diff --git a/release-notes/v0.5.5.md b/release-notes/v0.5.5.md
index 2933cd9d..e3a5a571 100644
--- a/release-notes/v0.5.5.md
+++ b/release-notes/v0.5.5.md
@@ -19,6 +19,13 @@
 - **Read 工具空 `pages` 容错**。`pages: ""` 视为读全文件，避免模型传空字符串触发的反复校验报错。
 - **Fork 化指向**。仓库链接、检查更新源（electron-updater publish + Tauri 端点）改为指向本 fork
   `706412584/cc-haha`；设置→关于 新增"Fork 维护者"署名（706412584），原作者 NanmiCoder 署名与社交链接保留。
+- **修复上下文压缩抖动/死循环**。此前自动压缩只对"压缩失败"做熔断，"压缩成功但结果仍超阈值"会被
+  当成成功并清零失败计数，导致每隔几句话就再压一次、空烧摘要 API。现在：(方案1) 压缩后若仍超阈值
+  记为"无效压缩"并计入熔断，连续若干次后停止自动压缩；(方案2) 一次压缩后的若干轮内不再主动压缩
+  （触及硬阻塞上限时除外，避免 prompt-too-long）。
+- **修复压缩后上下文进度卡 100%**。设置/编辑框的上下文进度在压缩完成后会停在 ~100% 不回落，直到
+  下一轮对话。根因是 transcript 估算路径未切到压缩边界之后（把压缩前全部消息 + 摘要调用的巨大
+  input 都算进去）。现在估算只统计最近一次压缩边界之后的消息，压缩完成即正确回落。
 
 ## 范围
 
diff --git a/src/query.ts b/src/query.ts
index ef1251f2..e98585d4 100644
--- a/src/query.ts
+++ b/src/query.ts
@@ -520,11 +520,14 @@ async function* queryLoop(
       // compact. recompactionInfo (autoCompact.ts:190) already captured the
       // old values for turnsSincePreviousCompact/previousCompactTurnId before
       // the call, so this reset doesn't lose those.
+      // consecutiveFailures is normally 0 here, but an "ineffective" compaction
+      // (post-compact context still over threshold) returns a non-zero count so
+      // the circuit breaker can stop a re-compaction loop.
       tracking = {
         compacted: true,
         turnId: deps.uuid(),
         turnCounter: 0,
-        consecutiveFailures: 0,
+        consecutiveFailures: consecutiveFailures ?? 0,
       }
 
       const postCompactMessages = buildPostCompactMessages(compactionResult)
diff --git a/src/server/__tests__/conversations.test.ts b/src/server/__tests__/conversations.test.ts
index e0b82bed..7b86a9ef 100644
--- a/src/server/__tests__/conversations.test.ts
+++ b/src/server/__tests__/conversations.test.ts
@@ -12,6 +12,7 @@ import * as os from 'os'
 import { execFileSync } from 'node:child_process'
 import { fileURLToPath } from 'node:url'
 import { ConversationService, ConversationStartupError, conversationService } from '../services/conversationService.js'
+import { ORCHESTRATION_PROMPT_MARKER } from '../orchestrationPrompt.js'
 import { SessionService, sessionService } from '../services/sessionService.js'
 import { ProviderService } from '../services/providerService.js'
 
@@ -242,6 +243,20 @@ describe('ConversationService', () => {
     ])
   })
 
+  it('should append the orchestration system prompt when coordinator mode is on', () => {
+    const svc = new ConversationService()
+    const args = (svc as any).getRuntimeArgs({ coordinatorMode: true }) as string[]
+    const idx = args.indexOf('--append-system-prompt')
+    expect(idx).toBeGreaterThanOrEqual(0)
+    expect(args[idx + 1]).toContain(ORCHESTRATION_PROMPT_MARKER)
+  })
+
+  it('should not append the orchestration system prompt when coordinator mode is off', () => {
+    const svc = new ConversationService()
+    expect((svc as any).getRuntimeArgs({ coordinatorMode: false })).not.toContain('--append-system-prompt')
+    expect((svc as any).getRuntimeArgs({})).not.toContain('--append-system-prompt')
+  })
+
   it('should send thinking token controls to active CLI sessions', () => {
     const svc = new ConversationService() as any
     const sent: string[] = []
@@ -684,11 +699,87 @@ describe('ConversationService', () => {
       await fs.rm(workDir, { recursive: true, force: true })
     }
   })
-})
 
