diff --git a/src/common/architecture/scripts/nodeWatcher/LegacyNodeWatcherScript.ts b/src/common/architecture/scripts/nodeWatcher/LegacyNodeWatcherScript.ts
index b4c07a5..211210d 100644
--- a/src/common/architecture/scripts/nodeWatcher/LegacyNodeWatcherScript.ts
+++ b/src/common/architecture/scripts/nodeWatcher/LegacyNodeWatcherScript.ts
@@ -1,4 +1,4 @@
-import NodeWatcherSingleton from '../../../nodeWatcher/NodeWatcher';
+import NodeWatcherSingleton, { NodeWatcherAdapter } from '../../../../infrastructure/presentation/nodeWatcher/NodeWatcher.adapter';
 import { ConcreteNodeWatcherScriptHandler } from './handlers/NodeWatcherScriptHandler';
 import Script from '../Script';
 
@@ -11,22 +11,28 @@
     ConcreteNodeWatcherScriptHandler<Options>
   >;
 
+  private nodeWatcher: NodeWatcherAdapter;
+
+  constructor() {
+    super();
+
+    // TODO(https://iavm.xyz/b/226): Retrieve this via constructor injection.
+    this.nodeWatcher = NodeWatcherSingleton.getInstance();
+  }
+
   /**
    * Resolves to the options when the script is executed.
    *
-   * This is so we can defer retrieving dependencies until the script is
-   * executed, to prevent loading unnecessary things if they aren't needed
-   * after all.
    */
   protected abstract optionsFactory(): Options;
 
   execute() {
-    const nodeWatcher = NodeWatcherSingleton.getInstance();
     const options = this.optionsFactory();
 
+    this.nodeWatcher.start();
     for (const [key, handlerClass] of this.handlers) {
       const handler = new handlerClass(options);
-      nodeWatcher.setHandler(key, handler);
+      this.nodeWatcher.setHandler(key, handler);
     }
   }
 }
diff --git a/src/common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler.ts b/src/common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler.ts
index b5c3698..8756b72 100644
--- a/src/common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler.ts
+++ b/src/common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler.ts
@@ -1,5 +1,5 @@
 import { NodeWatcherScriptHandler } from './NodeWatcherScriptHandler';
-import { NodeMutation, NodeMutationType } from '../../../../nodeWatcher/NodeWatcherHandler';
+import { NodeMutation, NodeMutationType } from '../../../../../presentation/nodeWatcher/NodeWatcherHandler';
 
 /**
  * @deprecated
diff --git a/src/common/architecture/scripts/nodeWatcher/handlers/NodeWatcherScriptHandler.ts b/src/common/architecture/scripts/nodeWatcher/handlers/NodeWatcherScriptHandler.ts
index 5b0fd42..712f533 100644
--- a/src/common/architecture/scripts/nodeWatcher/handlers/NodeWatcherScriptHandler.ts
+++ b/src/common/architecture/scripts/nodeWatcher/handlers/NodeWatcherScriptHandler.ts
@@ -1,4 +1,4 @@
-import { NodeMutation, NodeWatcherHandler } from "../../../../nodeWatcher/NodeWatcherHandler";
+import { NodeMutation, NodeWatcherHandler } from "../../../../../presentation/nodeWatcher/NodeWatcherHandler";
 
 export abstract class NodeWatcherScriptHandler<Options>
   implements NodeWatcherHandler
diff --git a/src/features/autoRefresh/nodeWatcherHandlers/threadListHide.handler.ts b/src/features/autoRefresh/nodeWatcherHandlers/threadListHide.handler.ts
index d0a41de..9712c00 100644
--- a/src/features/autoRefresh/nodeWatcherHandlers/threadListHide.handler.ts
+++ b/src/features/autoRefresh/nodeWatcherHandlers/threadListHide.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutationType } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutationType } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { AutoRefreshNodeWatcherDependencies } from '../scripts/nodeWatcher.script';
 
 /**
diff --git a/src/features/ccDarkTheme/nodeWatcherHandlers/ecApp.handler.ts b/src/features/ccDarkTheme/nodeWatcherHandlers/ecApp.handler.ts
index 12d50bb..fee1ffd 100644
--- a/src/features/ccDarkTheme/nodeWatcherHandlers/ecApp.handler.ts
+++ b/src/features/ccDarkTheme/nodeWatcherHandlers/ecApp.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { injectDarkThemeButton } from '../core/logic/darkTheme';
 import { CCDarkThemeNodeWatcherDependencies } from '../scripts/nodeWatcher.script';
 
diff --git a/src/features/ccDarkTheme/nodeWatcherHandlers/reportDialog.handler.ts b/src/features/ccDarkTheme/nodeWatcherHandlers/reportDialog.handler.ts
index 83942e5..42c7a59 100644
--- a/src/features/ccDarkTheme/nodeWatcherHandlers/reportDialog.handler.ts
+++ b/src/features/ccDarkTheme/nodeWatcherHandlers/reportDialog.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { CCDarkThemeNodeWatcherDependencies } from '../scripts/nodeWatcher.script';
 
 /**
diff --git a/src/features/ccDarkTheme/nodeWatcherHandlers/unifiedProfilesIframe.handler.ts b/src/features/ccDarkTheme/nodeWatcherHandlers/unifiedProfilesIframe.handler.ts
index b71b9a7..6343834 100644
--- a/src/features/ccDarkTheme/nodeWatcherHandlers/unifiedProfilesIframe.handler.ts
+++ b/src/features/ccDarkTheme/nodeWatcherHandlers/unifiedProfilesIframe.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { isDarkThemeOn } from '../core/logic/darkTheme';
 import { unifiedProfilesFix } from '../core/logic/unifiedProfiles';
 import { CCDarkThemeNodeWatcherDependencies } from '../scripts/nodeWatcher.script';
diff --git a/src/features/extraInfo/nodeWatcherHandlers/profile/ccExtraInfoProfileAbuseChips.handler.ts b/src/features/extraInfo/nodeWatcherHandlers/profile/ccExtraInfoProfileAbuseChips.handler.ts
index 7cc895a..482a456 100644
--- a/src/features/extraInfo/nodeWatcherHandlers/profile/ccExtraInfoProfileAbuseChips.handler.ts
+++ b/src/features/extraInfo/nodeWatcherHandlers/profile/ccExtraInfoProfileAbuseChips.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { CCExtraInfoMainOptions } from '../../scripts/ccExtraInfoMain.script';
 
 export default class CCExtraInfoProfileAbuseChipsHandler extends CssSelectorNodeWatcherScriptHandler<CCExtraInfoMainOptions> {
diff --git a/src/features/extraInfo/nodeWatcherHandlers/profile/ccExtraInfoProfilePerForumStats.handler.ts b/src/features/extraInfo/nodeWatcherHandlers/profile/ccExtraInfoProfilePerForumStats.handler.ts
index d08db21..bd2bb1c 100644
--- a/src/features/extraInfo/nodeWatcherHandlers/profile/ccExtraInfoProfilePerForumStats.handler.ts
+++ b/src/features/extraInfo/nodeWatcherHandlers/profile/ccExtraInfoProfilePerForumStats.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { CCExtraInfoMainOptions } from '../../scripts/ccExtraInfoMain.script';
 
 export default class CCExtraInfoProfilePerForumStatsHandler extends CssSelectorNodeWatcherScriptHandler<CCExtraInfoMainOptions> {
diff --git a/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadComment.handler.ts b/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadComment.handler.ts
index 802dc51..5527e1a 100644
--- a/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadComment.handler.ts
+++ b/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadComment.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { CCExtraInfoMainOptions } from '../../scripts/ccExtraInfoMain.script';
 
 /**
diff --git a/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadQuestion.handler.ts b/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadQuestion.handler.ts
index 0d16772..028b9a3 100644
--- a/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadQuestion.handler.ts
+++ b/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadQuestion.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { CCExtraInfoMainOptions } from '../../scripts/ccExtraInfoMain.script';
 
 /**
diff --git a/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadReply.handler.ts b/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadReply.handler.ts
index 543ddb0..94ad753 100644
--- a/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadReply.handler.ts
+++ b/src/features/extraInfo/nodeWatcherHandlers/thread/ccExtraInfoThreadReply.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { CCExtraInfoMainOptions } from '../../scripts/ccExtraInfoMain.script';
 
 /**
diff --git a/src/features/extraInfo/nodeWatcherHandlers/threadList/ccExtraInfoThreadList.handler.ts b/src/features/extraInfo/nodeWatcherHandlers/threadList/ccExtraInfoThreadList.handler.ts
index 5d26037..d2e7008 100644
--- a/src/features/extraInfo/nodeWatcherHandlers/threadList/ccExtraInfoThreadList.handler.ts
+++ b/src/features/extraInfo/nodeWatcherHandlers/threadList/ccExtraInfoThreadList.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { CCExtraInfoMainOptions } from '../../scripts/ccExtraInfoMain.script';
 
 /**
diff --git a/src/features/extraInfo/nodeWatcherHandlers/threadList/ccExtraInfoThreadListToolbelt.handler.ts b/src/features/extraInfo/nodeWatcherHandlers/threadList/ccExtraInfoThreadListToolbelt.handler.ts
index b6ef4dc..d28f6f8 100644
--- a/src/features/extraInfo/nodeWatcherHandlers/threadList/ccExtraInfoThreadListToolbelt.handler.ts
+++ b/src/features/extraInfo/nodeWatcherHandlers/threadList/ccExtraInfoThreadListToolbelt.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { CCExtraInfoMainOptions } from '../../scripts/ccExtraInfoMain.script';
 
 /**
diff --git a/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollLoadMoreBar.handler.ts b/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollLoadMoreBar.handler.ts
index e9f04ff..5c2d308 100644
--- a/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollLoadMoreBar.handler.ts
+++ b/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollLoadMoreBar.handler.ts
@@ -1,4 +1,4 @@
-import { NodeMutation } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import CssSelectorNodeWatcherScriptHandler from '../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
 import { InfiniteScrollNodeWatcherOptions } from '../scripts/ccInfiniteScroll.script';
 
diff --git a/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollLoadMoreBtn.handler.ts b/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollLoadMoreBtn.handler.ts
index 8bf6fd2..1ab8644 100644
--- a/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollLoadMoreBtn.handler.ts
+++ b/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollLoadMoreBtn.handler.ts
@@ -1,4 +1,4 @@
-import { NodeMutation } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import CssSelectorNodeWatcherScriptHandler from '../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
 import { InfiniteScrollNodeWatcherOptions } from '../scripts/ccInfiniteScroll.script';
 
diff --git a/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollSetUp.handler.ts b/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollSetUp.handler.ts
index 60331a0..b36e0b9 100644
--- a/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollSetUp.handler.ts
+++ b/src/features/infiniteScroll/nodeWatcherHandlers/ccInfiniteScrollSetUp.handler.ts
@@ -1,4 +1,4 @@
-import { NodeMutation } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import CssSelectorNodeWatcherScriptHandler from '../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
 import { InfiniteScrollNodeWatcherOptions } from '../scripts/ccInfiniteScroll.script';
 
diff --git a/src/features/workflows/nodeWatcherHandlers/crTags.handler.ts b/src/features/workflows/nodeWatcherHandlers/crTags.handler.ts
index fbaee19..040c5ed 100644
--- a/src/features/workflows/nodeWatcherHandlers/crTags.handler.ts
+++ b/src/features/workflows/nodeWatcherHandlers/crTags.handler.ts
@@ -1,5 +1,5 @@
 import CssSelectorNodeWatcherScriptHandler from '../../../common/architecture/scripts/nodeWatcher/handlers/CssSelectorNodeWatcherScriptHandler';
-import { NodeMutation } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { WorkflowsNodeWatcherDependencies } from '../scripts/nodeWatcher.script';
 
 /**
diff --git a/src/features/workflows/nodeWatcherHandlers/threadListActionBar.handler.ts b/src/features/workflows/nodeWatcherHandlers/threadListActionBar.handler.ts
index ff62487..ab23f11 100644
--- a/src/features/workflows/nodeWatcherHandlers/threadListActionBar.handler.ts
+++ b/src/features/workflows/nodeWatcherHandlers/threadListActionBar.handler.ts
@@ -1,5 +1,5 @@
 import { NodeWatcherScriptHandler } from '../../../common/architecture/scripts/nodeWatcher/handlers/NodeWatcherScriptHandler';
-import { NodeMutation } from '../../../common/nodeWatcher/NodeWatcherHandler';
+import { NodeMutation } from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 import { WorkflowsNodeWatcherDependencies } from '../scripts/nodeWatcher.script';
 
 /**
diff --git a/src/common/nodeWatcher/NodeWatcher.ts b/src/infrastructure/presentation/nodeWatcher/NodeWatcher.adapter.ts
similarity index 85%
rename from src/common/nodeWatcher/NodeWatcher.ts
rename to src/infrastructure/presentation/nodeWatcher/NodeWatcher.adapter.ts
index 73b9560..0d46e47 100644
--- a/src/common/nodeWatcher/NodeWatcher.ts
+++ b/src/infrastructure/presentation/nodeWatcher/NodeWatcher.adapter.ts
@@ -2,20 +2,20 @@
   NodeWatcherHandler,
   NodeMutation,
   NodeMutationType,
-} from './NodeWatcherHandler';
+} from '../../../presentation/nodeWatcher/NodeWatcherHandler';
 
-class NodeWatcher {
+export class NodeWatcherAdapter {
+  private started = false;
   private handlers: Map<string, NodeWatcherHandler> = new Map();
-  private mutationObserver: MutationObserver;
+  private mutationObserver: MutationObserver | undefined;
 
-  constructor() {
+  start(): void {
+    if (this.started) return;
+
+    this.started = true;
     this.mutationObserver = new MutationObserver(
       this.mutationCallback.bind(this),
     );
-    this.start();
-  }
-
-  start(): void {
     this.mutationObserver.observe(document.body, {
       childList: true,
       subtree: true,
@@ -27,6 +27,7 @@
   }
 
   setHandler(key: string, handler: NodeWatcherHandler): void {
+    this.start();
     this.handlers.set(key, handler);
     this.performInitialDiscovery(handler);
   }
@@ -97,16 +98,16 @@
 }
 
 export default class NodeWatcherSingleton {
-  private static instance: NodeWatcher;
+  private static instance: NodeWatcherAdapter;
 
   /**
    * @see {@link NodeWatcherSingleton.getInstance}
    */
   private constructor() {}
 
-  public static getInstance(): NodeWatcher {
+  public static getInstance(): NodeWatcherAdapter {
     if (!NodeWatcherSingleton.instance) {
-      NodeWatcherSingleton.instance = new NodeWatcher();
+      NodeWatcherSingleton.instance = new NodeWatcherAdapter();
     }
     return NodeWatcherSingleton.instance;
   }
diff --git a/src/presentation/nodeWatcher/NodeWatcher.port.ts b/src/presentation/nodeWatcher/NodeWatcher.port.ts
new file mode 100644
index 0000000..83372b6
--- /dev/null
+++ b/src/presentation/nodeWatcher/NodeWatcher.port.ts
@@ -0,0 +1,23 @@
+import { NodeWatcherHandler } from "./NodeWatcherHandler";
+
+export interface NodeWatcherPort {
+  /**
+   * Start watching mutations to nodes.
+   */
+  start(): void;
+
+  /**
+   * Pause watching mutations to nodes.
+   */
+  pause(): void;
+
+  /**
+   * Add a handler to watch certain mutations.
+   */
+  setHandler(key: string, handler: NodeWatcherHandler): void;
+
+  /**
+   * Remove a handler by key.
+   */
+  removeHandler(key: string): boolean;
+}
diff --git a/src/common/nodeWatcher/NodeWatcherHandler.ts b/src/presentation/nodeWatcher/NodeWatcherHandler.ts
similarity index 100%
rename from src/common/nodeWatcher/NodeWatcherHandler.ts
rename to src/presentation/nodeWatcher/NodeWatcherHandler.ts