claude-code - 💡(How to fix) Fix Auto-compact stopped working for third-party API providers since v2.1.161

// v2.1.150: feature flag resolver does NOT require Anthropic auth
function xU_() {
  if (!AT()) return false;                    // env/config check (passes)
  if (G28()) return false;                    // other check (passes)
  return V6("tengu_sepia_moth", false);       // feature flag → can resolve
}

// V6() → we() = !process.env.DISABLE_GROWTHBOOK && !OS()
// Does NOT check for Anthropic first-party authentication
// → GrowthBook is available, flag can be fetched/cached
// → tengu_sepia_moth resolves correctly → auto-compact works

---

// v2.1.161+: NEW auth gate added, blocks third-party users
function _Y8() {
  if (!AT()) return false;                    // env/config check (passes)
  if (!Os()) return false;                    // NEW: remote env check
  if (vl()) return false;                     // NEW: another feature flag check
  return D6("tengu_sepia_moth", false);       // feature flag → CANNOT resolve
}

// D6() → qu() → Au() → !LC() → !(dGL() || ...)
// dGL() = !Z7() where Z7() = (XA() === "firstParty")
// → Z7() returns false for third-party API users
// → dGL() returns true
// → LC() returns true
// → Au() returns false (GrowthBook "unavailable")
// → qu() returns false
// → D6("tengu_sepia_moth", false) returns the DEFAULT value: false
// → _Y8() returns false → Auto-compact NEVER triggers

---

ANTHROPIC_BASE_URL != api.anthropic.com
  → Z7() = false                    (not first-party auth)
    → dGL() = true                  (!Z7())
      → LC() = true                 (dGL() || ...)
        → Au() = false              (!LC())
          → qu() = false            (!DISABLE_GROWTHBOOK && Au())
            → D6("tengu_sepia_moth", false) returns false (default, GrowthBook unreachable)
              → _Y8() = false
                → SC_() = false     (auto-compact trigger check)
                  → Auto-compact NEVER fires ❌

---

// Anthropic first-party auth check
function Z7() { return XA() === "firstParty"; }

// GrowthBook availability - now gated on Anthropic auth
function dGL() {
  if (eH(process.env.CLAUDE_CODE_PROVIDER_MANAGED_BY_HOST)) return false;
  return !Z7();  // true when NOT first-party → blocks GrowthBook
}

// GrowthBook connectivity
function LC() { return dGL() || H3() !== null || wM6(); }
function Au() { return !LC(); }
function qu() { return !T6.DISABLE_GROWTHBOOK && Au(); }

// Feature flag resolver - returns default when GrowthBook unavailable
function D6(H, _) {
  let A = Hj6();              // local config override
  if (A && H in A) return A[H];
  let q = _j6();              // another config
  if (q && H in q) return q[H];
  if (!qu()) return _;        // ← BLOCKED HERE: returns default (false)
  // ... GrowthBook lookup (never reached)
}

// Auto-compact gate
function _Y8() {
  if (!AT()) return false;
  if (!Os()) return false;
  if (vl()) return false;
  return D6("tengu_sepia_moth", false);  // false = auto-compact disabled
}

// Should auto-compact trigger?
function SC_(H) {
  if (H.compactionResult !== undefined) return false;
  if (H.isPreFirstCompactFork) return false;
  if (H.consecutiveFailures !== undefined) return false;
  if (H.hasAttemptedReactiveCompact) return false;
  if (H.lastTransitionReason === "precomputed_compact_swap") return false;
  if (!_Y8()) return false;                                    // ← always false for 3rd party
  return ix9(H.contextTokens, H.model, H.autoCompactWindow);  // ← never reached
}

---

## Evidence from Session Transcripts

Analyzed 500+ session transcripts. The `compact_boundary` system events with `compactMetadata` clearly show the regression:

### All sessions with auto-compact (chronological):


v2.1.117 (May 7-14):   auto=38, manual=12  ✅ Working
v2.1.140 (May 14-24):  auto=89, manual=18  ✅ Working
v2.1.150 (May 24-Jun 3): auto=55, manual=14  ✅ Working
v2.1.161 (Jun 3):      auto=0,  manual=3   ❌ BROKEN
v2.1.162 (Jun 4-5):    auto=0,  manual=1   ❌ BROKEN


### Example: 20MB session (v2.1.140, May 22-23) — auto-compact worked:
14 auto-compactions, all `trigger: "auto"`, each with full metadata:

{"trigger": "auto", "preTokens": 153018, "postTokens": 9231, "durationMs": 57363}
{"trigger": "auto", "preTokens": 153032, "postTokens": 9150, "durationMs": 45430}
// ... 12 more, all auto-triggered at ~153k tokens


### Example: Recent sessions (v2.1.162, June 4) — auto-compact broken:

Session 60faa9d3: auto=0, manual=2, hard_limit_hits=5
  → User had to manually /compact, or hit "ran out of context" emergency recovery

Session 4daf00de: auto=0, manual=1, hard_limit_hits=1
  → Same pattern


After upgrade to v2.1.161+: zero auto-compacts. Sessions grow until API returns an error, then emergency recovery kicks in.

---

// .claude/settings.json
   {
     "env": {
       "ANTHROPIC_BASE_URL": "https://open.bigmodel.cn/api/anthropic",
       "ANTHROPIC_AUTH_TOKEN": "<third-party-token>",
       "ANTHROPIC_MODEL": "glm-5.1"
     }
   }

---

function _Y8() {
     if (eH(process.env.CLAUDE_CODE_ENABLE_AUTO_COMPACT)) return true;  // explicit override
     if (!AT()) return false;
     if (!Os()) return false;
     if (vl()) return false;
     return D6("tengu_sepia_moth", true);  // default true instead of false
   }