diff --git a/apps/flipcash/shared/chat/src/main/kotlin/com/flipcash/shared/chat/reactions/ReactionRefreshPlanner.kt b/apps/flipcash/shared/chat/src/main/kotlin/com/flipcash/shared/chat/reactions/ReactionRefreshPlanner.kt
index 469c4ea743..60438baf4a 100644
--- a/apps/flipcash/shared/chat/src/main/kotlin/com/flipcash/shared/chat/reactions/ReactionRefreshPlanner.kt
+++ b/apps/flipcash/shared/chat/src/main/kotlin/com/flipcash/shared/chat/reactions/ReactionRefreshPlanner.kt
@@ -13,6 +13,10 @@ package com.flipcash.shared.chat.reactions
  *    reaction state, so refreshing it again would be redundant.
  *
  * Both are pure: callers own the "already refreshed" bookkeeping and pass in what's still needed.
+ *
+ * Both drop ids below 1. A pending or failed send is stored as `-(now)`, has no reactions to fetch,
+ * and fails the `MessageId` rule (>= 1) for the whole batch it rides in. Its real id arrives with
+ * the server echo and pages in as a new id.
  */
 object ReactionRefreshPlanner {
 
@@ -30,6 +34,7 @@ object ReactionRefreshPlanner {
     ): List<Long> =
         newestFirstIds
             .asSequence()
+            .filter { it >= 1 }
             .take(windowSize)
             .filterNot { it in alreadyRefreshed }
             .toList()
@@ -47,7 +52,7 @@ object ReactionRefreshPlanner {
         chunkSize: Int = DEFAULT_CHUNK_SIZE,
     ): List<List<Long>> {
         if (sourcedFromServer) return emptyList()
-        val remaining = pageIds.filterNot { it in alreadyRefreshed }
+        val remaining = pageIds.filter { it >= 1 && it !in alreadyRefreshed }
         if (remaining.isEmpty()) return emptyList()
         return remaining.chunked(chunkSize)
     }
diff --git a/apps/flipcash/shared/chat/src/test/kotlin/com/flipcash/shared/chat/reactions/ReactionRefreshPlannerTest.kt b/apps/flipcash/shared/chat/src/test/kotlin/com/flipcash/shared/chat/reactions/ReactionRefreshPlannerTest.kt
index afecbb764f..be5b178b34 100644
--- a/apps/flipcash/shared/chat/src/test/kotlin/com/flipcash/shared/chat/reactions/ReactionRefreshPlannerTest.kt
+++ b/apps/flipcash/shared/chat/src/test/kotlin/com/flipcash/shared/chat/reactions/ReactionRefreshPlannerTest.kt
@@ -60,4 +60,20 @@ class ReactionRefreshPlannerTest {
         val chunks = ReactionRefreshPlanner.forLoadedPage(emptyList(), sourcedFromServer = false)
         assertEquals(emptyList<List<Long>>(), chunks)
     }
+
+    // A pending or failed send is stored as -(now) and sorts among the newest rows. The
+    // MessageId rule is >= 1, so one in a batch fails the whole request.
+
+    @Test
+    fun `initial window skips unsent ids and still fills the window`() {
+        val unsent = -1_700_000_000_000L
+        val window = ReactionRefreshPlanner.initialWindow(listOf(unsent, 5L, 4L, 3L), windowSize = 2)
+        assertEquals(listOf(5L, 4L), window)
+    }
+
+    @Test
+    fun `loaded page of only an unsent id yields no chunks`() {
+        val chunks = ReactionRefreshPlanner.forLoadedPage(listOf(-1_700_000_000_000L), sourcedFromServer = false)
+        assertEquals(emptyList<List<Long>>(), chunks)
+    }
 }