From 87c5e5439144ddcd03dc0f5f2bafc2e087e6db46 Mon Sep 17 00:00:00 2001
From: 7Sageer <7sageer@djwcb.cn>
Date: Wed, 17 Jun 2026 19:32:44 +0800
Subject: [PATCH 1/3] feat(agent-core): record context length before and after
 micro compaction

---
 .../record-micro-compaction-context-length.md       |  6 ++++++
 packages/agent-core/src/agent/compaction/micro.ts   | 13 ++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/record-micro-compaction-context-length.md

diff --git a/.changeset/record-micro-compaction-context-length.md b/.changeset/record-micro-compaction-context-length.md
new file mode 100644
index 000000000..412a15272
--- /dev/null
+++ b/.changeset/record-micro-compaction-context-length.md
@@ -0,0 +1,6 @@
+---
+"@moonshot-ai/agent-core": patch
+"@moonshot-ai/kimi-code": patch
+---
+
+Record context token length before and after micro compaction.
diff --git a/packages/agent-core/src/agent/compaction/micro.ts b/packages/agent-core/src/agent/compaction/micro.ts
index da352db69..e08e5e9ce 100644
--- a/packages/agent-core/src/agent/compaction/micro.ts
+++ b/packages/agent-core/src/agent/compaction/micro.ts
@@ -2,7 +2,10 @@ import type { ContentPart } from '@moonshot-ai/kosong';
 
 import type { Agent } from '..';
 import type { ContextMessage } from '../context';
-import { estimateTokensForContentParts } from '../../utils/tokens';
+import {
+  estimateTokensForContentParts,
+  estimateTokensForMessages,
+} from '../../utils/tokens';
 
 export interface MicroCompactionConfig {
   keepRecentMessages: number;
@@ -65,9 +68,17 @@ export class MicroCompaction {
     this.apply(nextCutoff);
     if (previousCutoff !== nextCutoff) {
       const effect = this.measureEffect(history, nextCutoff);
+      // Whole-context length before/after trimming, mirroring the
+      // `tokensBefore`/`tokensAfter` fields on `compaction_finished` so the
+      // two compaction paths can be compared on the same axis.
+      const contextTokensBefore = estimateTokensForMessages(history);
+      const contextTokensAfter =
+        contextTokensBefore - effect.beforeTokens + effect.afterTokens;
       this.agent.telemetry.track('micro_compaction_applied', {
         ...config,
         ...effect,
+        contextTokensBefore,
+        contextTokensAfter,
         previous_cutoff: previousCutoff,
         cutoff: nextCutoff,
         message_count: history.length,

From 9bf5c530d6546d6782b8a006846c881a1811a309 Mon Sep 17 00:00:00 2001
From: 7Sageer <7sageer@djwcb.cn>
Date: Wed, 17 Jun 2026 19:33:49 +0800
Subject: [PATCH 2/3] test(agent-core): assert context length fields in micro
 compaction telemetry

---
 packages/agent-core/test/agent/compaction/micro.test.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages/agent-core/test/agent/compaction/micro.test.ts b/packages/agent-core/test/agent/compaction/micro.test.ts
index bcdeb327e..033333188 100644
--- a/packages/agent-core/test/agent/compaction/micro.test.ts
+++ b/packages/agent-core/test/agent/compaction/micro.test.ts
@@ -480,10 +480,15 @@ describe('MicroCompaction', () => {
       truncatedToolResultCount: 2,
       beforeTokens: expect.any(Number),
       afterTokens: expect.any(Number),
+      contextTokensBefore: expect.any(Number),
+      contextTokensAfter: expect.any(Number),
     });
     expect(numberProperty(event, 'beforeTokens')).toBeGreaterThan(
       numberProperty(event, 'afterTokens'),
     );
+    expect(numberProperty(event, 'contextTokensBefore')).toBeGreaterThan(
+      numberProperty(event, 'contextTokensAfter'),
+    );
 
     expect(ctx.agent.context.messages).toHaveLength(9);
     expect(records.filter((record) => record.event === 'micro_compaction_applied')).toHaveLength(1);

From 608a811648e9c59a001ae11b12294d7b1b0687b6 Mon Sep 17 00:00:00 2001
From: 7Sageer <7sageer@djwcb.cn>
Date: Wed, 17 Jun 2026 20:12:57 +0800
Subject: [PATCH 3/3] chore: drop changeset for telemetry-only change

---
 .changeset/record-micro-compaction-context-length.md | 6 ------
 1 file changed, 6 deletions(-)
 delete mode 100644 .changeset/record-micro-compaction-context-length.md

diff --git a/.changeset/record-micro-compaction-context-length.md b/.changeset/record-micro-compaction-context-length.md
deleted file mode 100644
index 412a15272..000000000
--- a/.changeset/record-micro-compaction-context-length.md
+++ /dev/null
@@ -1,6 +0,0 @@
----
-"@moonshot-ai/agent-core": patch
-"@moonshot-ai/kimi-code": patch
----
-
-Record context token length before and after micro compaction.