feat(static-sharding)!: allow multiple pubSubTopics (#1586)

* `ProtocolCreateOptions` now has `pubSubTopic` as `pubSubTopic[]`

* chore: update encoder & decoder to support `PubSubTopic`

* feat(protocols): allow multiple `PubSubTopic[]`

* feat(relay): allow multiple `PubSubTopic[]`

* chore(tests): update for new API

* chore: minor fixes

* chore: make store more robust

* fix(relay): correctly set types

* chore(address comments): update terminology around configured pubsub topics

* chore(address comments): minor refactoring

* chore(relay): split `subscribe` into smaller functions for readability & modularity

* chore(address comments): refactor `waitForGossipSubPeerInMesh`

* chore(store): only allow to query one `pubSubTopic`

* fix: `store` bug

* feat(tests): add some basic tests

* sharding utils

* address comments

* feat(relay): re-add API for `getMeshPeers`

* update error message

Co-authored-by: fryorcraken <110212804+fryorcraken@users.noreply.github.com>

* refactor for new API

* feat: simplify handling of observers (#1614)

* refactor: simplify handling of observers

* refactor: Remove redundant PubSubTopic from Observer

* use `??` instead of `||`

* update `pubsubTopic` to `pubSubTopic`

* update `interval` typo

* change occurence of `pubsubTopic` to `pubSubTopic`

* relay: rm `getAllMeshPeers` and make `pubSubTopics` public

* relay: use `push_or_init_map` and move to `utils`

* fix: update API for tests

* fix: relay waitForRemotePeer

---------

Co-authored-by: fryorcraken <110212804+fryorcraken@users.noreply.github.com>

.cspell.json

@@ -39,6 +39,7 @@
     "exponentiate",
     "extip",
     "fanout",
+    "sharded",
     "floodsub",
     "fontsource",
     "globby",

package-lock.json

@@ -6506,7 +6506,8 @@
     },
     "node_modules/chai": {
       "version": "4.3.8",
-      "license": "MIT",
+      "resolved": "https://registry.npmjs.org/chai/-/chai-4.3.8.tgz",
+      "integrity": "sha512-vX4YvVVtxlfSZ2VecZgFUTU5qPCYsobVI2O9FmwEXBhDigYGQA6jRXCycIs1yJnnWbZ6/+a2zNIF5DfVCcJBFQ==",
       "dependencies": {
         "assertion-error": "^1.1.0",
         "check-error": "^1.0.2",
@@ -26180,7 +26181,7 @@
       "version": "0.0.11",
       "license": "MIT OR Apache-2.0",
       "dependencies": {
-        "@waku/interfaces": "0.0.18",
+        "chai": "^4.3.8",
         "debug": "^4.3.4",
         "uint8arrays": "^4.0.4"
       },
@@ -26189,7 +26190,7 @@
         "@rollup/plugin-json": "^6.0.0",
         "@rollup/plugin-node-resolve": "^15.1.0",
         "@waku/build-utils": "*",
-        "@waku/interfaces": "0.0.17",
+        "@waku/interfaces": "0.0.18",
         "cspell": "^7.3.2",
         "npm-run-all": "^4.1.5",
         "rollup": "^3.29.2"
@@ -26197,14 +26198,6 @@
       "engines": {
         "node": ">=18"
       }
-    },
-    "packages/utils/node_modules/@waku/interfaces": {
-      "version": "0.0.17",
-      "dev": true,
-      "license": "MIT OR Apache-2.0",
-      "engines": {
-        "node": ">=16"
-      }
     }
   },
   "dependencies": {
@@ -29401,18 +29394,13 @@
         "@rollup/plugin-json": "^6.0.0",
         "@rollup/plugin-node-resolve": "^15.1.0",
         "@waku/build-utils": "*",
-        "@waku/interfaces": "0.0.17",
+        "@waku/interfaces": "0.0.18",
+        "chai": "^4.3.8",
         "cspell": "^7.3.2",
         "debug": "^4.3.4",
         "npm-run-all": "^4.1.5",
         "rollup": "^3.29.2",
         "uint8arrays": "^4.0.4"
-      },
-      "dependencies": {
-        "@waku/interfaces": {
-          "version": "0.0.17",
-          "dev": true
-        }
       }
     },
     "@webassemblyjs/ast": {
@@ -30521,6 +30509,8 @@
     },
     "chai": {
       "version": "4.3.8",
+      "resolved": "https://registry.npmjs.org/chai/-/chai-4.3.8.tgz",
+      "integrity": "sha512-vX4YvVVtxlfSZ2VecZgFUTU5qPCYsobVI2O9FmwEXBhDigYGQA6jRXCycIs1yJnnWbZ6/+a2zNIF5DfVCcJBFQ==",
       "requires": {
         "assertion-error": "^1.1.0",
         "check-error": "^1.0.2",

packages/core/src/lib/filter/index.ts

@@ -17,7 +17,11 @@ import type {
   Unsubscribe
 } from "@waku/interfaces";
 import { WakuMessage } from "@waku/proto";
-import { groupByContentTopic, toAsyncIterator } from "@waku/utils";
+import {
+  ensurePubsubTopicIsConfigured,
+  groupByContentTopic,
+  toAsyncIterator
+} from "@waku/utils";
 import debug from "debug";
 import all from "it-all";
 import * as lp from "it-length-prefixed";
@@ -230,7 +234,7 @@ class Subscription {
 }
 
 class Filter extends BaseProtocol implements IReceiver {
-  private readonly options: ProtocolCreateOptions;
+  private readonly pubSubTopics: PubSubTopic[] = [];
   private activeSubscriptions = new Map<string, Subscription>();
   private readonly NUM_PEERS_PROTOCOL = 1;
 
@@ -253,19 +257,22 @@ class Filter extends BaseProtocol implements IReceiver {
   constructor(libp2p: Libp2p, options?: ProtocolCreateOptions) {
     super(FilterCodecs.SUBSCRIBE, libp2p.components);
 
+    this.pubSubTopics = options?.pubSubTopics || [DefaultPubSubTopic];
+
     libp2p.handle(FilterCodecs.PUSH, this.onRequest.bind(this)).catch((e) => {
       log("Failed to register ", FilterCodecs.PUSH, e);
     });
 
     this.activeSubscriptions = new Map();
-
-    this.options = options ?? {};
   }
 
-  async createSubscription(pubSubTopic?: string): Promise<Subscription> {
+  async createSubscription(
-    const _pubSubTopic =
+    pubSubTopic: string = DefaultPubSubTopic
-      pubSubTopic ?? this.options.pubSubTopic ?? DefaultPubSubTopic;
+  ): Promise<Subscription> {
+    ensurePubsubTopicIsConfigured(pubSubTopic, this.pubSubTopics);
 
