diff --git a/src/hub/hub.ts b/src/hub/hub.ts
index 1676309b3e..8ba68d64a6 100644
--- a/src/hub/hub.ts
+++ b/src/hub/hub.ts
@@ -30,7 +30,6 @@ import { evaluateCommandSafety, requiresApproval } from "../agent/tools/exec-saf
 import { addAllowlistEntry, recordAllowlistUse, matchAllowlist } from "../agent/tools/exec-allowlist.js";
 import type { ExecApprovalCallback, ExecApprovalConfig, ApprovalResult, ExecApprovalRequest } from "../agent/tools/exec-approval-types.js";
 import { readProfileConfig, writeProfileConfig } from "../agent/profile/storage.js";
-import { MessageAggregator, type BlockChunkerConfig, DEFAULT_CHUNKER_CONFIG } from "./message-aggregator.js";
 
 export class Hub {
   private readonly agents = new Map<string, AsyncAgent>();
@@ -38,7 +37,6 @@ export class Hub {
   private readonly agentStreamIds = new Map<string, string>();
   private readonly agentStreamCounters = new Map<string, number>();
   private readonly localApprovalHandlers = new Map<string, (payload: ExecApprovalRequest) => void>();
-  private readonly agentAggregators = new Map<string, MessageAggregator>();
   private readonly rpc: RpcDispatcher;
   private readonly approvalManager: ExecApprovalManager;
   private client: GatewayClient;
@@ -245,60 +243,6 @@ export class Hub {
     return this.approvalManager.resolveApproval(approvalId, decision);
   }
 
-  /**
-   * Enable message aggregation for an agent.
-   * When enabled, streaming text deltas are buffered and emitted as complete block replies
-   * instead of being forwarded as raw events. Useful for third-party messaging integrations.
-   */
-  enableAggregation(agentId: string, config?: Partial<BlockChunkerConfig>): void {
-    const fullConfig = { ...DEFAULT_CHUNKER_CONFIG, ...config };
-    const aggregator = new MessageAggregator(
-      fullConfig,
-      (block) => {
-        const targetDeviceId = this.agentSenders.get(agentId);
-        if (!targetDeviceId) return;
-        this.client.send(targetDeviceId, "block-reply", {
-          agentId,
-          block,
-        });
-      },
-      (event) => {
-        const targetDeviceId = this.agentSenders.get(agentId);
-        if (!targetDeviceId) return;
-
-        const isCompactionEvent =
-          event.type === "compaction_start" || event.type === "compaction_end";
-        if (isCompactionEvent) {
-          this.client.send(targetDeviceId, StreamAction, {
-            streamId: `compaction:${agentId}`,
-            agentId,
-            event,
-          });
-          return;
-        }
-
-        if (event.type === "message_start") {
-          this.beginStream(agentId, event);
-        }
-        const streamId = this.getActiveStreamId(agentId, event);
-        this.client.send(targetDeviceId, StreamAction, {
-          streamId,
-          agentId,
-          event,
-        });
-        if (event.type === "message_end") {
-          this.endStream(agentId);
-        }
-      },
-    );
-    this.agentAggregators.set(agentId, aggregator);
-  }
-
-  /** Disable message aggregation for an agent (reverts to streaming mode). */
-  disableAggregation(agentId: string): void {
-    this.agentAggregators.delete(agentId);
-  }
-
   /** Create new Agent, or rebuild with existing ID */
   createAgent(id?: string, options?: { persist?: boolean; profileId?: string }): AsyncAgent {
     if (id) {
@@ -368,13 +312,20 @@ export class Hub {
           agentId: agent.sessionId,
           content: item.content,
         });
-        continue;
-      }
+      } else {
+        // Compaction events: forward with synthetic streamId (no stream tracking)
+        const isCompactionEvent =
+          item.type === "compaction_start" || item.type === "compaction_end";
+        if (isCompactionEvent) {
+          this.client.send(targetDeviceId, StreamAction, {
+            streamId: `compaction:${agent.sessionId}`,
+            agentId: agent.sessionId,
+            event: item,
+          });
+          continue;
+        }
 
-      // Filter: only forward events useful for frontend rendering
-      const isCompactionEvent =
-        item.type === "compaction_start" || item.type === "compaction_end";
-      if (!isCompactionEvent) {
+        // Filter: only forward events useful for frontend rendering
         const maybeMessage = (item as { message?: { role?: string } }).message;
         const isAssistantMessage = maybeMessage?.role === "assistant";
         const shouldForward =
@@ -382,36 +333,19 @@ export class Hub {
           || item.type === "tool_execution_start"
           || item.type === "tool_execution_end";
         if (!shouldForward) continue;
-      }
 
-      // Aggregated mode: buffer text deltas, emit block replies
-      const aggregator = this.agentAggregators.get(agent.sessionId);
-      if (aggregator) {
-        aggregator.handleEvent(item);
-        continue;
-      }
-
-      // Streaming mode: forward events as-is (existing behavior)
-      if (isCompactionEvent) {
+        if (item.type === "message_start") {
+          this.beginStream(agent.sessionId, item);
+        }
+        const streamId = this.getActiveStreamId(agent.sessionId, item);
         this.client.send(targetDeviceId, StreamAction, {
-          streamId: `compaction:${agent.sessionId}`,
+          streamId,
           agentId: agent.sessionId,
           event: item,
         });
-        continue;
-      }
-
-      if (item.type === "message_start") {
-        this.beginStream(agent.sessionId, item);
-      }
-      const streamId = this.getActiveStreamId(agent.sessionId, item);
-      this.client.send(targetDeviceId, StreamAction, {
-        streamId,
-        agentId: agent.sessionId,
-        event: item,
-      });
-      if (item.type === "message_end") {
-        this.endStream(agent.sessionId);
+        if (item.type === "message_end") {
+          this.endStream(agent.sessionId);
+        }
       }
     }
   }
@@ -569,7 +503,6 @@ export class Hub {
     this.agentStreamIds.delete(id);
     this.agentStreamCounters.delete(id);
     this.localApprovalHandlers.delete(id);
-    this.agentAggregators.delete(id);
     removeAgentRecord(id);
     return true;
   }
@@ -585,7 +518,6 @@ export class Hub {
       this.agentStreamIds.delete(id);
       this.agentStreamCounters.delete(id);
       this.localApprovalHandlers.delete(id);
-      this.agentAggregators.delete(id);
     }
     this.client.disconnect();
     console.log("Hub shut down");