Problem this solves: Teams forget that on Sui, storage costs are upfront and refundable on deletion. This leads to bloated designs and high fees.

What you’ll learn:

How storage fees are calculated

What rebates are and when you get them

Lifecycle management of on-chain data

Patterns for pruning and archiving

1. Upfront storage fee model

When you create or grow an object, you pay a one-time fee proportional to the size increase. When you delete an object, you receive a storage rebate (a percentage of the original fee).

2. Why it matters

Large or numerous objects can rack up significant costs.

Rebates incentivize garbage collection of unused state.

3. Lifecycle design

Creation: Pay full fee for bytes added.

Mutation: Pay/receive difference in size.

Deletion: Receive rebate.

4. Step-by-step: Pruning expired auctions

Store an expiry timestamp in each Auction object.

When expired, allow any actor to call close auction.

close auction transfers remaining assets, deletes Auction object.

Caller gets small incentive from storage rebate (or separate reward).

Keep event logs for history instead of retaining the full object.

Outcome: Reduced on-chain bloat, rebates recaptured.

5. Cost control patterns

Batch data into fewer, larger objects.

Use off-chain storage for big assets (IPFS, Arweave).

Leverage dynamic fields to avoid monolithic structs.