Where should I put DTO conversions in our cargo workspace?

Question

I have a workspace with many microservices and many times I want to perform conversions between the DTOs of different services (e.g. convert the response of one service into a request for another). I'm having a hard time deciding where to put these conversions due to cargo rejecting cyclic dependencies. Some solutions I've thought of:

• Decide on a convention such that conversions from crate A to crate B (A->B) belong in crate A (always the 'from' side). This means crate A depends on crate B but this precludes crate B from depending on A if it ever calls A directly (which actually happens in our codebase)
• Create a separate convert crate where we store conversions, gated by both features for both involved crates. This means convert depends on both A and B so neither can use these conversions directly or otherwise that would be a cylic dependency!

I'll take any ideas to solve this cleanly