Very well done. But I'd rather avoid the magic ("any unknown properties go into custom"). For instance, we could add or rename a property in the future, and it would clash with something a user defined.

My idea of this was providing the custom property as a box for them to put whatever they wish in. I can see the difficulty with that, though, since returning something like this:

return [
  "groupName" => "...",
  "custom" => [
    "a" => "b"
    ]
];

would overwrite the custom array. We could deep-merge it separately, but then we'd have to be sure we capture user's intent (unsetting a property, for instance). Maybe for now, we just keep it simple: add the custom property, and allow them to manipulate it directly?

public function __invoke($endpointData)
{
  $endpointData->custom['a'] = 'b';
}

A second concern of mine is wrt serializing to the Camel files and loading from them. Did you test that the custom properties were serialized to the YAML as well, and properly loaded from them (can check this with --no-extraction)?

Sounds good, I'll update tomorrow

Hi @shalvah, I've updated to modify the custom property directly. I can confirm that YAML serialization and extraction is working as expected.

3.19.0 '👍