+    //TODO: get a relevant peer for the topic/shard
+    // https://github.com/waku-org/js-waku/pull/1586#discussion_r1336428230
     const peer = (
       await this.getPeers({
         maxBootstrapPeers: 1,
@@ -274,11 +281,11 @@ class Filter extends BaseProtocol implements IReceiver {
     )[0];
 
     const subscription =
-      this.getActiveSubscription(_pubSubTopic, peer.id.toString()) ??
+      this.getActiveSubscription(pubSubTopic, peer.id.toString()) ??
       this.setActiveSubscription(
-        _pubSubTopic,
+        pubSubTopic,
         peer.id.toString(),
-        new Subscription(_pubSubTopic, peer, this.getStream.bind(this, peer))
+        new Subscription(pubSubTopic, peer, this.getStream.bind(this, peer))
       );
 
     return subscription;

packages/core/src/lib/keep_alive_manager.ts

@@ -1,6 +1,6 @@
 import type { PeerId } from "@libp2p/interface/peer-id";
 import type { PeerStore } from "@libp2p/interface/peer-store";
-import type { IRelay } from "@waku/interfaces";
+import type { IRelay, PeerIdStr } from "@waku/interfaces";
 import type { KeepAliveOptions } from "@waku/interfaces";
 import { utf8ToBytes } from "@waku/utils/bytes";
 import debug from "debug";
@@ -13,7 +13,7 @@ const log = debug("waku:keep-alive");
 
 export class KeepAliveManager {
   private pingKeepAliveTimers: Map<string, ReturnType<typeof setInterval>>;
-  private relayKeepAliveTimers: Map<PeerId, ReturnType<typeof setInterval>>;
+  private relayKeepAliveTimers: Map<PeerId, ReturnType<typeof setInterval>[]>;
   private options: KeepAliveOptions;
   private relay?: IRelay;
 
@@ -66,17 +66,12 @@ export class KeepAliveManager {
 
     const relay = this.relay;
     if (relay && relayPeriodSecs !== 0) {
-      const encoder = createEncoder({
+      const intervals = this.scheduleRelayPings(
-        contentTopic: RelayPingContentTopic,
+        relay,
-        ephemeral: true
+        relayPeriodSecs,
-      });
+        peerId.toString()
-      const interval = setInterval(() => {
+      );
-        log("Sending Waku Relay ping message");
+      this.relayKeepAliveTimers.set(peerId, intervals);
-        relay
-          .send(encoder, { payload: new Uint8Array([1]) })
-          .catch((e) => log("Failed to send relay ping", e));
-      }, relayPeriodSecs * 1000);
-      this.relayKeepAliveTimers.set(peerId, interval);
     }
   }
 
@@ -89,7 +84,7 @@ export class KeepAliveManager {
     }
 
     if (this.relayKeepAliveTimers.has(peerId)) {
-      clearInterval(this.relayKeepAliveTimers.get(peerId));
+      this.relayKeepAliveTimers.get(peerId)?.map(clearInterval);
       this.relayKeepAliveTimers.delete(peerId);
     }
   }
@@ -105,4 +100,32 @@ export class KeepAliveManager {
     this.pingKeepAliveTimers.clear();
     this.relayKeepAliveTimers.clear();
   }
+
+  private scheduleRelayPings(
+    relay: IRelay,
+    relayPeriodSecs: number,
+    peerIdStr: PeerIdStr
+  ): NodeJS.Timeout[] {
+    // send a ping message to each PubSubTopic the peer is part of
+    const intervals: NodeJS.Timeout[] = [];
+    for (const topic of relay.pubSubTopics) {
+      const meshPeers = relay.getMeshPeers(topic);
+      if (!meshPeers.includes(peerIdStr)) continue;
+
+      const encoder = createEncoder({
+        pubSubTopic: topic,
+        contentTopic: RelayPingContentTopic,
+        ephemeral: true
+      });
+      const interval = setInterval(() => {
+        log("Sending Waku Relay ping message");
+        relay
+          .send(encoder, { payload: new Uint8Array([1]) })
+          .catch((e) => log("Failed to send relay ping", e));
+      }, relayPeriodSecs * 1000);
+      intervals.push(interval);
+    }
+
+    return intervals;
+  }
 }

packages/core/src/lib/light_push/index.ts

@@ -6,11 +6,12 @@ import {
   IMessage,
   Libp2p,
   ProtocolCreateOptions,
+  PubSubTopic,
   SendError,
   SendResult
 } from "@waku/interfaces";
 import { PushResponse } from "@waku/proto";
-import { isSizeValid } from "@waku/utils";
+import { ensurePubsubTopicIsConfigured, isSizeValid } from "@waku/utils";
 import debug from "debug";
 import all from "it-all";
 import * as lp from "it-length-prefixed";
@@ -41,12 +42,12 @@ type PreparePushMessageResult =
  * Implements the [Waku v2 Light Push protocol](https://rfc.vac.dev/spec/19/).
  */
 class LightPush extends BaseProtocol implements ILightPush {
-  options: ProtocolCreateOptions;
+  private readonly pubSubTopics: PubSubTopic[];
   private readonly NUM_PEERS_PROTOCOL = 1;
 
   constructor(libp2p: Libp2p, options?: ProtocolCreateOptions) {
     super(LightPushCodec, libp2p.components);
-    this.options = options || {};
+    this.pubSubTopics = options?.pubSubTopics ?? [DefaultPubSubTopic];
   }
 
   private async preparePushMessage(
@@ -82,7 +83,9 @@ class LightPush extends BaseProtocol implements ILightPush {
   }
 
   async send(encoder: IEncoder, message: IMessage): Promise<SendResult> {
-    const { pubSubTopic = DefaultPubSubTopic } = this.options;
+    const { pubSubTopic } = encoder;
+    ensurePubsubTopicIsConfigured(pubSubTopic, this.pubSubTopics);
+
     const recipients: PeerId[] = [];
 
     const { query, error: preparationError } = await this.preparePushMessage(
@@ -98,6 +101,7 @@ class LightPush extends BaseProtocol implements ILightPush {
       };
     }
 
+    //TODO: get a relevant peer for the topic/shard
     const peers = await this.getPeers({
       maxBootstrapPeers: 1,
       numPeers: this.NUM_PEERS_PROTOCOL

packages/core/src/lib/message/version_0.ts

@@ -6,11 +6,14 @@ import type {
   IMessage,
   IMetaSetter,
   IProtoMessage,
-  IRateLimitProof
+  IRateLimitProof,
+  PubSubTopic
 } from "@waku/interfaces";
 import { proto_message as proto } from "@waku/proto";
 import debug from "debug";
 
