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# System prepended metadata

title: Dev Update Week 8 (robzajac)

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# Dev Update Week 8 (robzajac)

Last week I continued development of the light client APIs in teku. While I was sick for the first few days of the week, towards the end I completed:

- Merged [implementation of merkle multiproofs for SSZ objects in teku](https://github.com/ConsenSys/teku/pull/6538). This gives us the ability to generate an inclusion proof for a field in an SSZ object, which is especially useful for verifying `current_sync_committee` in a `BeaconState` for the light client bootstrap path, and later for light client updates.
- Implemented and opened a PR for the [`GetLightClientBootstrap` endpoint in teku](https://github.com/ConsenSys/teku/pull/6577). This is the first major endpoint of the [light client APIs](https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/full-node.md#deriving-light-client-data), which enables callers to sync to the beacon block header associated with the checkpoint root they provide.
    - Added some integration testing for the endpoint in the teku repo, and validated manually.
    - Received code review from the teku team, to continue iterating on the PR this week.
- Read Vitalik's post on [applications in the Ethereum ecosystem](https://vitalik.ca/general/2022/12/05/excited.html), which has interesting inspiration for Ethereum use cases.

This week I would like to:
- Update the LightClientBootstrap PR and merge into teku, including any additional testing (followup PR with acceptance test and manual testing).
- Work on the interface to `GetLightClientUpdatesByRange`, opening a PR for the SSZ objects and a stubbed endpoint.
- Continue reading and following the latest in light client research and development, specifically etan's latest `consensus-specs` update to [add `ExecutionPayloadHeader` to light client data](https://github.com/ethereum/consensus-specs/pull/3151).