Yes. Mixpanel accepts arbitrary JSON as event properties, including objects and lists of objects, with some limits and UI caveats. Objects are supported mainly in core reports; keys aren’t indexed in Lexicon, and there are size/structure limits (e.g., event property size up to 8 KB, max 255 keys per nested object with limited nesting). [Events FAQ; Property types]
For lists of objects (e.g., a cart array), Mixpanel supports them with limits (event property up to 8 KB; 20 objects per list for projects under 100M events/month, otherwise first 5). They can be used in filters/breakdowns and support computations like size, sum, and distinct count. [List of objects; List of objects support]