+import { DefaultPubSubTopic } from "../constants.js";
+
 const log = debug("waku:message:version-0");
 const OneMillion = BigInt(1_000_000);
 
@@ -73,6 +76,7 @@ export class Encoder implements IEncoder {
   constructor(
     public contentTopic: string,
     public ephemeral: boolean = false,
+    public pubSubTopic: PubSubTopic,
     public metaSetter?: IMetaSetter
   ) {
     if (!contentTopic || contentTopic === "") {
@@ -115,15 +119,19 @@ export class Encoder implements IEncoder {
  * messages.
  */
 export function createEncoder({
+  pubSubTopic = DefaultPubSubTopic,
   contentTopic,
   ephemeral,
   metaSetter
 }: EncoderOptions): Encoder {
-  return new Encoder(contentTopic, ephemeral, metaSetter);
+  return new Encoder(contentTopic, ephemeral, pubSubTopic, metaSetter);
 }
 
 export class Decoder implements IDecoder<DecodedMessage> {
-  constructor(public contentTopic: string) {
+  constructor(
+    public pubSubTopic: PubSubTopic,
+    public contentTopic: string
+  ) {
     if (!contentTopic || contentTopic === "") {
       throw new Error("Content topic must be specified");
     }
@@ -173,6 +181,9 @@ export class Decoder implements IDecoder<DecodedMessage> {
  *
  * @param contentTopic The resulting decoder will only decode messages with this content topic.
  */
-export function createDecoder(contentTopic: string): Decoder {
+export function createDecoder(
-  return new Decoder(contentTopic);
+  contentTopic: string,
+  pubsubTopic: PubSubTopic = DefaultPubSubTopic
+): Decoder {
+  return new Decoder(pubsubTopic, contentTopic);
 }

packages/core/src/lib/store/index.ts

@@ -6,10 +6,11 @@ import {
   IDecoder,
   IStore,
   Libp2p,
-  ProtocolCreateOptions
+  ProtocolCreateOptions,
+  PubSubTopic
 } from "@waku/interfaces";
 import { proto_store as proto } from "@waku/proto";
-import { isDefined } from "@waku/utils";
+import { ensurePubsubTopicIsConfigured, isDefined } from "@waku/utils";
 import { concat, utf8ToBytes } from "@waku/utils/bytes";
 import debug from "debug";
 import all from "it-all";
@@ -74,12 +75,12 @@ export interface QueryOptions {
  * The Waku Store protocol can be used to retrieved historical messages.
  */
 class Store extends BaseProtocol implements IStore {
-  options: ProtocolCreateOptions;
+  private readonly pubSubTopics: PubSubTopic[];
   private readonly NUM_PEERS_PROTOCOL = 1;
 
   constructor(libp2p: Libp2p, options?: ProtocolCreateOptions) {
     super(StoreCodec, libp2p.components);
-    this.options = options ?? {};
+    this.pubSubTopics = options?.pubSubTopics ?? [DefaultPubSubTopic];
   }
 
   /**
@@ -206,12 +207,20 @@ class Store extends BaseProtocol implements IStore {
    * @throws If not able to reach a Waku Store peer to query,
    * or if an error is encountered when processing the reply,
    * or if two decoders with the same content topic are passed.
+   *
+   * This API only supports querying a single pubsub topic at a time.
+   * If multiple decoders are provided, they must all have the same pubsub topic.
+   * @throws If multiple decoders with different pubsub topics are provided.
+   * @throws If no decoders are provided.
+   * @throws If no decoders are found for the provided pubsub topic.
    */
   async *queryGenerator<T extends IDecodedMessage>(
     decoders: IDecoder<T>[],
     options?: QueryOptions
   ): AsyncGenerator<Promise<T | undefined>[]> {
-    const { pubSubTopic = DefaultPubSubTopic } = this.options;
+    if (decoders.length === 0) {
+      throw new Error("No decoders provided");
+    }
 
     let startTime, endTime;
 
@@ -220,6 +229,23 @@ class Store extends BaseProtocol implements IStore {
       endTime = options.timeFilter.endTime;
     }
 
+    // convert array to set to remove duplicates
+    const uniquePubSubTopicsInQuery = Array.from(
+      new Set(decoders.map((decoder) => decoder.pubSubTopic))
+    );
+
+    // If multiple pubsub topics are provided, throw an error
+    if (uniquePubSubTopicsInQuery.length > 1) {
+      throw new Error(
+        "API does not support querying multiple pubsub topics at once"
+      );
+    }
+
+    // we can be certain that there is only one pubsub topic in the query
+    const pubSubTopicForQuery = uniquePubSubTopicsInQuery[0];
+
+    ensurePubsubTopicIsConfigured(pubSubTopicForQuery, this.pubSubTopics);
+
     const decodersAsMap = new Map();
     decoders.forEach((dec) => {
       if (decodersAsMap.has(dec.contentTopic)) {
@@ -230,11 +256,17 @@ class Store extends BaseProtocol implements IStore {
       decodersAsMap.set(dec.contentTopic, dec);
     });
 
-    const contentTopics = decoders.map((dec) => dec.contentTopic);
+    const contentTopics = decoders
+      .filter((decoder) => decoder.pubSubTopic === pubSubTopicForQuery)
+      .map((dec) => dec.contentTopic);
+
+    if (contentTopics.length === 0) {
+      throw new Error("No decoders found for topic " + pubSubTopicForQuery);
+    }
 
     const queryOpts = Object.assign(
       {
-        pubSubTopic: pubSubTopic,
+        pubSubTopic: pubSubTopicForQuery,
         pageDirection: PageDirection.BACKWARD,
         pageSize: DefaultPageSize
       },

packages/core/src/lib/wait_for_remote_peer.ts

@@ -96,15 +96,18 @@ async function waitForConnectedPeer(protocol: IBaseProtocol): Promise<void> {
 }
 
 /**
- * Wait for a peer with the given protocol to be connected and in the gossipsub
+ * Wait for at least one peer with the given protocol to be connected and in the gossipsub
- * mesh.
+ * mesh for all pubSubTopics.
  */
 async function waitForGossipSubPeerInMesh(waku: IRelay): Promise<void> {
   let peers = waku.getMeshPeers();
+  const pubSubTopics = waku.pubSubTopics;
 
-  while (peers.length == 0) {
+  for (const topic of pubSubTopics) {
-    await pEvent(waku.gossipSub, "gossipsub:heartbeat");
+    while (peers.length == 0) {
-    peers = waku.getMeshPeers();
+      await pEvent(waku.gossipSub, "gossipsub:heartbeat");
+      peers = waku.getMeshPeers(topic);
+    }
   }
 }
 

packages/interfaces/src/message.ts

@@ -1,3 +1,5 @@
+import type { PubSubTopic } from "./misc.js";
+
 export interface IRateLimitProof {
   proof: Uint8Array;
   merkleRoot: Uint8Array;
@@ -36,6 +38,7 @@ export interface IMetaSetter {
 }
 
 export interface EncoderOptions {
+  pubSubTopic?: PubSubTopic;
   /** The content topic to set on outgoing messages. */
   contentTopic: string;
   /**
@@ -52,6 +55,7 @@ export interface EncoderOptions {
 }
 
 export interface IEncoder {
+  pubSubTopic: PubSubTopic;
   contentTopic: string;
   ephemeral: boolean;
   toWire: (message: IMessage) => Promise<Uint8Array | undefined>;
@@ -61,7 +65,7 @@ export interface IEncoder {
 export interface IDecodedMessage {
   payload: Uint8Array;
   contentTopic: string;
-  pubSubTopic: string;
+  pubSubTopic: PubSubTopic;
   timestamp: Date | undefined;
   rateLimitProof: IRateLimitProof | undefined;
   ephemeral: boolean | undefined;
@@ -69,6 +73,7 @@ export interface IDecodedMessage {
 }
 
 export interface IDecoder<T extends IDecodedMessage> {
+  pubSubTopic: PubSubTopic;
   contentTopic: string;
   fromWireToProtoObj: (bytes: Uint8Array) => Promise<IProtoMessage | undefined>;
   fromProtoObj: (

packages/interfaces/src/protocols.ts

@@ -4,6 +4,7 @@ import type { Peer, PeerStore } from "@libp2p/interface/peer-store";
 import type { Libp2pOptions } from "libp2p";
 
 import type { IDecodedMessage } from "./message.js";
+import type { PubSubTopic } from "./misc.js";
 
 export enum Protocols {
   Relay = "relay",
@@ -22,18 +23,23 @@ export interface IBaseProtocol {
 
 export type ProtocolCreateOptions = {
   /**
+   * Waku supports usage of multiple pubsub topics, but this is still in early stages.
+   * Waku implements sharding to achieve scalability
+   * The format of the sharded topic is `/waku/2/rs/<shard_cluster_index>/<shard_number>`
+   * To learn more about the sharding specifications implemented, see [Relay Sharding](https://rfc.vac.dev/spec/51/).
    * The PubSub Topic to use. Defaults to {@link @waku/core!DefaultPubSubTopic }.
    *
-   * One and only one pubsub topic is used by Waku. This is used by:
+   * If no pubsub topic is specified, the default pubsub topic is used.
+   * The set of pubsub topics that are used to initialize the Waku node, will need to be used by the protocols as well
+   * You cannot currently add or remove pubsub topics after initialization.
+   * This is used by:
    * - WakuRelay to receive, route and send messages,
    * - WakuLightPush to send messages,
    * - WakuStore to retrieve messages.
-   *
-   * The usage of the default pubsub topic is recommended.
    * See [Waku v2 Topic Usage Recommendations](https://rfc.vac.dev/spec/23/) for details.
    *
    */
-  pubSubTopic?: string;
+  pubSubTopics?: PubSubTopic[];
   /**
    * You can pass options to the `Libp2p` instance used by {@link @waku/core!WakuNode} using the `libp2p` property.
    * This property is the same type as the one passed to [`Libp2p.create`](https://github.com/libp2p/js-libp2p/blob/master/doc/API.md#create)
@@ -71,6 +77,11 @@ export enum SendError {
    * Compressing the message or using an alternative strategy for large messages is recommended.
    */
   SIZE_TOO_BIG = "Size is too big",
+  /**
+   * The PubSubTopic passed to the send function is not configured on the Waku node.
+   * Please ensure that the PubSubTopic is used when initializing the Waku node.
+   */
+  TOPIC_NOT_CONFIGURED = "Topic not configured",
   /**
    * Failure to find a peer with suitable protocols. This may due to a connection issue.
    * Mitigation can be: retrying after a given time period, display connectivity issue

packages/interfaces/src/relay.ts

@@ -1,6 +1,7 @@
 import type { GossipSub } from "@chainsafe/libp2p-gossipsub";
 import type { PeerIdStr, TopicStr } from "@chainsafe/libp2p-gossipsub/types";
 
+import { PubSubTopic } from "./misc.js";
 import { IReceiver } from "./receiver.js";
 import type { ISender } from "./sender.js";
 
@@ -12,6 +13,7 @@ import type { ISender } from "./sender.js";
  * @property getMeshPeers - Function to retrieve the mesh peers for a given topic or all topics if none is specified. Returns an array of peer IDs as strings.
  */
 export interface IRelayAPI {
+  readonly pubSubTopics: Set<PubSubTopic>;
   readonly gossipSub: GossipSub;
   start: () => Promise<void>;
   getMeshPeers: (topic?: TopicStr) => PeerIdStr[];

packages/message-encryption/src/ecies.ts

@@ -1,5 +1,6 @@
+import { DefaultPubSubTopic } from "@waku/core";
 import { Decoder as DecoderV0 } from "@waku/core/lib/message/version_0";
-import { IMetaSetter } from "@waku/interfaces";
+import { IMetaSetter, PubSubTopic } from "@waku/interfaces";
 import type {
   EncoderOptions as BaseEncoderOptions,
   IDecoder,
@@ -32,6 +33,7 @@ const log = debug("waku:message-encryption:ecies");
 
 class Encoder implements IEncoder {
   constructor(
+    public pubSubTopic: PubSubTopic,
     public contentTopic: string,
     private publicKey: Uint8Array,
     private sigPrivKey?: Uint8Array,
@@ -95,6 +97,7 @@ export interface EncoderOptions extends BaseEncoderOptions {
  * in [26/WAKU2-PAYLOAD](https://rfc.vac.dev/spec/26/).
  */
 export function createEncoder({
+  pubSubTopic = DefaultPubSubTopic,
   contentTopic,
   publicKey,
   sigPrivKey,
@@ -102,6 +105,7 @@ export function createEncoder({
   metaSetter
 }: EncoderOptions): Encoder {
   return new Encoder(
+    pubSubTopic,
     contentTopic,
     publicKey,
     sigPrivKey,
@@ -112,10 +116,11 @@ export function createEncoder({
 
