diff --git a/packages/sdk/src/actor/behaviors/buttonBehavior.ts b/packages/sdk/src/actor/behaviors/buttonBehavior.ts
index 2a7a8a552..538a9ef50 100644
--- a/packages/sdk/src/actor/behaviors/buttonBehavior.ts
+++ b/packages/sdk/src/actor/behaviors/buttonBehavior.ts
@@ -8,9 +8,10 @@ import {
 	ActionState,
 	BehaviorType,
 	DiscreteAction,
-	TargetBehavior,
 	User
 } from '../..';
+// break import cycle
+import { TargetBehavior } from './targetBehavior';
 
 /**
  * Button behavior class containing the target behavior actions.
diff --git a/packages/sdk/src/actor/behaviors/targetBehavior.ts b/packages/sdk/src/actor/behaviors/targetBehavior.ts
index 724d5860b..bceb4bdaa 100644
--- a/packages/sdk/src/actor/behaviors/targetBehavior.ts
+++ b/packages/sdk/src/actor/behaviors/targetBehavior.ts
@@ -6,11 +6,12 @@
 import {
 	ActionHandler,
 	ActionState,
-	Behavior,
 	BehaviorType,
 	DiscreteAction,
 	User
 } from '../..';
+// break import cycle
+import { Behavior } from './behavior';
 
 /**
  * Target behavior class containing the target behavior actions.
diff --git a/packages/sdk/src/asset/material.ts b/packages/sdk/src/asset/material.ts
index 3b3788b89..b317145b8 100644
--- a/packages/sdk/src/asset/material.ts
+++ b/packages/sdk/src/asset/material.ts
@@ -5,7 +5,6 @@
 
 import {
 	Actor,
-	Asset,
 	AssetContainer,
 	AssetLike,
 	Color3,
@@ -22,6 +21,8 @@ import {
 	readPath
 } from '../internal';
 import { AssetInternal } from './assetInternal';
+// break import cycle
+import { Asset } from './asset';
 
 /**
  * Describes the properties of a Material.
diff --git a/packages/sdk/src/asset/mesh.ts b/packages/sdk/src/asset/mesh.ts
index 3ffaa0222..f1300b3c1 100644
--- a/packages/sdk/src/asset/mesh.ts
+++ b/packages/sdk/src/asset/mesh.ts
@@ -5,7 +5,6 @@
 
 import {
 	Actor,
-	Asset,
 	AssetContainer,
 	AssetLike,
 	PrimitiveDefinition,
@@ -14,6 +13,8 @@ import {
 } from '..';
 import { Patchable } from '../internal';
 import { AssetInternal } from './assetInternal';
+// break import cycle
+import { Asset } from './asset';
 
 /** Describes the properties of a mesh */
 export interface MeshLike {
diff --git a/packages/sdk/src/asset/prefab.ts b/packages/sdk/src/asset/prefab.ts
index f3daa42ef..705c23840 100644
--- a/packages/sdk/src/asset/prefab.ts
+++ b/packages/sdk/src/asset/prefab.ts
@@ -3,9 +3,11 @@
  * Licensed under the MIT License.
  */
 
-import { Actor, Asset, AssetContainer, AssetLike } from '..';
+import { Actor, AssetContainer, AssetLike } from '..';
 import { Patchable } from '../internal';
 import { AssetInternal } from './assetInternal';
+// break import cycle
+import { Asset } from './asset';
 
 export interface PrefabLike {
 	/** The number of actors this prefab contains. */
diff --git a/packages/sdk/src/asset/sound.ts b/packages/sdk/src/asset/sound.ts
index 10ea14d05..e4820e515 100644
--- a/packages/sdk/src/asset/sound.ts
+++ b/packages/sdk/src/asset/sound.ts
@@ -3,9 +3,11 @@
  * Licensed under the MIT License.
  */
 
-import { Actor, Asset, AssetContainer, AssetLike } from '..';
+import { Actor, AssetContainer, AssetLike } from '..';
 import { Patchable } from '../internal';
 import { AssetInternal } from './assetInternal';
+// break import cycle
+import { Asset } from './asset';
 
 export interface SoundLike {
 	uri: string;
diff --git a/packages/sdk/src/asset/texture.ts b/packages/sdk/src/asset/texture.ts
index a8c2cba7a..78ae617e5 100644
--- a/packages/sdk/src/asset/texture.ts
+++ b/packages/sdk/src/asset/texture.ts
@@ -3,9 +3,11 @@
  * Licensed under the MIT License.
  */
 
-import { Actor, Asset, AssetContainer, AssetLike, Material, Vector2, Vector2Like } from '..';
+import { Actor, AssetContainer, AssetLike, Material, Vector2, Vector2Like } from '..';
 import { Patchable, readPath } from '../internal';
 import { AssetInternal } from './assetInternal';
+// break import cycle
+import { Asset } from './asset';
 
 export interface TextureLike {
 	uri: string;
diff --git a/packages/sdk/src/asset/videoStream.ts b/packages/sdk/src/asset/videoStream.ts
index 6d71e9ae9..b29c8e0d1 100644
--- a/packages/sdk/src/asset/videoStream.ts
+++ b/packages/sdk/src/asset/videoStream.ts
@@ -3,9 +3,11 @@
  * Licensed under the MIT License.
  */
 
-import { Actor, Asset, AssetContainer, AssetLike } from '..';
+import { Actor, AssetContainer, AssetLike } from '..';
 import { Patchable } from '../internal';
 import { AssetInternal } from './assetInternal';
+// break import cycle
+import { Asset } from './asset';
 
 export interface VideoStreamLike {
 	uri: string;
diff --git a/packages/sdk/src/internal/adapters/multipeer/protocols/clientExecution.ts b/packages/sdk/src/internal/adapters/multipeer/protocols/clientExecution.ts
index 0c1d86518..6eed16996 100644
--- a/packages/sdk/src/internal/adapters/multipeer/protocols/clientExecution.ts
+++ b/packages/sdk/src/internal/adapters/multipeer/protocols/clientExecution.ts
@@ -9,16 +9,17 @@ import {
 	ExportedPromise,
 	Message,
 	MissingRule,
-	Protocols,
 	Rules
 } from '../../..';
+// break import cycle
+import { Heartbeat, Middleware, Protocol, ServerPreprocessing } from '../../../protocols';
 
 /**
  * @hidden
  * Class for routing messages between the client and the session
  */
-export class ClientExecution extends Protocols.Protocol implements Protocols.Middleware {
-	private heartbeat: Protocols.Heartbeat;
+export class ClientExecution extends Protocol implements Middleware {
+	private heartbeat: Heartbeat;
 	private heartbeatTimer: NodeJS.Timer;
 
 	/** @override */
@@ -26,10 +27,10 @@ export class ClientExecution extends Protocols.Protocol implements Protocols.Mid
 
 	constructor(private client: Client) {
 		super(client.conn);
-		this.heartbeat = new Protocols.Heartbeat(this);
+		this.heartbeat = new Heartbeat(this);
 		this.beforeRecv = this.beforeRecv.bind(this);
 		// Behave like a server-side endpoint (send heartbeats, measure connection quality)
-		this.use(new Protocols.ServerPreprocessing());
+		this.use(new ServerPreprocessing());
 		// Filter user-exclusive actors
 		this.use(new ClientDesyncPreprocessor(client));
 		// Use middleware to pipe client messages to the session.
diff --git a/packages/sdk/src/internal/adapters/multipeer/protocols/clientHandshake.ts b/packages/sdk/src/internal/adapters/multipeer/protocols/clientHandshake.ts
index 368a48d5e..a32216541 100644
--- a/packages/sdk/src/internal/adapters/multipeer/protocols/clientHandshake.ts
+++ b/packages/sdk/src/internal/adapters/multipeer/protocols/clientHandshake.ts
@@ -9,14 +9,15 @@ import {
 	Message,
 	MissingRule,
 	OperatingModel,
-	Protocols,
 	Rules
 } from '../../..';
+// break import cycle
+import { Handshake } from '../../../protocols';
 
 /**
  * @hidden
  */
-export class ClientHandshake extends Protocols.Handshake {
+export class ClientHandshake extends Handshake {
 	/** @override */
 	public get name(): string { return `${this.constructor.name} client ${this.client.id.substr(0, 8)}`; }
 
diff --git a/packages/sdk/src/internal/adapters/multipeer/protocols/clientStartup.ts b/packages/sdk/src/internal/adapters/multipeer/protocols/clientStartup.ts
index 66e92f680..0136f3142 100644
--- a/packages/sdk/src/internal/adapters/multipeer/protocols/clientStartup.ts
+++ b/packages/sdk/src/internal/adapters/multipeer/protocols/clientStartup.ts
@@ -9,18 +9,19 @@ import {
 	Message,
 	MissingRule,
 	Payloads,
-	Protocols,
 	Rules
 } from '../../..';
+// break import cycle
+import { Heartbeat, Protocol, ServerPreprocessing } from '../../../protocols';
 
-export class ClientStartup extends Protocols.Protocol {
+export class ClientStartup extends Protocol {
 	/** @override */
 	public get name(): string { return `${this.constructor.name} client ${this.client.id.substr(0, 8)}`; }
 
 	constructor(private client: Client, syncRequest: Payloads.SyncRequest) {
 		super(client.conn);
 		// Behave like a server-side endpoint (send heartbeats, measure connection quality).
-		this.use(new Protocols.ServerPreprocessing());
+		this.use(new ServerPreprocessing());
 		// If we've already received the 'sync-request' payload, process it now.
 		if (syncRequest) {
 			setImmediate(async () => {
@@ -45,7 +46,7 @@ export class ClientStartup extends Protocols.Protocol {
 
 	private async performStartup(payload: Payloads.SyncRequest) {
 		// Do a quick measurement of connection latency.
-		const heartbeat = new Protocols.Heartbeat(this);
+		const heartbeat = new Heartbeat(this);
 		await heartbeat.runIterations(10); // Allow exceptions to propagate out.
 		this.resolve();
 	}
diff --git a/packages/sdk/src/internal/adapters/multipeer/protocols/clientSync.ts b/packages/sdk/src/internal/adapters/multipeer/protocols/clientSync.ts
index 2296ee707..c30aeb7b4 100644
--- a/packages/sdk/src/internal/adapters/multipeer/protocols/clientSync.ts
+++ b/packages/sdk/src/internal/adapters/multipeer/protocols/clientSync.ts
@@ -14,10 +14,11 @@ import {
 	Message,
 	MissingRule,
 	Payloads,
-	Protocols,
 	Rules,
 	SyncActor
 } from '../../../../internal';
+// break import cycle
+import { Protocol, ServerPreprocessing } from '../../../protocols';
 
 /**
  * @hidden
@@ -36,7 +37,7 @@ export type SynchronizationStage =
  * @hidden
  * Synchronizes application state with a client.
  */
-export class ClientSync extends Protocols.Protocol {
+export class ClientSync extends Protocol {
 	private inProgressStages: SynchronizationStage[] = [];
 	private completedStages: SynchronizationStage[] = [];
 
@@ -56,7 +57,7 @@ export class ClientSync extends Protocols.Protocol {
 	constructor(private client: Client) {
 		super(client.conn);
 		// Behave like a server-side endpoint (send heartbeats, measure connection quality)
-		this.use(new Protocols.ServerPreprocessing());
+		this.use(new ServerPreprocessing());
 		// Queue up user-exclusive messages until the user has joined
 		this.use(new ClientDesyncPreprocessor(client));
 	}
diff --git a/packages/sdk/src/internal/adapters/multipeer/protocols/sessionExecution.ts b/packages/sdk/src/internal/adapters/multipeer/protocols/sessionExecution.ts
index fbf5cc86f..934c1aa51 100644
--- a/packages/sdk/src/internal/adapters/multipeer/protocols/sessionExecution.ts
+++ b/packages/sdk/src/internal/adapters/multipeer/protocols/sessionExecution.ts
@@ -3,18 +3,20 @@
  * Licensed under the MIT License.
  */
 
-import { Message, Protocols, Session } from '../../../../internal';
+import { Message, Session } from '../../../../internal';
+// break import cycle
+import { Middleware, Protocol, ClientPreprocessing } from '../../../protocols';
 
 /**
  * @hidden
  * Class for routing messages from the app over to the session
  */
-export class SessionExecution extends Protocols.Protocol implements Protocols.Middleware {
+export class SessionExecution extends Protocol implements Middleware {
 	constructor(private session: Session) {
 		super(session.conn);
 		this.beforeRecv = this.beforeRecv.bind(this);
 		// Behave like a client-side endpoint (record latency, respond to heartbeats).
-		this.use(new Protocols.ClientPreprocessing(this));
+		this.use(new ClientPreprocessing(this));
 		// Use middleware to take incoming messages from the app and pipe them to the session.
 		this.use(this);
 	}
diff --git a/packages/sdk/src/internal/adapters/multipeer/protocols/sessionHandshake.ts b/packages/sdk/src/internal/adapters/multipeer/protocols/sessionHandshake.ts
index a541bfa84..e93256da0 100644
--- a/packages/sdk/src/internal/adapters/multipeer/protocols/sessionHandshake.ts
+++ b/packages/sdk/src/internal/adapters/multipeer/protocols/sessionHandshake.ts
@@ -3,17 +3,19 @@
  * Licensed under the MIT License.
  */
 
-import { Payloads, Protocols, Session } from '../../../../internal';
+import { Payloads, Session } from '../../../../internal';
+// break import cycle
+import { Protocol, ClientPreprocessing } from '../../../protocols';
 
 /**
  * @hidden
  * Protocol for handling handshake with the app instance (Session is a client of App)
  */
-export class SessionHandshake extends Protocols.Protocol {
+export class SessionHandshake extends Protocol {
 	constructor(session: Session) {
 		super(session.conn);
 		// Behave like a client-side endpoint (record latency, respond to heartbeats).
-		this.use(new Protocols.ClientPreprocessing(this));
+		this.use(new ClientPreprocessing(this));
 	}
 
 	/** @override */
diff --git a/packages/sdk/src/internal/adapters/multipeer/protocols/sessionSync.ts b/packages/sdk/src/internal/adapters/multipeer/protocols/sessionSync.ts
index 829a479e5..ab99fda9a 100644
--- a/packages/sdk/src/internal/adapters/multipeer/protocols/sessionSync.ts
+++ b/packages/sdk/src/internal/adapters/multipeer/protocols/sessionSync.ts
@@ -3,17 +3,19 @@
  * Licensed under the MIT License.
  */
 
-import { Payloads, Protocols, Session } from '../../../../internal';
+import { Payloads, Session } from '../../../../internal';
+// break import cycle
+import { Protocol, ClientPreprocessing } from '../../../protocols';
 
 /**
  * @hidden
  * Class to manage the synchronization phase when connecting to the app. There should be no state to synchronize
  */
-export class SessionSync extends Protocols.Protocol {
+export class SessionSync extends Protocol {
 	constructor(session: Session) {
 		super(session.conn);
 		// Behave like a client-side endpoint (record latency, respond to heartbeats).
-		this.use(new Protocols.ClientPreprocessing(this));
+		this.use(new ClientPreprocessing(this));
 	}
 
 	/** @override */
diff --git a/packages/sdk/src/internal/connection/eventedConnection.ts b/packages/sdk/src/internal/connection/eventedConnection.ts
index a42e0eb9d..64b30c9fc 100644
--- a/packages/sdk/src/internal/connection/eventedConnection.ts
+++ b/packages/sdk/src/internal/connection/eventedConnection.ts
@@ -6,13 +6,14 @@
 import { EventEmitter } from 'events';
 import { Guid } from '../..';
 import {
-	Connection,
 	ConnectionQuality,
 	Message,
 	NetworkStatsReport,
 	NetworkStatsTracker,
 	QueuedPromise
 } from '../../internal';
+// break import cycle
+import { Connection } from './connection';
 
 /**
  * @hidden
diff --git a/packages/sdk/src/internal/connection/webSocket.ts b/packages/sdk/src/internal/connection/webSocket.ts
index 01ac4e05d..66e5b1a0c 100644
--- a/packages/sdk/src/internal/connection/webSocket.ts
+++ b/packages/sdk/src/internal/connection/webSocket.ts
@@ -6,7 +6,9 @@
 import * as WS from 'ws';
 
 import { log } from '../..';
-import { EventedConnection, filterEmpty, Message, validateJsonFieldName } from '../../internal';
+import { filterEmpty, Message, validateJsonFieldName } from '../../internal';
+// break import cycle
+import { EventedConnection } from './eventedConnection';
 
 /**
  * An implementation of the Connection interface that wraps a WebSocket.
diff --git a/packages/sdk/src/internal/protocols/execution.ts b/packages/sdk/src/internal/protocols/execution.ts
index fe7946660..84169846d 100644
--- a/packages/sdk/src/internal/protocols/execution.ts
+++ b/packages/sdk/src/internal/protocols/execution.ts
@@ -4,17 +4,21 @@
  */
 
 import { ActionEvent, CollisionEvent, Context, log, TriggerEvent, } from '../..';
-import { Message, Payloads, Protocols, WebSocket } from '../../internal';
+import { Message, Payloads, WebSocket } from '../../internal';
+// break import cycle
+import { Protocol } from './protocol';
+import { ServerPreprocessing } from './serverPreprocessing';
+import { Sync } from './sync';
 
