Handle compaction event type

Author: Theodore Li

apps/sim/app/workspace/[workspaceId]/home/hooks/use-chat.ts

@@ -527,6 +527,7 @@ export function useChat(
       const toolArgsMap = new Map<string, Record<string, unknown>>()
       const clientExecutionStarted = new Set<string>()
       let activeSubagent: string | undefined
+      let activeCompactionId: string | undefined
       let runningText = ''
       let lastContentSource: 'main' | 'subagent' | null = null
       let streamRequestId: string | undefined
@@ -853,6 +854,44 @@ export function useChat(
               }
               break
             }
+            case 'context_compaction_start': {
+              const compactionId = `compaction_${Date.now()}`
+              activeCompactionId = compactionId
+              toolMap.set(compactionId, blocks.length)
+              blocks.push({
+                type: 'tool_call',
+                toolCall: {
+                  id: compactionId,
+                  name: 'context_compaction',
+                  status: 'executing',
+                  displayTitle: 'Compacting context...',
+                },
+              })
+              flush()
+              break
+            }
+            case 'context_compaction': {
+              const compactionId = activeCompactionId || `compaction_${Date.now()}`
+              activeCompactionId = undefined
+              const idx = toolMap.get(compactionId)
+              if (idx !== undefined && blocks[idx]?.toolCall) {
+                blocks[idx].toolCall!.status = 'success'
+                blocks[idx].toolCall!.displayTitle = 'Compacted context'
+              } else {
+                toolMap.set(compactionId, blocks.length)
+                blocks.push({
+                  type: 'tool_call',
+                  toolCall: {
+                    id: compactionId,
+                    name: 'context_compaction',
+                    status: 'success',
+                    displayTitle: 'Compacted context',
+                  },
+                })
+              }
+              flush()
+              break
+            }
             case 'tool_error': {
               const id = parsed.toolCallId || getPayloadData(parsed)?.id
               if (!id) break

apps/sim/app/workspace/[workspaceId]/home/types.ts

@@ -49,6 +49,8 @@ export type SSEEventType =
   | 'structured_result' // structured result from a tool call
   | 'subagent_result' // result from a subagent
   | 'done' // end of the chat
+  | 'context_compaction_start' // context compaction started
+  | 'context_compaction' // conversation context was compacted
   | 'error' // error in the chat
   | 'start' // start of the chat
 
@@ -94,6 +96,7 @@ export type MothershipToolName =
   | 'edit'
   | 'fast_edit'
   | 'open_resource'
+  | 'context_compaction'
 
 /**
  * Subagent identifiers dispatched via `subagent_start` SSE events.
@@ -349,6 +352,11 @@ export const TOOL_UI_METADATA: Partial<Record<MothershipToolName, ToolUIMetadata
     phaseLabel: 'Resource',
     phase: 'resource',
   },
+  context_compaction: {
+    title: 'Compacted context',
+    phaseLabel: 'Context',
+    phase: 'management',
+  },
 }
 
 export interface SSEPayloadUI {