I've always needed a way of serializing animated and/or static values out of Maya and so I thought I would provide one of my tools to do just that.
These are the options that is supported:
• Serialize all objects in the scene or only the passed objects.
• Serialize all attributes on those objects or only the passed attributes if they exist on the objects.
• Serialize all attribute types or only the passed attribute types.
• Serialize all values or only values that are keyed.
As noted in my GitLab description, I use my own json formatter to save this out. I might write another one to post on here eventually.