 class Decoder extends DecoderV0 implements IDecoder<DecodedMessage> {
   constructor(
+    pubSubTopic: PubSubTopic,
     contentTopic: string,
     private privateKey: Uint8Array
   ) {
-    super(contentTopic);
+    super(pubSubTopic, contentTopic);
   }
 
   async fromProtoObj(
@@ -183,7 +188,8 @@ class Decoder extends DecoderV0 implements IDecoder<DecodedMessage> {
  */
 export function createDecoder(
   contentTopic: string,
-  privateKey: Uint8Array
+  privateKey: Uint8Array,
+  pubSubTopic: PubSubTopic = DefaultPubSubTopic
 ): Decoder {
-  return new Decoder(contentTopic, privateKey);
+  return new Decoder(pubSubTopic, contentTopic, privateKey);
 }

packages/message-encryption/src/symmetric.ts

@@ -1,3 +1,4 @@
+import { DefaultPubSubTopic } from "@waku/core";
 import { Decoder as DecoderV0 } from "@waku/core/lib/message/version_0";
 import type {
   EncoderOptions as BaseEncoderOptions,
@@ -5,7 +6,8 @@ import type {
   IEncoder,
   IMessage,
   IMetaSetter,
-  IProtoMessage
+  IProtoMessage,
+  PubSubTopic
 } from "@waku/interfaces";
 import { WakuMessage } from "@waku/proto";
 import debug from "debug";
@@ -27,6 +29,7 @@ const log = debug("waku:message-encryption:symmetric");
 
 class Encoder implements IEncoder {
   constructor(
+    public pubSubTopic: PubSubTopic,
     public contentTopic: string,
     private symKey: Uint8Array,
     private sigPrivKey?: Uint8Array,
@@ -90,21 +93,30 @@ export interface EncoderOptions extends BaseEncoderOptions {
  * in [26/WAKU2-PAYLOAD](https://rfc.vac.dev/spec/26/).
  */
 export function createEncoder({
+  pubSubTopic = DefaultPubSubTopic,
   contentTopic,
   symKey,
   sigPrivKey,
   ephemeral = false,
   metaSetter
 }: EncoderOptions): Encoder {
-  return new Encoder(contentTopic, symKey, sigPrivKey, ephemeral, metaSetter);
+  return new Encoder(
+    pubSubTopic,
+    contentTopic,
+    symKey,
+    sigPrivKey,
+    ephemeral,
+    metaSetter
+  );
 }
 
 class Decoder extends DecoderV0 implements IDecoder<DecodedMessage> {
   constructor(
+    pubSubTopic: PubSubTopic,
     contentTopic: string,
     private symKey: Uint8Array
   ) {
-    super(contentTopic);
+    super(pubSubTopic, contentTopic);
   }
 
   async fromProtoObj(
@@ -172,7 +184,8 @@ class Decoder extends DecoderV0 implements IDecoder<DecodedMessage> {
  */
 export function createDecoder(
   contentTopic: string,
-  symKey: Uint8Array
+  symKey: Uint8Array,
+  pubSubTopic: PubSubTopic = DefaultPubSubTopic
 ): Decoder {
-  return new Decoder(contentTopic, symKey);
+  return new Decoder(pubSubTopic, contentTopic, symKey);
 }

packages/relay/src/index.ts

@@ -21,10 +21,12 @@ import {
   IRelay,
   Libp2p,
   ProtocolCreateOptions,
+  PubSubTopic,
   SendError,
   SendResult
 } from "@waku/interfaces";
-import { groupByContentTopic, isSizeValid, toAsyncIterator } from "@waku/utils";
+import { isSizeValid, toAsyncIterator } from "@waku/utils";
+import { pushOrInitMapSet } from "@waku/utils";
 import debug from "debug";
 
 import { RelayCodecs } from "./constants.js";
@@ -46,7 +48,7 @@ export type ContentTopic = string;
  * Throws if libp2p.pubsub does not support Waku Relay
  */
 class Relay implements IRelay {
-  private readonly pubSubTopic: string;
+  public readonly pubSubTopics: Set<PubSubTopic>;
   private defaultDecoder: IDecoder<IDecodedMessage>;
 
   public static multicodec: string = RelayCodecs[0];
@@ -56,7 +58,7 @@ class Relay implements IRelay {
    * observers called when receiving new message.
    * Observers under key `""` are always called.
    */
-  private observers: Map<ContentTopic, Set<unknown>>;
+  private observers: Map<PubSubTopic, Map<ContentTopic, Set<unknown>>>;
 
   constructor(libp2p: Libp2p, options?: Partial<RelayCreateOptions>) {
     if (!this.isRelayPubSub(libp2p.services.pubsub)) {
@@ -66,21 +68,22 @@ class Relay implements IRelay {
     }
 
     this.gossipSub = libp2p.services.pubsub as GossipSub;
-    this.pubSubTopic = options?.pubSubTopic ?? DefaultPubSubTopic;
+    this.pubSubTopics = new Set(options?.pubSubTopics ?? [DefaultPubSubTopic]);
 
     if (this.gossipSub.isStarted()) {
-      this.gossipSubSubscribe(this.pubSubTopic);
+      this.subscribeToAllTopics();
     }
 
     this.observers = new Map();
 
+    // Default PubSubTopic decoder
     // TODO: User might want to decide what decoder should be used (e.g. for RLN)
     this.defaultDecoder = new TopicOnlyDecoder();
   }
 
   /**
    * Mounts the gossipsub protocol onto the libp2p node
-   * and subscribes to the default topic.
+   * and subscribes to all the topics.
    *
    * @override
    * @returns {void}
@@ -91,7 +94,7 @@ class Relay implements IRelay {
     }
 
     await this.gossipSub.start();
-    this.gossipSubSubscribe(this.pubSubTopic);
+    this.subscribeToAllTopics();
   }
 
   /**
@@ -99,6 +102,16 @@ class Relay implements IRelay {
    */
   public async send(encoder: IEncoder, message: IMessage): Promise<SendResult> {
     const recipients: PeerId[] = [];
+
+    const { pubSubTopic } = encoder;
+    if (!this.pubSubTopics.has(pubSubTopic)) {
+      log("Failed to send waku relay: topic not configured");
+      return {
+        recipients,
+        errors: [SendError.TOPIC_NOT_CONFIGURED]
+      };
+    }
+
     if (!isSizeValid(message.payload)) {
       log("Failed to send waku relay: message is bigger that 1MB");
       return {
@@ -116,50 +129,49 @@ class Relay implements IRelay {
       };
     }
 
-    return this.gossipSub.publish(this.pubSubTopic, msg);
+    return this.gossipSub.publish(pubSubTopic, msg);
   }
 
