diff --git a/core/pool_tls.c b/core/pool_tls.c
index c85c215e..baebb400 100644
--- a/core/pool_tls.c
+++ b/core/pool_tls.c
@@ -6,10 +6,15 @@
 #include <unistd.h>
 #include <stdatomic.h>
 #include "pool_tls_registry.h"
-
+#ifdef HAKMEM_POOL_TLS_BIND_BOX
+#include "pool_tls_bind.h"
+#else
+// gettid_cached is defined in pool_tls_bind.h when BIND_BOX is enabled
 static inline pid_t gettid_cached(void){
   static __thread pid_t t=0; if (__builtin_expect(t==0,0)) t=(pid_t)syscall(SYS_gettid); return t;
 }
+#endif
+
 #include <stdio.h>
 
 // Class sizes: 8KB, 16KB, 24KB, 32KB, 40KB, 48KB, 52KB
@@ -146,15 +151,30 @@ void pool_free(void* ptr) {
     // Need registry lookup (slower fallback) - not implemented in Phase 1
     return;
     #endif
+
     // Owner resolution via page registry
-    pid_t owner_tid=0; int reg_cls=-1;
-    if (pool_reg_lookup(ptr, &owner_tid, &reg_cls)){
-        pid_t me = gettid_cached();
-        if (owner_tid != me){
+    pid_t owner_tid = 0;
+    int reg_cls = -1;
+    if (pool_reg_lookup(ptr, &owner_tid, &reg_cls)) {
+#ifdef HAKMEM_POOL_TLS_BIND_BOX
+        // POOL_TLS_BIND_BOX: Fast TID comparison (no repeated gettid syscalls)
+        if (!pool_tls_is_mine_tid(owner_tid)) {
+            // Cross-thread free
             extern int pool_remote_push(int class_idx, void* ptr, int owner_tid);
             (void)pool_remote_push(class_idx, ptr, owner_tid);
             return;
         }
+        // Same-thread: Continue to fast free path below
+#else
+        // Original gettid comparison
+        pid_t me = gettid_cached();
+        if (owner_tid != me) {
+            // Cross-thread free
+            extern int pool_remote_push(int class_idx, void* ptr, int owner_tid);
+            (void)pool_remote_push(class_idx, ptr, owner_tid);
+            return;
+        }
+#endif
     }
 
     // Same-thread: Push to TLS freelist (2-3 instructions)
diff --git a/core/pool_tls_bind.c b/core/pool_tls_bind.c
new file mode 100644
index 00000000..cdba4768
--- /dev/null
+++ b/core/pool_tls_bind.c
@@ -0,0 +1,11 @@
+#include "pool_tls_bind.h"
+
+/**
+ * POOL_TLS_BIND_BOX - TID Cache Implementation
+ *
+ * This file provides the TLS storage for thread ID caching.
+ * All logic is inlined in pool_tls_bind.h for performance.
+ */
+
+// TLS storage (per-thread, automatically zero-initialized)
+__thread PoolTLSBind g_pool_tls_bind = {0};
diff --git a/core/pool_tls_bind.h b/core/pool_tls_bind.h
new file mode 100644
index 00000000..b08258fc
--- /dev/null
+++ b/core/pool_tls_bind.h
@@ -0,0 +1,56 @@
+#ifndef HAKMEM_POOL_TLS_BIND_H
+#define HAKMEM_POOL_TLS_BIND_H
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+/**
+ * POOL_TLS_BIND_BOX - TID Cache for Fast Same-Thread Detection
+ *
+ * Box Theory:
+ * - Boundary: Thread initialization - cache TID in TLS once
+ * - Internal: Hot path uses TID comparison (no gettid syscall)
+ * - Fallback: gettid_cached() on first access
+ *
+ * Performance:
+ * - Eliminates repeated gettid() calls from hot path
+ * - Simple TID comparison (1 comparison vs registry lookup)
+ * - Expected: Reduce cache misses and syscall overhead
+ */
+
+// TLS binding for fast TID caching
+typedef struct PoolTLSBind {
+    pid_t tid;  // My thread ID (cached, 0 = uninitialized)
+} PoolTLSBind;
+
+// TLS cache (per-thread, automatically zero-initialized)
+extern __thread PoolTLSBind g_pool_tls_bind;
+
+// Inline helper: gettid with caching
+static inline pid_t gettid_cached(void) {
+    static __thread pid_t cached_tid = 0;
+    if (__builtin_expect(cached_tid == 0, 0)) {
+        cached_tid = (pid_t)syscall(SYS_gettid);
+    }
+    return cached_tid;
+}
+
+// API
+
+// Get my thread ID (cached in TLS)
+static inline pid_t pool_get_my_tid(void) {
+    if (__builtin_expect(g_pool_tls_bind.tid == 0, 0)) {
+        g_pool_tls_bind.tid = gettid_cached();
+    }
+    return g_pool_tls_bind.tid;
+}
+
+// Fast same-thread check (TID comparison only)
+// Returns 1 if owner_tid matches my TID, 0 otherwise
+static inline int pool_tls_is_mine_tid(pid_t owner_tid) {
+    return owner_tid == pool_get_my_tid();
+}
+
+#endif // HAKMEM_POOL_TLS_BIND_H