Implement sync committee selection endpoint

common/eth2/src/lib.rs

@@ -141,6 +141,7 @@ pub struct Timeouts {
     pub proposer_duties: Duration,
     pub sync_committee_contribution: Duration,
     pub sync_duties: Duration,
+    pub sync_aggregators: Duration,
     pub get_beacon_blocks_ssz: Duration,
     pub get_debug_beacon_states: Duration,
     pub get_deposit_snapshot: Duration,
@@ -159,6 +160,7 @@ impl Timeouts {
             proposer_duties: timeout,
             sync_committee_contribution: timeout,
             sync_duties: timeout,
+            sync_aggregators: timeout,
             get_beacon_blocks_ssz: timeout,
             get_debug_beacon_states: timeout,
             get_deposit_snapshot: timeout,
@@ -2686,6 +2688,22 @@ impl BeaconNodeHttpClient {
         )
         .await
     }
+
+    /// `POST validator/sync_committee_selections`
+    pub async fn post_validator_sync_committee_selections(
+        &self,
+        selections: &[SyncCommitteeSelection],
+    ) -> Result<GenericResponse<Vec<SyncCommitteeSelection>>, Error> {
+        let mut path = self.eth_path(V1)?;
+
+        path.path_segments_mut()
+            .map_err(|()| Error::InvalidUrl(self.server.clone()))?
+            .push("validator")
+            .push("sync_committee_selections");
+
+        self.post_with_timeout_and_response(path, &selections, self.timeouts.sync_aggregators)
+            .await
+    }
 }
 
 /// Returns `Ok(response)` if the response is a `200 OK` response. Otherwise, creates an

common/eth2/src/types.rs

@@ -955,6 +955,17 @@ pub struct BeaconCommitteeSelection {
     pub slot: Slot,
     pub selection_proof: Signature,
 }
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+
+pub struct SyncCommitteeSelection {
+    #[serde(with = "serde_utils::quoted_u64")]
+    pub validator_index: u64,
+    pub slot: Slot,
+    #[serde(with = "serde_utils::quoted_u64")]
+    pub subcommittee_index: u64,
+    pub selection_proof: Signature,
+}
 // --------- Server Sent Event Types -----------
 
 #[derive(PartialEq, Debug, Serialize, Deserialize, Clone)]