-  /**
-   * Add an observer and associated Decoder to process incoming messages on a given content topic.
-   *
-   * @returns Function to delete the observer
-   */
   public subscribe<T extends IDecodedMessage>(
     decoders: IDecoder<T> | IDecoder<T>[],
     callback: Callback<T>
   ): () => void {
-    const contentTopicToObservers = Array.isArray(decoders)
+    const observers: Array<[PubSubTopic, Observer<T>]> = [];
-      ? toObservers(decoders, callback)
-      : toObservers([decoders], callback);
 
-    for (const contentTopic of contentTopicToObservers.keys()) {
+    for (const decoder of Array.isArray(decoders) ? decoders : [decoders]) {
-      const currObservers = this.observers.get(contentTopic) || new Set();
+      const { pubSubTopic } = decoder;
-      const newObservers =
+      const ctObs: Map<ContentTopic, Set<Observer<T>>> = this.observers.get(
-        contentTopicToObservers.get(contentTopic) || new Set();
+        pubSubTopic
+      ) ?? new Map();
+      const observer = { pubSubTopic, decoder, callback };
+      pushOrInitMapSet(ctObs, decoder.contentTopic, observer);
 
-      this.observers.set(contentTopic, union(currObservers, newObservers));
+      this.observers.set(pubSubTopic, ctObs);
+      observers.push([pubSubTopic, observer]);
     }
 
     return () => {
-      for (const contentTopic of contentTopicToObservers.keys()) {
+      this.removeObservers(observers);
-        const currentObservers = this.observers.get(contentTopic) || new Set();
-        const observersToRemove =
-          contentTopicToObservers.get(contentTopic) || new Set();
-
-        const nextObservers = leftMinusJoin(
-          currentObservers,
-          observersToRemove
-        );
-
-        if (nextObservers.size) {
-          this.observers.set(contentTopic, nextObservers);
-        } else {
-          this.observers.delete(contentTopic);
-        }
-      }
     };
   }
 
+  private removeObservers<T extends IDecodedMessage>(
+    observers: Array<[PubSubTopic, Observer<T>]>
+  ): void {
+    for (const [pubSubTopic, observer] of observers) {
+      const ctObs = this.observers.get(pubSubTopic);
+      if (!ctObs) continue;
+
+      const contentTopic = observer.decoder.contentTopic;
+      const _obs = ctObs.get(contentTopic);
+      if (!_obs) continue;
+
+      _obs.delete(observer);
+      ctObs.set(contentTopic, _obs);
+      this.observers.set(pubSubTopic, ctObs);
+    }
+  }
+
   public toSubscriptionIterator<T extends IDecodedMessage>(
     decoders: IDecoder<T> | IDecoder<T>[]
   ): Promise<IAsyncIterator<T>> {
@@ -168,12 +180,20 @@ class Relay implements IRelay {
 
   public getActiveSubscriptions(): ActiveSubscriptions {
     const map = new Map();
-    map.set(this.pubSubTopic, this.observers.keys());
+    for (const pubSubTopic of this.pubSubTopics) {
+      map.set(pubSubTopic, Array.from(this.observers.keys()));
+    }
     return map;
   }
 
-  public getMeshPeers(topic?: TopicStr): PeerIdStr[] {
+  public getMeshPeers(topic: TopicStr = DefaultPubSubTopic): PeerIdStr[] {
-    return this.gossipSub.getMeshPeers(topic ?? this.pubSubTopic);
+    return this.gossipSub.getMeshPeers(topic);
+  }
+
+  private subscribeToAllTopics(): void {
+    for (const pubSubTopic of this.pubSubTopics) {
+      this.gossipSubSubscribe(pubSubTopic);
+    }
   }
 
   private async processIncomingMessage<T extends IDecodedMessage>(
@@ -186,12 +206,20 @@ class Relay implements IRelay {
       return;
     }
 
-    const observers = this.observers.get(topicOnlyMsg.contentTopic) as Set<
+    // Retrieve the map of content topics for the given pubSubTopic
+    const contentTopicMap = this.observers.get(pubSubTopic);
+    if (!contentTopicMap) {
+      return;
+    }
+
+    // Retrieve the set of observers for the given contentTopic
+    const observers = contentTopicMap.get(topicOnlyMsg.contentTopic) as Set<
       Observer<T>
     >;
     if (!observers) {
       return;
     }
+
     await Promise.all(
       Array.from(observers).map(({ decoder, callback }) => {
         return (async () => {
@@ -241,7 +269,7 @@ class Relay implements IRelay {
   }
 
   private isRelayPubSub(pubsub: PubSub | undefined): boolean {
-    return pubsub?.multicodecs?.includes(Relay.multicodec) || false;
+    return pubsub?.multicodecs?.includes(Relay.multicodec) ?? false;
   }
 }
 
@@ -267,46 +295,3 @@ export function wakuGossipSub(
     return pubsub;
   };
 }
-
-function toObservers<T extends IDecodedMessage>(
-  decoders: IDecoder<T>[],
-  callback: Callback<T>
-): Map<ContentTopic, Set<Observer<T>>> {
-  const contentTopicToDecoders = Array.from(
-    groupByContentTopic(decoders).entries()
-  );
-
-  const contentTopicToObserversEntries = contentTopicToDecoders.map(
-    ([contentTopic, decoders]) =>
-      [
-        contentTopic,
-        new Set(
-          decoders.map(
-            (decoder) =>
-              ({
-                decoder,
-                callback
-              }) as Observer<T>
-          )
-        )
-      ] as [ContentTopic, Set<Observer<T>>]
-  );
-
-  return new Map(contentTopicToObserversEntries);
-}
-
-function union(left: Set<unknown>, right: Set<unknown>): Set<unknown> {
-  for (const val of right.values()) {
-    left.add(val);
-  }
-  return left;
-}
-
-function leftMinusJoin(left: Set<unknown>, right: Set<unknown>): Set<unknown> {
-  for (const val of right.values()) {
-    if (left.has(val)) {
-      left.delete(val);
-    }
-  }
-  return left;
-}

packages/relay/src/topic_only_message.ts

@@ -1,3 +1,4 @@
+import { DefaultPubSubTopic } from "@waku/core";
 import type {
   IDecodedMessage,
   IDecoder,
@@ -26,6 +27,7 @@ export class TopicOnlyMessage implements IDecodedMessage {
 }
 
 export class TopicOnlyDecoder implements IDecoder<TopicOnlyMessage> {
+  pubSubTopic = DefaultPubSubTopic;
   public contentTopic = "";
 
   fromWireToProtoObj(bytes: Uint8Array): Promise<IProtoMessage | undefined> {

packages/tests/tests/light-push/custom_pubsub.node.spec.ts

@@ -1,15 +1,11 @@
+import { createEncoder } from "@waku/core";
 import { LightNode } from "@waku/interfaces";
 import { utf8ToBytes } from "@waku/utils/bytes";
 import { expect } from "chai";
 
 import { MessageCollector, NimGoNode, tearDownNodes } from "../../src/index.js";
 