-// ============================================================================
-// WebSocket integration tests (with mock CLI using the SDK websocket protocol)
-// ============================================================================
+  it('scopes the transcript context estimate to messages after the latest compact boundary', async () => {
+    const previousConfigDir = process.env.CLAUDE_CONFIG_DIR
+    const previousNodeEnv = process.env.NODE_ENV
+    const previousUseBedrock = process.env.CLAUDE_CODE_USE_BEDROCK
+    const tmpConfigDir = await fs.mkdtemp(path.join(os.tmpdir(), 'claude-transcript-compact-'))
+    const workDir = await fs.mkdtemp(path.join(os.tmpdir(), 'claude-workdir-compact-'))
+    process.env.CLAUDE_CONFIG_DIR = tmpConfigDir
+    process.env.NODE_ENV = 'development'
+    process.env.CLAUDE_CODE_USE_BEDROCK = '1'
+
+    try {
+      const svc = new SessionService()
+      const { sessionId } = await svc.createSession(workDir)
+      const found = await svc.findSessionFile(sessionId)
+      expect(found).not.toBeNull()
+
+      // Pre-compact turn: a near-full request (would read as ~100%).
+      await fs.appendFile(found!.filePath, JSON.stringify({
+        type: 'assistant',
+        uuid: crypto.randomUUID(),
+        timestamp: '2026-04-27T12:00:00.000Z',
+        cwd: workDir,
+        version: '999.0.0-test',
+        message: {
+          role: 'assistant',
+          model: 'claude-sonnet-4-6',
+          content: [{ type: 'text', text: 'pre-compact answer' }],
+          usage: { input_tokens: 190_000, output_tokens: 50 },
+        },
+      }) + '\n')
+
+      // Compaction boundary — everything above is no longer in live context.
+      await fs.appendFile(found!.filePath, JSON.stringify({
+        type: 'system',
+        subtype: 'compact_boundary',
+        uuid: crypto.randomUUID(),
+        timestamp: '2026-04-27T12:00:01.000Z',
+        cwd: workDir,
+      }) + '\n')
+
+      // Post-compact: just the small summary, no new real turn yet.
+      await fs.appendFile(found!.filePath, JSON.stringify({
+        type: 'user',
+        uuid: crypto.randomUUID(),
+        timestamp: '2026-04-27T12:00:02.000Z',
+        cwd: workDir,
+        message: {
+          role: 'user',
+          content: [{ type: 'text', text: 'Summary of the prior conversation: we did a few things.' }],
+        },
+      }) + '\n')
+
+      const contextEstimate = await svc.getTranscriptContextEstimate(sessionId)
+
+      expect(contextEstimate?.rawMaxTokens).toBe(200_000)
+      // The pre-compact 190k request must NOT anchor the estimate post-compaction.
+      expect(contextEstimate?.percentage).toBeLessThan(50)
+      expect(contextEstimate?.totalTokens).toBeLessThan(50_000)
+      expect(contextEstimate?.model).toBe('claude-sonnet-4-6')
+    } finally {
+      if (previousConfigDir === undefined) {
+        delete process.env.CLAUDE_CONFIG_DIR
+      } else {
+        process.env.CLAUDE_CONFIG_DIR = previousConfigDir
+      }
+      if (previousNodeEnv === undefined) {
+        delete process.env.NODE_ENV
+      } else {
+        process.env.NODE_ENV = previousNodeEnv
+      }
+      if (previousUseBedrock === undefined) {
+        delete process.env.CLAUDE_CODE_USE_BEDROCK
+      } else {
+        process.env.CLAUDE_CODE_USE_BEDROCK = previousUseBedrock
+      }
+      await fs.rm(tmpConfigDir, { recursive: true, force: true })
+      await fs.rm(workDir, { recursive: true, force: true })
+    }
+  })
+})
 
