Feature Suggestion: Custom Cluster Nodes with User-Defined Sub-Nodes (Non-AI)

Hi everyone,

I find the custom node functionality in callin.io to be an excellent feature. Building on this, I'd like to suggest an enhancement: the capability to create custom cluster nodes that can include user-defined sub-nodes, going beyond the current AI-specific sub-node capabilities.

As I understand it, creating the main custom cluster node itself isn't the main hurdle. The challenge appears to be in defining and using custom (i.e., non-AI) nodes as sub-nodes. My current understanding is that only AI-related nodes can be utilized as sub-nodes in the existing setup.

I imagine a configuration for the custom sub-node connection within a node's class that might resemble this:

inputs: [
    {
        type: NodeConnectionType.Main,
        displayName: "Input",
    },
    {
        displayName: "YourCustomSubNode",
        type: NodeConnectionType.SubNode,
        maxConnections: 1,
    },
    // Additional sub-node connections could go here
]

Based on my review of the callin.io source code, I suspect that retrieving data from such a custom sub-node within the cluster node could potentially be managed like this:

const subNodeData = await this.getInputConnectionData(NodeConnectionType.SubNode, 1);

This would presumably then invoke the supplyData (or equivalent execution method) implementation within the connected sub-node's class.

Enabling the creation of cluster nodes with various, user-defined sub-nodes would be immensely beneficial. It would greatly improve the organization of complex workflows, make them more modular, and enhance overall readability and maintainability.

What are your thoughts on this potential feature?