# Dev Update #8
Hi :blush:,
In my [last update](https://hackmd.io/@kevinbogner/HJOn-F7wi), I presented the work done for implementing `sync_committee_rewards` into [Lighthouse](https://github.com/sigp/lighthouse). This week, I had two meetings with [NC](https://github.com/naviechan) to discuss how we want to coordinate the work. The meeting notes can be found [here](https://hackmd.io/@kevinbogner/meeting-notes-dev-rewards-API).

In the following, I want to talk about the current state of our work by explaining our modifications. However, this is just a draft and will most likely be changed in the future after reviews by the Lighthouse team.

## [`sync_committee_rewards.rs`](https://github.com/naviechan/lighthouse/blob/rewards_api/beacon_node/http_api/src/sync_committee_rewards.rs)

This part still needs some modifications. We get different values and then call `compute_sync_aggregate_rewards()`.

pub fn compute_sync_committee_rewards<T: BeaconChainTypes>(
    chain: Arc<BeaconChain<T>>,
    block_id: BlockId,
    validators: Vec<ValidatorId>,
    log: Logger
) -> Result<T, E> {

    let spec: ChainSpec = chain.spec;

    let (block, execution_optimistic) = block_id.blinded_block(&chain)?;

    let slot: Slot = block.message().slot();

    let state_root = chain.state_root_at_slot(slot)?.unwrap();

    let state = chain.get_state(&state_root, Some(slot))?.unwrap();

    let (_, rewards) = compute_sync_aggregate_rewards(&state, &spec)?;

    
    // Create SyncCommitteeRewards with calculated rewards
    Ok(SyncCommitteeAttestationRewards{
        execution_optimistic: false,
        finalized: false,
        data: Vec::new(),
    })

## [`lib.rs`](https://github.com/naviechan/lighthouse/blob/rewards_api/beacon_node/http_api/src/lib.rs#L1711-L1727)

This is our API handler, which supplies a `chain` of type `Arc<BeaconChain>`, which is the handle to everything.

    let post_beacon_rewards_sync_committee = beacon_rewards_path
        .clone()
        .and(warp::path("sync_committee"))
        .and(block_id_or_err)
        .and(warp::path::end())
        .and(warp::body::json())
        .and(log_filter.clone())
        .and_then(
            |chain: Arc<BeaconChain<T>>,
             block_id: BlockId,
             validators: Vec<ValidatorId>,
             log: Logger| {
            // Do something here
            blocking_json_task(move || Ok(sync_committee_rewards::compute_sync_committee_rewards(
                chain, block_id, validators, log)))
        });

## [`sync_committee_attestation_rewards.rs`](https://github.com/naviechan/lighthouse/blob/rewards_api/common/eth2/src/lighthouse/sync_committee_attestation_rewards.rs)

We implement our [schema](https://ethereum.github.io/beacon-APIs/?urls.primaryName=dev#/Experimental/getSyncCommitteeRewards), which we defined in the `beacon-API` endpoint.

#[derive(Debug, PartialEq, Clone, Serialize, Deserialize)]
pub struct SyncCommitteeAttestationRewards {

    pub execution_optimistic: bool,

    pub finalized: bool,

    pub data: Vec<SyncCommitteeAttestationReward>,
    
}

#[derive(Debug, PartialEq, Clone, Serialize, Deserialize)]
pub struct SyncCommitteeAttestationReward {

    pub validator_index: u8,

    pub reward: u64,
    
}

## Conclusion
The endpoint is still in an early stage and will change over time. I'm optimistic that I can give a more precise overview of our work in the next dev update once we finish our draft PR. Until then, some work needs to get done. Bye :wave: