Proposal: Enable Smart Contract Notifications for Direct Data Onboarding

[rvagg]

When FIP-0076 introduced DDO, it included a notification mechanism that allows actors to be informed when data is committed to sectors. However, this capability was initially restricted to only the storage market actor (f05) as a security precaution. This proposal seeks to remove that restriction, enabling any properly designed smart contract to receive these notifications.

The change would unlock significant new possibilities for the Filecoin ecosystem. Smart contracts could directly track when their data is committed to sectors, enabling custom marketplaces to implement their own deal activation logic without relying on the built-in market. Data DAOs could monitor and react to storage commitments in real-time, and new types of data-driven applications could be built that integrate sealed storage with other on-chain primitives.

This change alone does is not sufficient to support self-contained smart contract storage markets based on PoRep, but it is an important step towards this goal.

The DDO design ensures that only storage providers can specify notification receivers, and provides controls over whether notification failures should abort sector commitments. Storage providers would need to carefully manage gas consumption risks, as receiving contracts could potentially consume significant gas during notification processing.

Full FIP draft is available here: #1180

[lanzafame]

@rvagg Out of curiosity, and I am not holding you to any answer, but how far are we from 'This change alone does is not sufficient to support self-contained smart contract storage markets based on PoRep, but it is an important step towards this goal.'?

[rvagg]

The plan is, after posting this, is to work on a SectorStatus method exposed from the miner actor. Discussed here. There's been a bunch more discussion about this, including at the last FDS, I have a lot of notes but need to do a little bit more work on some of the technical questions because it's not trivial.

The picture is something like:

• DDO notifications alone are nice because they are push, but only give you the commit event and nothing else—no terminations, faults, or other lifecycle insight. So you can't build a market around just this, but it helps.
• A SectorStatus would give you a poll style interaction where a market could potentially view the entire lifecycle and react accordingly, but it does need to be invokes in order to do that polling.

If we had a SectorStatus then this FIP wouldn't strictly be necessary for a market that could do the full sector lifecycle, it'd just be a quality of service improvement. You could replace this FIP entirely with a SectorStatus plus a follow-up message from miner software. e.g. once you finish committing a sector, you send another message to a smart contract telling it about your sector, it then goes and looks up the information using SectorStatus and reacts accordingly.

Piece manifests are a nice feature of this FIP though; those are ephemeral now if you don't touch the market actor (and verifreg has some piece information). Having the miner actor deliver it to you is really nice. Without that and just a SectorStatus, you'd want a caller to supply you with the piece manifest so the contract can verify that all the pieces combine to match CommD for the sector.

This FIP is super easy to implement though, the hard bit is writing that all up and adding some additional integration testing in Lotus on our DDO tests.