diff --git a/client/src/features/xero/use-xero-desktop-state/runtime-stream.ts b/client/src/features/xero/use-xero-desktop-state/runtime-stream.ts
index 47e09cae..d46dec42 100644
--- a/client/src/features/xero/use-xero-desktop-state/runtime-stream.ts
+++ b/client/src/features/xero/use-xero-desktop-state/runtime-stream.ts
@@ -638,6 +638,22 @@ export function createRuntimeStreamEventBuffer({
   let cancelScheduledFlush: ScheduledFlushCancel | null = null
   let disposed = false
   let completionNotificationsEnabled = false
+  let pendingTranscriptTextChunks: string[] | null = null
+
+  const flushPendingTranscriptText = () => {
+    if (!pendingTranscriptTextChunks) {
+      return
+    }
+
+    const previous = pendingEvents.at(-1)
+    if (previous && !isRuntimeStreamPatch(previous) && previous.item.kind === 'transcript') {
+      previous.item = {
+        ...previous.item,
+        text: pendingTranscriptTextChunks.join(''),
+      }
+    }
+    pendingTranscriptTextChunks = null
+  }
 
   const cancelFlush = () => {
     if (!cancelScheduledFlush) {
@@ -659,6 +675,7 @@ export function createRuntimeStreamEventBuffer({
       return
     }
 
+    flushPendingTranscriptText()
     const events = pendingEvents.splice(0, pendingEvents.length)
     updateRuntimeStream(projectId, agentSessionId, (currentStream) => mergeRuntimeStreamEvents(currentStream, events))
     if (completionNotificationsEnabled) {
@@ -718,8 +735,33 @@ export function createRuntimeStreamEventBuffer({
 
       if (isRuntimeStreamPatch(payload)) {
         pendingEvents.length = 0
+        pendingTranscriptTextChunks = null
       }
-      pendingEvents.push(payload)
+
+      const previous = pendingEvents.at(-1)
+      if (
+        previous &&
+        !isRuntimeStreamPatch(previous) &&
+        !isRuntimeStreamPatch(payload) &&
+        canAggregateRuntimeTranscriptDelta(previous, payload)
+      ) {
+        pendingTranscriptTextChunks ??= [previous.item.text ?? '']
+        pendingTranscriptTextChunks.push(payload.item.text ?? '')
+        previous.item = {
+          ...previous.item,
+          updatedSequence: runtimeStreamPayloadUpdateSequence(payload),
+          createdAt: payload.item.createdAt,
+        }
+        schedule()
+        return
+      }
+
+      flushPendingTranscriptText()
+      pendingEvents.push(
+        !isRuntimeStreamPatch(payload) && payload.item.kind === 'transcript'
+          ? cloneRuntimeStreamEventForAggregation(payload)
+          : payload,
+      )
       if (isUrgentRuntimeStreamEvent(payload)) {
         flush()
         return
@@ -736,6 +778,7 @@ export function createRuntimeStreamEventBuffer({
       disposed = true
       cancelFlush()
       pendingEvents.length = 0
+      pendingTranscriptTextChunks = null
     },
   }
 }