Short-term blob futures, a way to buy blob space in advance
Strawmap Beyond that (Long term) · short-dated blob futures
This is a concept that lets rollups buy blob space in near-future blocks at a price fixed in advance. It aims to make blob fees, which rise and fall from block to block, predictable.
Why it is needed
Rollups batch and process transactions, then post that data to Ethereum. The dedicated storage space used for this is the blob. The blob fee rises and falls from block to block depending on demand at that moment. When many rollups post data at once the price spikes, and when things are quiet it drops. Because rollups must post data continuously, it is hard to know even the cost a few minutes ahead. A future is a trade in which you fix the price now for something you will use later. Blob futures apply this approach to blob space. A rollup that has bought space pays only the price already agreed, even if demand surges when that block arrives. Knowing costs in advance also makes it easier to set stable fees for its users. "Short-term" means it covers only space in nearby blocks, not the distant future. In the Strawmap it sits in the long-term slot of the data layer, grouped with blob streaming and proof of custody. It has not been decided to go into any particular fork. It is still at the research stage, so the content may change or it may be dropped from the roadmap.
How it works
- Buying in advance A rollup buys, at a price set now, blob space that will be included in a near-future block.
- Using it when the time comes When that block arrives, the rollup posts its data into the space it bought. Even if demand surges at that moment and fees rise, it bears only the price it has already paid.