 describe('WebSocket Chat Integration', () => {
   let server: ReturnType<typeof Bun.serve>
diff --git a/src/server/services/sessionService.ts b/src/server/services/sessionService.ts
index 8d1ace45..4d0031aa 100644
--- a/src/server/services/sessionService.ts
+++ b/src/server/services/sessionService.ts
@@ -1382,6 +1382,24 @@ export class SessionService {
     if (!found) return null
 
     const entries = await this.readJsonlFile(found.filePath)
+
+    // After a compaction the transcript still holds the full pre-compact
+    // history, but the live context only contains messages after the latest
+    // compact boundary. Scope the estimate to post-boundary entries so the
+    // indicator doesn't report a stale ~100% — both the whole-transcript token
+    // estimate AND the summarization call's huge input_tokens would otherwise
+    // keep it pinned near full until the next real turn lands.
+    let boundaryIndex = -1
+    for (let i = entries.length - 1; i >= 0; i--) {
+      const entry = entries[i]!
+      if (entry.type === 'system' && entry.subtype === 'compact_boundary') {
+        boundaryIndex = i
+        break
+      }
+    }
+    const scopedEntries =
+      boundaryIndex >= 0 ? entries.slice(boundaryIndex + 1) : entries
+
     let latest: {
       model: string
       inputTokens: number
@@ -1390,7 +1408,7 @@ export class SessionService {
       cacheCreationInputTokens: number
     } | null = null
 
-    for (const entry of entries) {
+    for (const entry of scopedEntries) {
       const usage = entry.message?.usage
       const model = entry.message?.model
       if (!usage || typeof model !== 'string') continue
@@ -1411,11 +1429,31 @@ export class SessionService {
       }
     }
 
-    if (!latest) return null
+    // Resolve the model even when the post-compact segment has no usage yet
+    // (compaction just happened, no real turn since): we still want a valid
+    // post-compact estimate rather than null.
+    let model = latest?.model
+    if (!model) {
+      for (let i = entries.length - 1; i >= 0; i--) {
+        const candidate = entries[i]?.message?.model
+        if (typeof candidate === 'string') {
+          model = candidate
+          break
+        }
+      }
+    }
+    if (!model) return null
 
