---
tags: epf,ethereum
---

# EPF Dev Update #14

## Project links

- [Project: EIP-4844 Consensus Client](https://github.com/eth-protocol-fellows/cohort-three/blob/master/projects/4844-consensus-client.md)
- [Design: Builder API for Blobs](https://hackmd.io/@jimmygchen/B1dLR74Io)

## Summary for week 15 (2023/2/6-2023/2/13)

- **Lighthouse backfill sycn rate-limiting** ([lighthouse#3936](https://github.com/sigp/lighthouse/pull/3936)): This week I'm focusing on wrapping up the work on this, mostly addressing review comments and testing. Hopefully this change will land soon! This change will reduce the CPU load for users setting up a new Lighthouse node, by throttling the backfill rate and is configurable if user chooses not to throttle. For background on this, please see [my previous update](https://hackmd.io/ixGLGIbvTsa-VWcxMXcc2A?view#Lighthouse-rate-limit-historical-block-backfill).
- **Builder spec update for Capella** finally merged in ([builder-specs#60](https://github.com/ethereum/builder-specs/pull/60))! :ship:
- **EIP-4844 Builder updates**: there are a couple of open PRs that I need to get back to due to recent changes in spec. I had a catch up with **@realbigsean** earlir this week on the changes related to decoupled blobs & blocks, my plan for the next couple of days:
- Update the diagrams on the [builder update design document](https://hackmd.io/@jimmygchen/B1dLR74Io) to reflect the changes
- Outstanding PRs / work that will be impacted by this change:
- **Add and update types for EIP-4844/Deneb** [builder-specs#61](https://github.com/ethereum/builder-specs/pull/61)
- **Builder updates for Blobs (EIP-4844)** [lighthouse#3808](https://github.com/sigp/lighthouse/pull/3808)
- **Add Deneb (EIP-4844) types and presets** [ralexstokes/ethereum-consensus#170](https://github.com/ralexstokes/ethereum-consensus/pull/170)
- **Add support for EIP-4844 types in [`mev-rs`](https://github.com/ralexstokes/mev-rs)** (WIP)
- **Add `getBlobsSidecar` endpoint** [beacon-APIs#286](https://github.com/ethereum/beacon-APIs/pull/286): spec PR was brought up in the [EIP-4844 implementers call #14](https://github.com/ethereum/pm/issues/718). Most clients have started implementing this, I will follow up on this one and hopefully finalise the spec soon!
- Potentially pick up the work on Blob Signing API in Lighthouse. Issue here: https://github.com/ethereum/beacon-APIs/issues/300

## WIP Tasks

### Backfill sync ([PR](https://github.com/sigp/lighthouse/pull/3936))

- [x] measure batch processing time
- [x] (WIP) address review feedback
- [x] measure batch processing time with CPU limiting (docker)
- [x] increase batch per slot

### EIP-4844

- [ ] update 4844 builder flow
- decoupling ([spec draft](https://github.com/ethereum/consensus-specs/pull/3244))
- blinded blob flow (update [diagram](https://hackmd.io/a8eyJ505Q62gXMbYr0v7_w))
- [ ] update `builder-spec` to support 4844
- [ ] update `ethereum-consensus` & `mev-rs` to support 4844
- [ ] update `lighthouse` 4844 builder flow
- [ ] `beacon-APIs`: download blob ([PR](https://github.com/ethereum/beacon-APIs/pull/286))
- [ ] update lighthouse download blob API

### Other potential tasks

- [ ] Update [`beacon-api-client`](https://github.com/ralexstokes/beacon-api-client) to support 4844
- [ ] Blob Signing API in Lighthouse [issue](https://github.com/ethereum/beacon-APIs/issues/300)

### Meeting recordings

- [x] [EIP-4844 call](https://github.com/ethereum/pm/issues/718)
- [x] [EPF office hour call /w `@Mario Vega` and `@Fredrik`](https://drive.google.com/file/d/122sKL15uZsKkEEmKlLaULTibt-l8mXZS/view?usp=sharing)
- [x] [EPF office hour call with `@ralexstokes` and `@barnabé`]()

### Readings

- [x] [Edelweiss Interop Recap
](https://blog.ethereum.org/2023/02/07/edelweiss-interop-recap)
- [x] [Decoupled blobs](https://hackmd.io/cmYisgxkRuGe9NjX4gr97A?view) by @arnetheduck
- [x] [Blob Pool](https://gist.github.com/karalabe/e1c4e4c2a226926498cc9816d383cecb) by @karalabe