .NET 7 or the upcoming .NET 8 features to employ custom contract resolvers. This can optimize the built-in polymorphic serialization and deserialization processes.

### 3. Abstraction of JSON Serialization Mechanism

**Issue**
Some services expose their JSON serializer settings, which negates the intent behind abstracting serialization.

**Proposal**
- Ensure encapsulation by hiding JSON serializer settings and emphasizing a more generic serialization interface.

### 4. Overhaul of the REST API Design

**Issue**
The current REST API grew organically, resulting in inconsistent API signatures.

**Proposal**
- Initiate a comprehensive review of the current API endpoints.
- Redesign the API with a structured approach, focusing on consistency and predictability.

### 5. Evaluation of gRPC API Implementation

**Issue**
The limitations and issues in the current REST API design might find solutions in a different approach.

**Proposal**
- Investigate the feasibility and advantages of adopting an RPC style with gRPC. This might be especially beneficial for operation-driven endpoints.

### 6. Decoupling Elsa.Workflows.Api

**Issue**
The `Elsa.Workflows.Api` module tightly couples multiple modules, which goes against the modular philosophy.

**Proposal**
- Allow individual features to expose their functionality as API endpoints autonomously.
- Refactor `Elsa.Workflows.Api` to ensure true modularity in the system.

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We welcome feedback and additional insights into these proposed enhancements.