-import {
+import { messageText, runNodes, TestContentTopic } from "./utils.js";
-  messageText,
-  runNodes,
-  TestContentTopic,
-  TestEncoder
-} from "./utils.js";
 
 describe("Waku Light Push [node only] - custom pubsub topic", function () {
   this.timeout(15000);
@@ -36,7 +32,12 @@ describe("Waku Light Push [node only] - custom pubsub topic", function () {
   it("Push message", async function () {
     const nimPeerId = await nwaku.getPeerId();
 
-    const pushResponse = await waku.lightPush.send(TestEncoder, {
+    const testEncoder = createEncoder({
+      contentTopic: TestContentTopic,
+      pubSubTopic: customPubSubTopic
+    });
+
+    const pushResponse = await waku.lightPush.send(testEncoder, {
       payload: utf8ToBytes(messageText)
     });
 

packages/tests/tests/light-push/utils.ts

@@ -30,7 +30,7 @@ export async function runNodes(
   let waku: LightNode | undefined;
   try {
     waku = await createLightNode({
-      pubSubTopic,
+      pubSubTopics: pubSubTopic ? [pubSubTopic] : undefined,
       staticNoiseKey: NOISE_KEY_1
     });
     await waku.start();

packages/tests/tests/relay.node.spec.ts

@@ -259,6 +259,15 @@ describe("Waku Relay [node only]", () => {
     let waku1: RelayNode;
     let waku2: RelayNode;
     let waku3: RelayNode;
+
+    const pubSubTopic = "/some/pubsub/topic";
+
+    const CustomTopicEncoder = createEncoder({
+      contentTopic: TestContentTopic,
+      pubSubTopic: pubSubTopic
+    });
+    const CustomTopicDecoder = createDecoder(TestContentTopic, pubSubTopic);
+
     afterEach(async function () {
       !!waku1 &&
         waku1.stop().catch((e) => console.log("Waku failed to stop", e));
@@ -271,17 +280,15 @@ describe("Waku Relay [node only]", () => {
     it("Publish", async function () {
       this.timeout(10000);
 
-      const pubSubTopic = "/some/pubsub/topic";
-
       // 1 and 2 uses a custom pubsub
       // 3 uses the default pubsub
       [waku1, waku2, waku3] = await Promise.all([
         createRelayNode({
-          pubSubTopic: pubSubTopic,
+          pubSubTopics: [pubSubTopic],
           staticNoiseKey: NOISE_KEY_1
         }).then((waku) => waku.start().then(() => waku)),
         createRelayNode({
-          pubSubTopic: pubSubTopic,
+          pubSubTopics: [pubSubTopic],
           staticNoiseKey: NOISE_KEY_2,
           libp2p: { addresses: { listen: ["/ip4/0.0.0.0/tcp/0/ws"] } }
         }).then((waku) => waku.start().then(() => waku)),
@@ -310,7 +317,7 @@ describe("Waku Relay [node only]", () => {
 
       const waku2ReceivedMsgPromise: Promise<DecodedMessage> = new Promise(
         (resolve) => {
-          void waku2.relay.subscribe([TestDecoder], resolve);
+          void waku2.relay.subscribe([CustomTopicDecoder], resolve);
         }
       );
 
@@ -323,7 +330,7 @@ describe("Waku Relay [node only]", () => {
         }
       );
 
-      await waku1.relay.send(TestEncoder, {
+      await waku1.relay.send(CustomTopicEncoder, {
         payload: utf8ToBytes(messageText)
       });
 
@@ -338,16 +345,14 @@ describe("Waku Relay [node only]", () => {
       this.timeout(10000);
       const MB = 1024 ** 2;
 
-      const pubSubTopic = "/some/pubsub/topic";
-
       // 1 and 2 uses a custom pubsub
       [waku1, waku2] = await Promise.all([
         createRelayNode({
-          pubSubTopic: pubSubTopic,
+          pubSubTopics: [pubSubTopic],
           staticNoiseKey: NOISE_KEY_1
         }).then((waku) => waku.start().then(() => waku)),
         createRelayNode({
-          pubSubTopic: pubSubTopic,
+          pubSubTopics: [pubSubTopic],
           staticNoiseKey: NOISE_KEY_2,
           libp2p: { addresses: { listen: ["/ip4/0.0.0.0/tcp/0/ws"] } }
         }).then((waku) => waku.start().then(() => waku))
@@ -365,7 +370,7 @@ describe("Waku Relay [node only]", () => {
 
       const waku2ReceivedMsgPromise: Promise<DecodedMessage> = new Promise(
         (resolve) => {
-          void waku2.relay.subscribe([TestDecoder], () =>
+          void waku2.relay.subscribe([CustomTopicDecoder], () =>
             resolve({
               payload: new Uint8Array([])
             } as DecodedMessage)
@@ -373,18 +378,18 @@ describe("Waku Relay [node only]", () => {
         }
       );
 
-      let sendResult = await waku1.relay.send(TestEncoder, {
+      let sendResult = await waku1.relay.send(CustomTopicEncoder, {
         payload: generateRandomUint8Array(1 * MB)
       });
       expect(sendResult.recipients.length).to.eq(1);
 
-      sendResult = await waku1.relay.send(TestEncoder, {
+      sendResult = await waku1.relay.send(CustomTopicEncoder, {
         payload: generateRandomUint8Array(1 * MB + 65536)
       });
       expect(sendResult.recipients.length).to.eq(0);
       expect(sendResult.errors).to.include(SendError.SIZE_TOO_BIG);
 
