I’m working on a Flow blockchain project and need to maintain ownership records for NFTs within my Cadence contract itself. A developer recommended using event aggregation with an external database, but I want to avoid that approach if possible. I prefer keeping all ownership information stored directly in the smart contract rather than relying on off-chain solutions. What are some effective methods to track which account owns each NFT token directly within the contract code? Are there any built-in Cadence features or common patterns that work well for this use case? I’m looking for approaches that don’t require external infrastructure while still being efficient and reliable.
This is really interesting! I’ve been diving into Cadence lately too, and ownership tracking is crucial for NFT projects.
Have you considered using Cadence’s built-in resource model? NFTs in Flow are resources that live directly in users’ accounts - not tracked in a central mapping like Ethereum. The “ownership” is basically wherever the resource exists.
Maybe you’re looking for something different though? Are you trying to maintain a separate ownership registry for querying, or does your contract need to track ownership for specific business logic?
What’s your main concern with the off-chain approach the other dev suggested? Is it the complexity of maintaining external infrastructure, or something else? Your specific use case would help people give better advice.
I’m still learning Cadence myself, so I’m genuinely curious about your approach - sounds like you’re building something pretty cool!
cadence’s resource ownership model is solid - no duplication or loss issues. if you need centralized tracking, try account storage with a dictionary mapping token IDs to addresses. just watch those storage costs on flow - they add up fast.
Yes, that’s the common practice in Flow, but you might consider integrating a centralized registry directly into your contract’s storage using a mapping dictionary. This method is ideal for marketplace contracts that require ownership queries without accessing individual accounts. You can map token IDs to owner addresses and update the registry whenever transfers occur through your contract functions. It’s crucial to ensure that all transfers utilize your contract methods to keep the mapping updated. However, be cautious about storage costs, as large mappings in Flow can become expensive, which may lead you to adopt a hybrid model for tracking ownership.