-    const rawMaxTokens = await this.getTranscriptContextWindow(sessionId, latest.model)
-    const promptTokens = latest.inputTokens + latest.cacheReadInputTokens + latest.cacheCreationInputTokens
-    const transcriptMessages = entries.filter(entry =>
+    const usage = latest ?? {
+      inputTokens: 0,
+      outputTokens: 0,
+      cacheReadInputTokens: 0,
+      cacheCreationInputTokens: 0,
+    }
+
+    const rawMaxTokens = await this.getTranscriptContextWindow(sessionId, model)
+    const promptTokens = usage.inputTokens + usage.cacheReadInputTokens + usage.cacheCreationInputTokens
+    const transcriptMessages = scopedEntries.filter(entry =>
       entry.type === 'user' || entry.type === 'assistant' || entry.type === 'attachment',
     ) as Parameters<typeof roughTokenCountEstimationForMessages>[0]
     const estimatedTokens =
@@ -1423,12 +1461,16 @@ export class SessionService {
     const contextBudget = calculateContextBudget({
       estimatedTokens,
       contextWindow: rawMaxTokens,
-      currentUsage: {
-        input_tokens: latest.inputTokens,
-        output_tokens: latest.outputTokens,
-        cache_read_input_tokens: latest.cacheReadInputTokens,
-        cache_creation_input_tokens: latest.cacheCreationInputTokens,
-      },
+      // Without a post-compact API turn yet, there's no trustworthy provider
+      // usage to anchor to — fall back to the pure message-token estimate.
+      currentUsage: latest
+        ? {
+            input_tokens: latest.inputTokens,
+            output_tokens: latest.outputTokens,
+            cache_read_input_tokens: latest.cacheReadInputTokens,
+            cache_creation_input_tokens: latest.cacheCreationInputTokens,
+          }
+        : undefined,
       usageTrust: getProviderUsageTrust({
         isFirstPartyAnthropic: isFirstPartyAnthropicBaseUrl(),
       }),
@@ -1437,10 +1479,10 @@ export class SessionService {
     const totalTokens = contextBudget.usedTokens
     const percentage = rawMaxTokens > 0 ? Math.round((totalTokens / rawMaxTokens) * 100) : 0
     const usageCategories: TranscriptContextEstimate['categories'] = [
-      { name: 'Input tokens', tokens: latest.inputTokens, color: '#8f3217' },
-      { name: 'Cache read', tokens: latest.cacheReadInputTokens, color: '#0f5c8f' },
-      { name: 'Cache write', tokens: latest.cacheCreationInputTokens, color: '#7c3aed' },
-      { name: 'Output tokens', tokens: latest.outputTokens, color: '#2f7d32' },
+      { name: 'Input tokens', tokens: usage.inputTokens, color: '#8f3217' },
+      { name: 'Cache read', tokens: usage.cacheReadInputTokens, color: '#0f5c8f' },
+      { name: 'Cache write', tokens: usage.cacheCreationInputTokens, color: '#7c3aed' },
+      { name: 'Output tokens', tokens: usage.outputTokens, color: '#2f7d32' },
     ]
     const contextCategories: TranscriptContextEstimate['categories'] =
       contextBudget.ignoredUsageReason === 'low_trust_media_usage'
@@ -1474,15 +1516,15 @@ export class SessionService {
       rawMaxTokens,
       percentage,
       gridRows,
-      model: latest.model,
+      model,
       memoryFiles: [],
       mcpTools: [],
       agents: [],
       apiUsage: {
-        input_tokens: latest.inputTokens,
-        output_tokens: latest.outputTokens,
-        cache_creation_input_tokens: latest.cacheCreationInputTokens,
-        cache_read_input_tokens: latest.cacheReadInputTokens,
+        input_tokens: usage.inputTokens,
+        output_tokens: usage.outputTokens,
+        cache_creation_input_tokens: usage.cacheCreationInputTokens,
+        cache_read_input_tokens: usage.cacheReadInputTokens,
       },
     }
   }
diff --git a/src/services/compact/autoCompact.test.ts b/src/services/compact/autoCompact.test.ts
index 98e49ae5..e2a16ed5 100644
--- a/src/services/compact/autoCompact.test.ts
+++ b/src/services/compact/autoCompact.test.ts
@@ -1,6 +1,13 @@
 import { describe, expect, test, beforeEach, afterEach } from 'bun:test'
 
-import { getAutoCompactThreshold, getEffectiveContextWindowSize } from './autoCompact.js'
+import {
+  getAutoCompactThreshold,
+  getEffectiveContextWindowSize,
+  isIneffectiveCompaction,
+  shouldThrottleAutoCompact,
+  type AutoCompactTrackingState,
+} from './autoCompact.js'
+import type { CompactionResult } from './compact.js'
 import { getContextWindowForModel } from '../../utils/context.js'
 import { MODEL_CONTEXT_WINDOWS_ENV_KEY } from '../../utils/model/modelContextWindows.js'
 
@@ -67,3 +74,65 @@ describe('model context window resolution', () => {
     expect(getAutoCompactThreshold('MiniMax-M2.7')).toBe(171_800)
   })
 })
+
+function makeTracking(
+  overrides: Partial<AutoCompactTrackingState> = {},
+): AutoCompactTrackingState {
+  return {
+    compacted: true,
+    turnId: 'turn-1',
+    turnCounter: 0,
+    ...overrides,
+  }
+}
+
+function makeCompactionResult(
+  truePostCompactTokenCount: number | undefined,
+): CompactionResult {
+  // Only the field the predicate reads matters for these tests.
+  return { truePostCompactTokenCount } as unknown as CompactionResult
+}
+
+describe('方案2: shouldThrottleAutoCompact (turn throttle)', () => {
+  test('throttles for the first few turns after a compaction', () => {
+    expect(shouldThrottleAutoCompact(makeTracking({ turnCounter: 0 }), false)).toBe(true)
+    expect(shouldThrottleAutoCompact(makeTracking({ turnCounter: 1 }), false)).toBe(true)
+    expect(shouldThrottleAutoCompact(makeTracking({ turnCounter: 2 }), false)).toBe(true)
+  })
+
+  test('stops throttling once enough turns have elapsed', () => {
+    expect(shouldThrottleAutoCompact(makeTracking({ turnCounter: 3 }), false)).toBe(false)
+    expect(shouldThrottleAutoCompact(makeTracking({ turnCounter: 9 }), false)).toBe(false)
+  })
+
+  test('never throttles at the hard blocking limit, even right after a compaction', () => {
+    expect(shouldThrottleAutoCompact(makeTracking({ turnCounter: 0 }), true)).toBe(false)
+  })
+
+  test('does not throttle when no compaction has happened yet', () => {
+    expect(shouldThrottleAutoCompact(undefined, false)).toBe(false)
+    expect(
+      shouldThrottleAutoCompact(makeTracking({ compacted: false, turnCounter: 0 }), false),
+    ).toBe(false)
+  })
+})
+
+describe('方案1: isIneffectiveCompaction (recompaction-loop guard)', () => {
+  // deepseek-v4-pro: autocompact threshold is 967_000 (see math tests above).
+  const model = 'deepseek-v4-pro'
+  const threshold = getAutoCompactThreshold(model)
+
+  test('flags a compaction whose result is still at/above the threshold', () => {
+    expect(isIneffectiveCompaction(makeCompactionResult(threshold), model)).toBe(true)
+    expect(isIneffectiveCompaction(makeCompactionResult(threshold + 50_000), model)).toBe(true)
+  })
+
+  test('treats a compaction that got under the threshold as effective', () => {
+    expect(isIneffectiveCompaction(makeCompactionResult(threshold - 1), model)).toBe(false)
+    expect(isIneffectiveCompaction(makeCompactionResult(10_000), model)).toBe(false)
+  })
+
+  test('treats an unknown post-compact size as effective (no false circuit-break)', () => {
+    expect(isIneffectiveCompaction(makeCompactionResult(undefined), model)).toBe(false)
+  })
+})
diff --git a/src/services/compact/autoCompact.ts b/src/services/compact/autoCompact.ts
index 8c0a786d..01319a73 100644
--- a/src/services/compact/autoCompact.ts
+++ b/src/services/compact/autoCompact.ts
@@ -69,6 +69,13 @@ export const MANUAL_COMPACT_BUFFER_TOKENS = 3_000
 // in a single session, wasting ~250K API calls/day globally.
 const MAX_CONSECUTIVE_AUTOCOMPACT_FAILURES = 3
 
+// 方案2: minimum turns between two automatic compactions. After a successful
+// autocompaction we reset turnCounter to 0 (query.ts); we then refuse to
+// proactively compact again until this many turns have elapsed — UNLESS the
+// context is at the hard blocking limit (where skipping would risk a
+// prompt-too-long error). Prevents "compact every couple of messages" thrash.
+const MIN_TURNS_BETWEEN_AUTO_COMPACT = 3
+
 export function getAutoCompactThreshold(model: string): number {
   const effectiveContextWindow = getEffectiveContextWindowSize(model)
 
@@ -238,6 +245,37 @@ export async function shouldAutoCompact(
   return isAboveAutoCompactThreshold
 }
 
