feat: support post-electra attestation and attester slashing events

packages/api/src/beacon/client/events.ts

@@ -13,7 +13,7 @@ export type ApiClient = ApiClientMethods<Endpoints>;
  */
 export function getClient(config: ChainForkConfig, baseUrl: string): ApiClient {
   const definitions = getDefinitions(config);
-  const eventSerdes = getEventSerdes();
+  const eventSerdes = getEventSerdes(config);
 
   return {
     eventstream: async ({topics, signal, onEvent, onError, onClose}) => {

packages/api/src/beacon/routes/events.ts

@@ -13,6 +13,9 @@ import {
   LightClientOptimisticUpdate,
   LightClientFinalityUpdate,
   SSEPayloadAttributes,
+  Attestation,
+  AttesterSlashing,
+  sszTypesFor,
 } from "@lodestar/types";
 import {ForkName} from "@lodestar/params";
 
@@ -104,10 +107,10 @@ export type EventData = {
     block: RootHex;
     executionOptimistic: boolean;
   };
-  [EventType.attestation]: phase0.Attestation;
+  [EventType.attestation]: Attestation;
   [EventType.voluntaryExit]: phase0.SignedVoluntaryExit;
   [EventType.proposerSlashing]: phase0.ProposerSlashing;
-  [EventType.attesterSlashing]: phase0.AttesterSlashing;
+  [EventType.attesterSlashing]: AttesterSlashing;
   [EventType.blsToExecutionChange]: capella.SignedBLSToExecutionChange;
   [EventType.finalizedCheckpoint]: {
     block: RootHex;
@@ -184,7 +187,7 @@ export type TypeJson<T> = {
   fromJson: (data: unknown) => T; // client
 };
 
-export function getTypeByEvent(): {[K in EventType]: TypeJson<EventData[K]>} {
+export function getTypeByEvent(config: ChainForkConfig): {[K in EventType]: TypeJson<EventData[K]>} {
   // eslint-disable-next-line @typescript-eslint/naming-convention
   const WithVersion = <T>(getType: (fork: ForkName) => TypeJson<T>): TypeJson<{data: T; version: ForkName}> => {
     return {
@@ -225,10 +228,28 @@ export function getTypeByEvent(): {[K in EventType]: TypeJson<EventData[K]>} {
       {jsonCase: "eth2"}
     ),
 
-    [EventType.attestation]: ssz.phase0.Attestation,
+    [EventType.attestation]: {
+      toJson: (attestation) => {
+        const fork = config.getForkName(attestation.data.slot);
+        return sszTypesFor(fork).Attestation.toJson(attestation);
+      },
+      fromJson: (attestation) => {
+        const fork = config.getForkName((attestation as Attestation).data.slot);
+        return sszTypesFor(fork).Attestation.fromJson(attestation);
+      },
+    },
     [EventType.voluntaryExit]: ssz.phase0.SignedVoluntaryExit,
     [EventType.proposerSlashing]: ssz.phase0.ProposerSlashing,
-    [EventType.attesterSlashing]: ssz.phase0.AttesterSlashing,
+    [EventType.attesterSlashing]: {
+      toJson: (attesterSlashing) => {
+        const fork = config.getForkName(Number(attesterSlashing.attestation1.data.slot));
+        return sszTypesFor(fork).AttesterSlashing.toJson(attesterSlashing);
+      },
+      fromJson: (attesterSlashing) => {
+        const fork = config.getForkName(Number((attesterSlashing as AttesterSlashing).attestation1.data.slot));
+        return sszTypesFor(fork).AttesterSlashing.fromJson(attesterSlashing);
+      },
+    },
     [EventType.blsToExecutionChange]: ssz.capella.SignedBLSToExecutionChange,
 
     [EventType.finalizedCheckpoint]: new ContainerType(
@@ -269,8 +290,8 @@ export function getTypeByEvent(): {[K in EventType]: TypeJson<EventData[K]>} {
 }
 
 // eslint-disable-next-line @typescript-eslint/explicit-function-return-type
-export function getEventSerdes() {
-  const typeByEvent = getTypeByEvent();
+export function getEventSerdes(config: ChainForkConfig) {
+  const typeByEvent = getTypeByEvent(config);
 
   return {
     toJson: (event: BeaconEvent): unknown => {

packages/api/src/beacon/server/events.ts

@@ -3,7 +3,7 @@ import {ApiError, ApplicationMethods, FastifyRoutes, createFastifyRoutes} from "
 import {Endpoints, getDefinitions, eventTypes, getEventSerdes} from "../routes/events.js";
 
 export function getRoutes(config: ChainForkConfig, methods: ApplicationMethods<Endpoints>): FastifyRoutes<Endpoints> {
-  const eventSerdes = getEventSerdes();
+  const eventSerdes = getEventSerdes(config);
   const serverRoutes = createFastifyRoutes(getDefinitions(config), methods);
 
   return {

packages/api/test/unit/beacon/oapiSpec.test.ts

@@ -108,7 +108,7 @@ describe("eventstream event data", () => {
     }
   });
 
-  const eventSerdes = routes.events.getEventSerdes();
+  const eventSerdes = routes.events.getEventSerdes(config);
   const knownTopics = new Set<string>(Object.values(routes.events.eventTypes));
 
   for (const [topic, {value}] of Object.entries(eventstreamExamples ?? {}).filter(