diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc74fc7e9b8..2f3319ff152 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ Docs: https://docs.openclaw.ai
 - Workspace/oc-path: add the `oc://` addressing substrate (`src/oc-path/`) — a universal, kind-dispatched path scheme for addressing leaves and nodes inside markdown, jsonc, jsonl, and yaml workspace files, with `parseOcPath`/`formatOcPath`, per-kind `parseXxx`/`emitXxx`, universal `resolveOcPath`/`setOcPath`/`findOcPaths` verbs, the `__OPENCLAW_REDACTED__` sentinel emit guard, and the new `openclaw path resolve|find|set|validate|emit` CLI for shell-level inspection and surgical edits. Implements #78051. (#78678) Thanks @giodl73-repo.
 - Runtime/performance: avoid full-array sorting while auto-selecting providers, resolving supported thinking levels, picking node last-seen timestamps, and extracting Codex usage-limit messages. Thanks @shakkernerd.
 - Plugins/doctor: avoid full-array sorting while selecting ClawHub search/archive results and bounded dreaming doctor entries. Thanks @shakkernerd.
+- Agents/compaction: keep contributor diagnostics to a bounded top-three selection without sorting the full history. Thanks @shakkernerd.
 - Telegram: preserve the channel-specific 10-option poll cap in the unified outbound adapter so over-limit polls are rejected before send. (#78762) Thanks @obviyus.
 - Slack: route handled top-level channel turns in implicit-conversation channels to thread-scoped sessions when Slack reply threading is enabled, keeping the root turn and later thread replies on one OpenClaw session. (#78522) Thanks @zeroth-blip.
 - Telegram: re-probe the primary fetch transport after repeated sticky fallback success so transient IPv4 or pinned-IP fallback promotion can recover without a gateway restart. Fixes #77088. (#77157) Thanks @MkDev11.
diff --git a/src/agents/pi-embedded-runner/compact.ts b/src/agents/pi-embedded-runner/compact.ts
index 1ebc6e00af6..79810272482 100644
--- a/src/agents/pi-embedded-runner/compact.ts
+++ b/src/agents/pi-embedded-runner/compact.ts
@@ -323,10 +323,34 @@ function summarizeCompactionMessages(messages: AgentMessage[]): CompactionMessag
     historyTextChars,
     toolResultChars,
     estTokens: tokenEstimationFailed ? undefined : estTokens,
-    contributors: contributors.toSorted((a, b) => b.chars - a.chars).slice(0, 3),
+    contributors: selectTopContributors(contributors),
   };
 }
 
+function selectTopContributors(
+  contributors: CompactionMessageMetrics["contributors"],
+): CompactionMessageMetrics["contributors"] {
+  const selected: CompactionMessageMetrics["contributors"] = [];
+  for (const contributor of contributors) {
+    let insertAt = selected.length;
+    for (let index = 0; index < selected.length; index += 1) {
+      if (contributor.chars > selected[index].chars) {
+        insertAt = index;
+        break;
+      }
+    }
+    if (insertAt < 3) {
+      selected.splice(insertAt, 0, contributor);
+      if (selected.length > 3) {
+        selected.pop();
+      }
+    } else if (selected.length < 3) {
+      selected.push(contributor);
+    }
+  }
+  return selected;
+}
+
 function containsRealConversationMessages(messages: AgentMessage[]): boolean {
   return messages.some((message, index, allMessages) =>
     hasRealConversationContent(message, allMessages, index),