 /**
  * @hidden
  * Class to handle operational messages with a client.
  */
-export class Execution extends Protocols.Protocol {
+export class Execution extends Protocol {
 	constructor(private context: Context) {
 		super(context.conn);
 		// Behave like a server-side endpoint (send heartbeats, measure connection quality)
-		this.use(new Protocols.ServerPreprocessing());
+		this.use(new ServerPreprocessing());
 	}
 
 	/** @override */
@@ -94,7 +98,7 @@ export class Execution extends Protocols.Protocol {
 		// Switch over to the Sync protocol to handle this request
 		this.stopListening();
 
-		const sync = new Protocols.Sync(this.conn);
+		const sync = new Sync(this.conn);
 		await sync.run(); // Allow exception to propagate.
 
 		this.startListening();
diff --git a/packages/sdk/src/internal/protocols/handshake.ts b/packages/sdk/src/internal/protocols/handshake.ts
index acfee75b6..2d1fddb46 100644
--- a/packages/sdk/src/internal/protocols/handshake.ts
+++ b/packages/sdk/src/internal/protocols/handshake.ts
@@ -3,19 +3,22 @@
  * Licensed under the MIT License.
  */
 
-import { Connection, OperatingModel, Payloads, Protocols } from '../../internal';
+import { Connection, OperatingModel, Payloads } from '../../internal';
+// break import cycle
+import { Protocol } from './protocol';
+import { ServerPreprocessing } from './serverPreprocessing';
 
 /**
  * @hidden
  * Class to manage the handshake process with a client.
  */
-export class Handshake extends Protocols.Protocol {
+export class Handshake extends Protocol {
 	public syncRequest: Payloads.SyncRequest;
 
 	constructor(conn: Connection, private sessionId: string, private operatingModel: OperatingModel) {
 		super(conn);
 		// Behave like a server-side endpoint (send heartbeats, measure connection quality)
-		this.use(new Protocols.ServerPreprocessing());
+		this.use(new ServerPreprocessing());
 	}
 
 	/** @private */
diff --git a/packages/sdk/src/internal/protocols/sync.ts b/packages/sdk/src/internal/protocols/sync.ts
index 2cc53e75c..204b829a2 100644
--- a/packages/sdk/src/internal/protocols/sync.ts
+++ b/packages/sdk/src/internal/protocols/sync.ts
@@ -3,17 +3,20 @@
  * Licensed under the MIT License.
  */
 
-import { Connection, Payloads, Protocols } from '../../internal';
+import { Connection, Payloads } from '../../internal';
+// break import cycle
+import { Protocol } from './protocol';
+import { ServerPreprocessing } from './serverPreprocessing';
 
 /**
  * @hidden
  * Class to manage the join process with a client.
  */
-export class Sync extends Protocols.Protocol {
+export class Sync extends Protocol {
 	constructor(conn: Connection) {
 		super(conn);
 		// Behave like a server-side endpoint (send heartbeats, measure connection quality)
-		this.use(new Protocols.ServerPreprocessing());
+		this.use(new ServerPreprocessing());
 	}
 
 	/** @override */
diff --git a/packages/sdk/src/internal/util/verifyClient.ts b/packages/sdk/src/internal/util/verifyClient.ts
index 878f0122e..60936d42f 100644
--- a/packages/sdk/src/internal/util/verifyClient.ts
+++ b/packages/sdk/src/internal/util/verifyClient.ts
@@ -10,7 +10,7 @@ import { log } from '../..';
 /*
  * Current SDK Version - Read from package.json.
  */
-const CurrentSDKVersion = semver.coerce(require('../../package.json').version);
+const CurrentSDKVersion = semver.coerce(require('../../../package.json').version);
 
 /*
  * Minimum Supported Client Library version
diff --git a/packages/sdk/src/util/webHost.ts b/packages/sdk/src/util/webHost.ts
index 3d9e058e0..e4541f2ff 100644
--- a/packages/sdk/src/util/webHost.ts
+++ b/packages/sdk/src/util/webHost.ts
@@ -30,7 +30,7 @@ export class WebHost {
 		baseUrl?: string;
 		port?: string | number;
 	} = {}) {
-		const pjson = require('../package.json'); /* eslint-disable-line @typescript-eslint/no-var-requires */
+		const pjson = require('../../package.json'); /* eslint-disable-line @typescript-eslint/no-var-requires */
 		log.info('app', `Node: ${process.version}`);
 		log.info('app', `${pjson.name}: v${pjson.version}`);