From e458d6391db3932cce903248bb856fdf0fc5730b Mon Sep 17 00:00:00 2001
From: claude-code-best <claude-code-best@proton.me>
Date: Tue, 14 Apr 2026 09:56:22 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20compact=20=E6=A8=A1=E5=9E=8B=E9=99=8D?=
 =?UTF-8?q?=E7=BA=A7=E4=B8=BA=20-1=20=E6=A8=A1=E5=BC=8F=EF=BC=88Opus?=
 =?UTF-8?q?=E2=86=92Sonnet,=20Sonnet=E2=86=92Haiku=EF=BC=89?=
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Content-Type: text/plain; charset=UTF-8
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Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src/services/compact/compact.ts |  5 +++--
 src/utils/model/model.ts        | 22 ++++++++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/services/compact/compact.ts b/src/services/compact/compact.ts
index f46194ffb..a0d5903d1 100644
--- a/src/services/compact/compact.ts
+++ b/src/services/compact/compact.ts
@@ -103,6 +103,7 @@ import {
   getMaxOutputTokensForModel,
   queryModelWithStreaming,
 } from '../api/claude.js'
+import { getCompactModel } from '../../utils/model/model.js'
 import {
   getPromptTooLongTokenGap,
   PROMPT_TOO_LONG_ERROR_MESSAGE,
@@ -1314,13 +1315,13 @@ async function streamCompactSummary({
             const appState = context.getAppState()
             return appState.toolPermissionContext
           },
-          model: context.options.mainLoopModel,
+          model: getCompactModel(context.options.mainLoopModel),
           toolChoice: undefined,
           isNonInteractiveSession: context.options.isNonInteractiveSession,
           hasAppendSystemPrompt: !!context.options.appendSystemPrompt,
           maxOutputTokensOverride: Math.min(
             COMPACT_MAX_OUTPUT_TOKENS,
-            getMaxOutputTokensForModel(context.options.mainLoopModel),
+            getMaxOutputTokensForModel(getCompactModel(context.options.mainLoopModel)),
           ),
           querySource: 'compact',
           agents: context.options.agentDefinitions.activeAgents,
diff --git a/src/utils/model/model.ts b/src/utils/model/model.ts
index 791daeb6b..1aa3c79a6 100644
--- a/src/utils/model/model.ts
+++ b/src/utils/model/model.ts
@@ -47,6 +47,28 @@ export function getSmallFastModel(): ModelName {
   return process.env.ANTHROPIC_SMALL_FAST_MODEL || getDefaultHaikuModel()
 }
 
+/**
+ * Get the model to use for compaction, one tier below the current model.
+ * Opus → Sonnet, Sonnet → Haiku, Haiku → Haiku (already lowest).
+ * Preserves [1m] suffix only if the target family supports it (sonnet/opus).
+ */
+export function getCompactModel(model: ModelName): ModelName {
+  const has1m = model.endsWith('[1m]')
+  const baseModel = has1m ? model.slice(0, -4) : model
+  const canonical = getCanonicalName(baseModel)
+
+  // Opus family → Sonnet
+  if (canonical.includes('opus')) {
+    return getDefaultSonnetModel()
+  }
+  // Sonnet family → Haiku
+  if (canonical.includes('sonnet')) {
+    return getDefaultHaikuModel()
+  }
+  // Haiku or unknown → Haiku (lowest tier)
+  return getDefaultHaikuModel()
+}
+
 export function isNonCustomOpusModel(model: ModelName): boolean {
   return (
     model === getModelStrings().opus40 ||