Do I need a separate product feed for ChatGPT?

No, and building one usually makes things worse. Model the commercial truth once, then make each retrieval channel an output of it.

No. A channel-specific catalogue recreates the problem every time a new interface appears, and it guarantees the versions drift apart.

The stronger architecture is to model the commercial truth once, covering identity, attributes, variants, price, availability, relationships and fulfilment, then expose the appropriate version through your website, structured data, merchant feeds and supported AI integrations. Each channel becomes an output rather than a separate source.

Specifications do differ between destinations and they will keep changing. That is an argument for one well-modelled source with per-channel mappings, not for a separate catalogue per channel.