-      sendResult = await waku1.relay.send(TestEncoder, {
+      sendResult = await waku1.relay.send(CustomTopicEncoder, {
         payload: generateRandomUint8Array(2 * MB)
       });
       expect(sendResult.recipients.length).to.eq(0);

packages/tests/tests/sharding.spec.ts

@@ -0,0 +1,79 @@
+import { createLightNode, LightNode, utf8ToBytes } from "@waku/sdk";
+import { createEncoder } from "@waku/sdk";
+import chai, { expect } from "chai";
+import chaiAsPromised from "chai-as-promised";
+
+import { makeLogFileName } from "../src/log_file.js";
+import { NimGoNode } from "../src/node/node.js";
+
+const PubSubTopic1 = "/waku/2/rs/0/2";
+const PubSubTopic2 = "/waku/2/rs/0/3";
+
+const ContentTopic = "/waku/2/content/test";
+
+chai.use(chaiAsPromised);
+
+describe("Static Sharding", () => {
+  let waku: LightNode;
+  let nwaku: NimGoNode;
+
+  beforeEach(async function () {
+    this.timeout(15_000);
+    nwaku = new NimGoNode(makeLogFileName(this));
+    await nwaku.start({ store: true, lightpush: true, relay: true });
+  });
+
+  afterEach(async function () {
+    !!nwaku &&
+      nwaku.stop().catch((e) => console.log("Nwaku failed to stop", e));
+    !!waku && waku.stop().catch((e) => console.log("Waku failed to stop", e));
+  });
+
+  it("configure the node with multiple pubsub topics", async function () {
+    this.timeout(15_000);
+    waku = await createLightNode({
+      pubSubTopics: [PubSubTopic1, PubSubTopic2]
+    });
+
+    const encoder1 = createEncoder({
+      contentTopic: ContentTopic,
+      pubSubTopic: PubSubTopic1
+    });
+
+    const encoder2 = createEncoder({
+      contentTopic: ContentTopic,
+      pubSubTopic: PubSubTopic2
+    });
+
+    const request1 = waku.lightPush.send(encoder1, {
+      payload: utf8ToBytes("Hello World")
+    });
+
+    const request2 = waku.lightPush.send(encoder2, {
+      payload: utf8ToBytes("Hello World")
+    });
+
+    await expect(request1).to.be.fulfilled;
+    await expect(request2).to.be.fulfilled;
+  });
+
+  it("using a protocol with unconfigured pubsub topic should fail", async function () {
+    this.timeout(15_000);
+    waku = await createLightNode({
+      pubSubTopics: [PubSubTopic1]
+    });
+
+    // use a pubsub topic that is not configured
+    const encoder = createEncoder({
+      contentTopic: ContentTopic,
+      pubSubTopic: PubSubTopic2
+    });
+
+    // the following request should throw an error
+    const request = waku.lightPush.send(encoder, {
+      payload: utf8ToBytes("Hello World")
+    });
+
+    await expect(request).to.be.rejectedWith(Error);
+  });
+});

packages/tests/tests/store.node.spec.ts

@@ -566,6 +566,11 @@ describe("Waku Store, custom pubsub topic", () => {
   let waku: LightNode;
   let nwaku: NimGoNode;
 
+  const CustomPubSubTestDecoder = createDecoder(
+    TestContentTopic,
+    customPubSubTopic
+  );
+
   beforeEach(async function () {
     this.timeout(15_000);
     nwaku = new NimGoNode(makeLogFileName(this));
@@ -600,7 +605,7 @@ describe("Waku Store, custom pubsub topic", () => {
 
     waku = await createLightNode({
       staticNoiseKey: NOISE_KEY_1,
-      pubSubTopic: customPubSubTopic
+      pubSubTopics: [customPubSubTopic]
     });
     await waku.start();
     await waku.dial(await nwaku.getMultiaddrWithId());
@@ -608,7 +613,9 @@ describe("Waku Store, custom pubsub topic", () => {
 
     const messages: IMessage[] = [];
     let promises: Promise<void>[] = [];
-    for await (const msgPromises of waku.store.queryGenerator([TestDecoder])) {
+    for await (const msgPromises of waku.store.queryGenerator([
+      CustomPubSubTestDecoder
+    ])) {
       const _promises = msgPromises.map(async (promise) => {
         const msg = await promise;
         if (msg) {

packages/tests/tests/wait_for_remote_peer.node.spec.ts

@@ -1,4 +1,4 @@
-import { waitForRemotePeer } from "@waku/core";
+import { DefaultPubSubTopic, waitForRemotePeer } from "@waku/core";
 import type { LightNode, RelayNode } from "@waku/interfaces";
 import { Protocols } from "@waku/interfaces";
 import { createLightNode, createRelayNode } from "@waku/sdk";
@@ -39,7 +39,7 @@ describe("Wait for remote peer", function () {
     await waku1.dial(multiAddrWithId);
     await delay(1000);
     await waitForRemotePeer(waku1, [Protocols.Relay]);
-    const peers = waku1.relay.getMeshPeers();
+    const peers = waku1.relay.getMeshPeers(DefaultPubSubTopic);
     const nimPeerId = multiAddrWithId.getPeerId();
 
     expect(nimPeerId).to.not.be.undefined;
@@ -262,7 +262,7 @@ describe("Wait for remote peer", function () {
     await waku1.dial(multiAddrWithId);
     await waitForRemotePeer(waku1);
 
-    const peers = waku1.relay.getMeshPeers();
+    const peers = waku1.relay.getMeshPeers(DefaultPubSubTopic);
 
     const nimPeerId = multiAddrWithId.getPeerId();
 

packages/utils/package.json

@@ -65,16 +65,16 @@
     "node": ">=18"
   },
   "dependencies": {
+    "chai": "^4.3.8",
     "debug": "^4.3.4",
-    "uint8arrays": "^4.0.4",
+    "uint8arrays": "^4.0.4"
-    "@waku/interfaces": "0.0.18"
   },
   "devDependencies": {
     "@rollup/plugin-commonjs": "^25.0.4",
     "@rollup/plugin-json": "^6.0.0",
     "@rollup/plugin-node-resolve": "^15.1.0",
     "@waku/build-utils": "*",
-    "@waku/interfaces": "0.0.17",
+    "@waku/interfaces": "0.0.18",
     "cspell": "^7.3.2",
     "npm-run-all": "^4.1.5",
     "rollup": "^3.29.2"

packages/utils/src/common/index.ts

@@ -3,6 +3,8 @@ export * from "./random_subset.js";
 export * from "./group_by.js";
 export * from "./to_async_iterator.js";
 export * from "./is_size_valid.js";
+export * from "./sharding.js";
+export * from "./push_or_init_map.js";
 
 export function removeItemFromArray(arr: unknown[], value: unknown): unknown[] {
   const index = arr.indexOf(value);

packages/utils/src/common/sharding.ts

@@ -0,0 +1,12 @@
+import type { PubSubTopic } from "@waku/interfaces";
+
+export function ensurePubsubTopicIsConfigured(
+  pubsubTopic: PubSubTopic,
+  configuredTopics: PubSubTopic[]
+): void {
+  if (!configuredTopics.includes(pubsubTopic)) {
+    throw new Error(
+      `PubSub topic ${pubsubTopic} has not been configured on this instance. Configured topics are: ${configuredTopics}. Please update your configuration by passing in the topic during Waku node instantiation.`
+    );
+  }
+}