+// 方案2 predicate (pure, exported for tests): suppress proactive autocompaction
+// for the first MIN_TURNS_BETWEEN_AUTO_COMPACT turns after a compaction, but
+// never when we're already at the hard blocking limit.
+export function shouldThrottleAutoCompact(
+  tracking: AutoCompactTrackingState | undefined,
+  isAtBlockingLimit: boolean,
+): boolean {
+  if (isAtBlockingLimit) return false
+  return (
+    tracking?.compacted === true &&
+    tracking.turnCounter < MIN_TURNS_BETWEEN_AUTO_COMPACT
+  )
+}
+
+// 方案1: a compaction is "ineffective" when, after it completes, the resulting
+// context is still at or above the autocompact threshold — i.e. the very next
+// turn would trigger autocompact again. We feed these into the same circuit
+// breaker as hard failures so a run of ineffective compactions eventually
+// stops the loop instead of re-summarizing on every turn forever (each attempt
+// burns a full summarization API call). truePostCompactTokenCount is an
+// estimate; when it's absent we conservatively treat the compaction as
+// effective so we never falsely trip the breaker.
+export function isIneffectiveCompaction(
+  compactionResult: CompactionResult,
+  model: string,
+): boolean {
+  const truePost = compactionResult.truePostCompactTokenCount
+  if (truePost === undefined) return false
+  return truePost >= getAutoCompactThreshold(model)
+}
+
 export async function autoCompactIfNeeded(
   messages: Message[],
   toolUseContext: ToolUseContext,
@@ -276,6 +314,23 @@ export async function autoCompactIfNeeded(
     return { wasCompacted: false }
   }
 
+  // 方案2: turn throttle. If we compacted very recently, don't compact again
+  // for a few turns — give the context a chance to settle instead of
+  // re-summarizing every message. The hard blocking limit overrides this:
+  // when we're that close to the context window we must compact regardless,
+  // otherwise the next request risks a prompt-too-long failure.
+  if (tracking?.compacted === true && tracking.turnCounter < MIN_TURNS_BETWEEN_AUTO_COMPACT) {
+    const tokenCount =
+      tokenCountWithEstimation(messages) - (snipTokensFreed ?? 0)
+    const { isAtBlockingLimit } = calculateTokenWarningState(tokenCount, model)
+    if (shouldThrottleAutoCompact(tracking, isAtBlockingLimit)) {
+      logForDebugging(
+        `autocompact: throttled (turnsSinceCompact=${tracking.turnCounter} < ${MIN_TURNS_BETWEEN_AUTO_COMPACT}, not at blocking limit)`,
+      )
+      return { wasCompacted: false }
+    }
+  }
+
   const recompactionInfo: RecompactionInfo = {
     isRecompactionInChain: tracking?.compacted === true,
     turnsSincePreviousCompact: tracking?.turnCounter ?? -1,
@@ -306,6 +361,9 @@ export async function autoCompactIfNeeded(
     return {
       wasCompacted: true,
       compactionResult: sessionMemoryResult,
+      consecutiveFailures: isIneffectiveCompaction(sessionMemoryResult, model)
+        ? (tracking?.consecutiveFailures ?? 0) + 1
+        : 0,
     }
   }
 
@@ -325,10 +383,27 @@ export async function autoCompactIfNeeded(
     setLastSummarizedMessageId(undefined)
     runPostCompactCleanup(querySource)
 
+    // 方案1: if the compaction didn't actually get us under the threshold, count
+    // it toward the circuit breaker instead of resetting to 0. Otherwise a
+    // perpetually-over-threshold session re-compacts every single turn.
+    const ineffective = isIneffectiveCompaction(compactionResult, model)
+    if (ineffective) {
+      const nextFailures = (tracking?.consecutiveFailures ?? 0) + 1
+      logForDebugging(
+        `autocompact: ineffective compaction (postCompact=${compactionResult.truePostCompactTokenCount} >= threshold=${getAutoCompactThreshold(model)}); counting toward circuit breaker (${nextFailures}/${MAX_CONSECUTIVE_AUTOCOMPACT_FAILURES})`,
+        { level: 'warn' },
+      )
+      return {
+        wasCompacted: true,
+        compactionResult,
+        consecutiveFailures: nextFailures,
+      }
+    }
+
     return {
       wasCompacted: true,
       compactionResult,
-      // Reset failure count on success
+      // Reset failure count on a successful, effective compaction
       consecutiveFailures: 0,
     }
   } catch (error) {