diff --git a/include/stellar/packet.h b/include/stellar/packet.h
index 8e9cf54..c20e1b5 100644
--- a/include/stellar/packet.h
+++ b/include/stellar/packet.h
@@ -136,21 +136,6 @@ int packet_get_tunnel_count(const struct packet *pkt);
 // return -1: failed
 int packet_get_tunnel_by_idx(const struct packet *pkt, int idx, struct tunnel *out);
 
-/******************************************************************************
- * build
- ******************************************************************************/
-
-/*
- * tcp_seq: the sequence number of the new TCP packet (in host byte order)
- * tcp_ack: the acknowledgment number of the new TCP packet (in host byte order)
- * tcp_options_len: the length of the options (must be a multiple of 4)
- */
-struct packet *packet_build_tcp(const struct packet *origin_pkt, uint32_t tcp_seq, uint32_t tcp_ack, uint8_t tcp_flags,
-                                const char *tcp_options, uint16_t tcp_options_len,
-                                const char *tcp_payload, uint16_t tcp_payload_len);
-struct packet *packet_build_udp(const struct packet *origin_pkt, const char *udp_payload, uint16_t udp_payload_len);
-struct packet *packet_build_l3(const struct packet *origin_pkt, uint8_t ip_proto, const char *l3_payload, uint16_t l3_payload_len);
-
 /******************************************************************************
  * utils
  ******************************************************************************/
@@ -183,6 +168,7 @@ enum packet_type
 };
 
 enum packet_type packet_get_type(const struct packet *pkt);
+void packet_set_type(struct packet *pkt, enum packet_type type);
 
 void packet_set_action(struct packet *pkt, enum packet_action action);
 enum packet_action packet_get_action(const struct packet *pkt);
@@ -228,6 +214,20 @@ typedef void on_packet_claimed_callback(struct packet *pkt, void *arg);
 int packet_manager_claim_packet(struct packet_manager *pkt_mgr, uint16_t thread_id, struct packet *pkt, on_packet_claimed_callback cb, void *arg);
 void packet_manager_schedule_packet(struct packet_manager *pkt_mgr, uint16_t thread_id, struct packet *pkt, enum packet_stage stage);
 
+/*
+ * tcp_seq: the sequence number of the new TCP packet (in host byte order)
+ * tcp_ack: the acknowledgment number of the new TCP packet (in host byte order)
+ * tcp_options_len: the length of the options (must be a multiple of 4)
+ */
+struct packet *packet_manager_build_tcp_packet(struct packet_manager *pkt_mgr, const struct packet *origin_pkt,
+                                               uint32_t tcp_seq, uint32_t tcp_ack, uint8_t tcp_flags,
+                                               const char *tcp_options, uint16_t tcp_options_len,
+                                               const char *tcp_payload, uint16_t tcp_payload_len);
+struct packet *packet_manager_build_udp_packet(struct packet_manager *pkt_mgr, const struct packet *origin_pkt,
+                                               const char *udp_payload, uint16_t udp_payload_len);
+struct packet *packet_manager_build_l3_packet(struct packet_manager *pkt_mgr, const struct packet *origin_pkt,
+                                              uint8_t ip_proto, const char *l3_payload, uint16_t l3_payload_len);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/infra/packet_manager/packet_builder.h b/infra/packet_manager/packet_builder.h
new file mode 100644
index 0000000..e05e140
--- /dev/null
+++ b/infra/packet_manager/packet_builder.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#include "stellar/packet.h"
+
+/*
+ * tcp_seq: the sequence number of the new TCP packet (in host byte order)
+ * tcp_ack: the acknowledgment number of the new TCP packet (in host byte order)
+ * tcp_options_len: the length of the options (must be a multiple of 4)
+ */
+struct packet *packet_build_tcp(const struct packet *origin_pkt, uint32_t tcp_seq, uint32_t tcp_ack, uint8_t tcp_flags,
+                                const char *tcp_options, uint16_t tcp_options_len,
+                                const char *tcp_payload, uint16_t tcp_payload_len);
+struct packet *packet_build_udp(const struct packet *origin_pkt, const char *udp_payload, uint16_t udp_payload_len);
+struct packet *packet_build_l3(const struct packet *origin_pkt, uint8_t ip_proto, const char *l3_payload, uint16_t l3_payload_len);
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/infra/packet_manager/packet_dabloom.h b/infra/packet_manager/packet_dabloom.h
index f19f78e..67f7624 100644
--- a/infra/packet_manager/packet_dabloom.h
+++ b/infra/packet_manager/packet_dabloom.h
@@ -5,7 +5,7 @@ extern "C"
 {
 #endif
 
-struct packet;
+#include "stellar/packet.h"
 
 // Duplicated Packet Filter for IPv4 Packet
 struct packet_dabloom;
diff --git a/infra/packet_manager/packet_internal.h b/infra/packet_manager/packet_internal.h
index d5903dc..8e6c5f5 100644
--- a/infra/packet_manager/packet_internal.h
+++ b/infra/packet_manager/packet_internal.h
@@ -127,7 +127,6 @@ uint16_t packet_get_link_id(const struct packet *pkt);
 void packet_set_claim(struct packet *pkt, bool claim);
 bool packet_is_claim(const struct packet *pkt);
 
-void packet_set_type(struct packet *pkt, enum packet_type type);
 void packet_set_direction(struct packet *pkt, enum packet_direction dir);
 
 void *packet_get_user_data(struct packet *pkt);
diff --git a/infra/packet_manager/packet_manager.c b/infra/packet_manager/packet_manager.c
index 46153cb..d615f64 100644
--- a/infra/packet_manager/packet_manager.c
+++ b/infra/packet_manager/packet_manager.c
@@ -3,6 +3,7 @@
 #include "utils_internal.h"
 #include "packet_internal.h"
 #include "packet_manager.h"
+#include "packet_builder.h"
 #include "fieldstat/fieldstat_easy.h"
 
 #define PACKET_MANAGER_LOG_ERROR(format, ...) STELLAR_LOG_ERROR(__thread_local_logger, "packet manager", format, ##__VA_ARGS__)
@@ -430,6 +431,60 @@ void packet_manager_print_stat(struct packet_manager *pkt_mgr, uint16_t thread_i
     }
 }
 
+struct packet *packet_manager_build_tcp_packet(struct packet_manager *pkt_mgr, const struct packet *origin_pkt, uint32_t tcp_seq, uint32_t tcp_ack, uint8_t tcp_flags,
+                                               const char *tcp_options, uint16_t tcp_options_len, const char *tcp_payload, uint16_t tcp_payload_len)
+{
+    struct packet *pkt = packet_build_tcp(origin_pkt, tcp_seq, tcp_ack, tcp_flags, tcp_options, tcp_options_len, tcp_payload, tcp_payload_len);
+    if (pkt == NULL)
+    {
+        return NULL;
+    }
+
+    struct exdata_runtime *ex_rte = exdata_runtime_new(pkt_mgr->sche->ex_sche);
+    packet_set_user_data(pkt, ex_rte);
+
+    return pkt;
+}
+
+struct packet *packet_manager_build_udp_packet(struct packet_manager *pkt_mgr, const struct packet *origin_pkt, const char *udp_payload, uint16_t udp_payload_len)
+{
+    struct packet *pkt = packet_build_udp(origin_pkt, udp_payload, udp_payload_len);
+    if (pkt == NULL)
+    {
+        return NULL;
+    }
+
+    struct exdata_runtime *ex_rte = exdata_runtime_new(pkt_mgr->sche->ex_sche);
+    packet_set_user_data(pkt, ex_rte);
+
+    return pkt;
+}
+
+struct packet *packet_manager_build_l3_packet(struct packet_manager *pkt_mgr, const struct packet *origin_pkt, uint8_t ip_proto, const char *l3_payload, uint16_t l3_payload_len)
+{
+    struct packet *pkt = packet_build_l3(origin_pkt, ip_proto, l3_payload, l3_payload_len);
+    if (pkt == NULL)
+    {
+        return NULL;
+    }
+
+    struct exdata_runtime *ex_rte = exdata_runtime_new(pkt_mgr->sche->ex_sche);
+    packet_set_user_data(pkt, ex_rte);
+
+    return pkt;
+}
+
+void packet_manager_free_packet(struct packet_manager *pkt_mgr __attribute__((unused)), struct packet *pkt)
+{
+    if (pkt)
+    {
+        struct exdata_runtime *ex_rte = packet_get_user_data(pkt);
+        exdata_runtime_free(ex_rte);
+
+        packet_free(pkt);
+    }
+}
+
 /******************************************************************************
  * packet manager module
  ******************************************************************************/
diff --git a/infra/packet_manager/packet_pool.h b/infra/packet_manager/packet_pool.h
index 422ace4..fd5424d 100644
--- a/infra/packet_manager/packet_pool.h
+++ b/infra/packet_manager/packet_pool.h
@@ -5,7 +5,7 @@ extern "C"
 {
 #endif
 
-#include <stdint.h>
+#include "stellar/packet.h"
 
 struct packet_pool;
 struct packet_pool *packet_pool_new(uint64_t capacity);
diff --git a/infra/packet_manager/test/gtest_packet_builder.cpp b/infra/packet_manager/test/gtest_packet_builder.cpp
index 18c8aac..b7e7686 100644
--- a/infra/packet_manager/test/gtest_packet_builder.cpp
+++ b/infra/packet_manager/test/gtest_packet_builder.cpp
@@ -6,6 +6,7 @@
 #include "packet_internal.h"
 #include "packet_dump.h"
 #include "packet_parser.h"
+#include "packet_builder.h"
 
 #define PRINT_GREEN(fmt, ...) printf("\033[0;32m" fmt "\033[0m\n", ##__VA_ARGS__)
 #define PRINT_RED(fmt, ...) printf("\033[0;31m" fmt "\033[0m\n", ##__VA_ARGS__)
diff --git a/infra/version.map b/infra/version.map
index 385a2a2..8560564 100644
--- a/infra/version.map
+++ b/infra/version.map
@@ -5,6 +5,8 @@ global:
 	packet_get_tunnel_count;
 	packet_get_tunnel_by_idx;
 	packet_prepend_sids;
+	packet_set_type;
+	packet_get_type;
 	packet_get_direction;
 	packet_set_action;
 	packet_get_action;
@@ -12,9 +14,6 @@ global:
 	packet_get_raw_len;
 	packet_get_payload_data;
 	packet_get_payload_len;
-	packet_build_tcp;
-	packet_build_udp;
-	packet_build_l3;
 	packet_manager_on_init;
 	packet_manager_on_exit;
 	packet_manager_on_thread_init;
@@ -23,6 +22,9 @@ global:
 	packet_manager_subscribe;
 	packet_manager_claim_packet;
 	packet_manager_schedule_packet;
+	packet_manager_build_tcp_packet;
+	packet_manager_build_udp_packet;
+	packet_manager_build_l3_packet;
 
 	session_is_symmetric;
 	session_has_duplicate_traffic;