diff --git a/include/cpp.h b/include/cpp.h
index 1b7ca25b8..8bd1b55a3 100644
--- a/include/cpp.h
+++ b/include/cpp.h
@@ -31,26 +31,22 @@
 #endif /* PROXYSQLCLICKHOUSE */
 
 #ifdef PROXYSQLGENAI
-#include "MCP_Tool_Handler.h"
 #include "AI_Features_Manager.h"
 #include "AI_Tool_Handler.h"
 #include "AI_Vector_Storage.h"
-#include "Admin_Tool_Handler.h"
 // Anomaly_Detector.h moved to plugins/genai/ in Step 3 of the GenAI
 // plugin carve-out; no core file should include it any more.
-#include "Cache_Tool_Handler.h"
-#include "Config_Tool_Handler.h"
+//
+// Step 4.C moved a further set of MCP-related headers into the genai
+// plugin: Admin/Cache/Config/Observe/Stats/MCP_Tool/MySQL/Query
+// tool handlers, MCP_Endpoint, MCP_Thread, ProxySQL_MCP_Server.
+// Their includes were removed from this aggregate header.
 #include "Discovery_Schema.h"
 #include "GenAI_Thread.h"
 #include "LLM_Bridge.h"
-#include "MCP_Endpoint.h"
-#include "MCP_Thread.h"
 #include "MySQL_Catalog.h"
-#include "MySQL_FTS.h"
-#include "MySQL_Tool_Handler.h"
-#include "Stats_Tool_Handler.h"
-#include "ProxySQL_MCP_Server.hpp"
-#include "Query_Tool_Handler.h"
+// MySQL_FTS.h moved to plugins/genai/ in Step 4.C (its bidirectional
+// coupling with MySQL_Tool_Handler forced the early move).
 #include "RAG_Tool_Handler.h"
 #include "PgSQL_Static_Harvester.h"
 #include "Static_Harvester.h"
diff --git a/lib/Admin_Bootstrap.cpp b/lib/Admin_Bootstrap.cpp
index 223571037..817e7bba2 100644
--- a/lib/Admin_Bootstrap.cpp
+++ b/lib/Admin_Bootstrap.cpp
@@ -192,7 +192,7 @@ extern MySQL_Monitor *GloMyMon;
 extern PgSQL_Threads_Handler* GloPTH;
 
 #ifdef PROXYSQLGENAI
-extern MCP_Threads_Handler* GloMCPH;
+// MCP_Threads_Handler ownership moved to the genai plugin in Step 4.C.
 extern GenAI_Threads_Handler* GloGATH;
 extern AI_Features_Manager *GloAI;
 #endif /* PROXYSQLGENAI */
diff --git a/lib/Admin_FlushVariables.cpp b/lib/Admin_FlushVariables.cpp
index 52e18e8ca..bcca178d7 100644
--- a/lib/Admin_FlushVariables.cpp
+++ b/lib/Admin_FlushVariables.cpp
@@ -25,8 +25,9 @@ using json = nlohmann::json;
 #include "proxysql.h"
 #include "proxysql_config.h"
 #include "proxysql_restapi.h"
-#include "MCP_Thread.h"
-#include "ProxySQL_MCP_Server.hpp"
+// MCP_Thread.h / ProxySQL_MCP_Server.hpp moved to the genai plugin in
+// Step 4.C.  flush_mcp_variables___*() are stubbed below until 4.F
+// re-routes them through the plugin command registry.
 #include "proxysql_utils.h"
 #include "prometheus_helpers.h"
 #include "cpp.h"
@@ -143,7 +144,7 @@ extern MySQL_Monitor *GloMyMon;
 extern PgSQL_Threads_Handler* GloPTH;
 
 #ifdef PROXYSQLGENAI
-extern MCP_Threads_Handler* GloMCPH;
+// MCP_Threads_Handler ownership moved to the genai plugin in Step 4.C.
 extern GenAI_Threads_Handler* GloGATH;
 extern AI_Features_Manager *GloAI;
 #endif /* PROXYSQLGENAI */
@@ -1409,45 +1410,34 @@ void ProxySQL_Admin::flush_admin_variables___runtime_to_database(SQLite3DB *db,
 
 #ifdef PROXYSQLGENAI
 // MCP (Model Context Protocol) VARIABLES
+//
+// Step 4.C of the GenAI plugin carve-out moved MCP_Threads_Handler ownership
+// to the genai plugin.  Both flush_mcp_variables___* functions are stubbed
+// to no-ops here; Step 4.F will reintroduce the data flow via the plugin
+// command registry (the plugin will register handlers for "SET mcp-* …"
+// and "LOAD MCP VARIABLES …" and core admin SQL will dispatch to those).
+//
+// Effect during the 4.C → 4.F window:
+//   - mcp-* admin variables persist in global_variables on disk but are
+//     NOT pushed into the running MCP listener at startup.
+//   - "LOAD MCP VARIABLES TO RUNTIME" / "FROM DISK" are no-ops.
+//   - The MCP listener uses its compiled-in defaults.
+// Acceptable temporary state — documented in the carve-out plan.
 void ProxySQL_Admin::flush_mcp_variables___database_to_runtime(SQLite3DB* db, bool replace, const std::string& checksum, const time_t epoch, bool lock) {
-	proxy_debug(PROXY_DEBUG_ADMIN, 4, "Flushing MCP variables. Replace:%d\n", replace);
-	if (GloMCPH == NULL) {
-		proxy_debug(PROXY_DEBUG_ADMIN, 4, "MCP handler not initialized, skipping MCP variables\n");
-		return;
-	}
-	char* error = NULL;
-	int cols = 0;
-	int affected_rows = 0;
-	SQLite3_result* resultset = NULL;
-	char* q = (char*)"SELECT variable_name, variable_value FROM global_variables WHERE variable_name LIKE 'mcp-%'";
-	db->execute_statement(q, &error, &cols, &affected_rows, &resultset);
-	if (error) {
-		proxy_error("Error on %s : %s\n", q, error);
-		return;
-	}
-	if (resultset) {
-		if (lock) wrlock();
-		for (std::vector<SQLite3_row*>::iterator it = resultset->rows.begin(); it != resultset->rows.end(); ++it) {
-			SQLite3_row* r = *it;
-			char* name = r->fields[0];
-			char* val = r->fields[1];
-			// Skip the 'mcp-' prefix
-			char* var_name = name + 4;
-			GloMCPH->set_variable(var_name, val);
-		}
-
-		// Update runtime_global_variables table to reflect current runtime state
-		flush_mcp_variables___runtime_to_database(admindb, false, false, false, true, false);
-
-		// Manage MCP server state
-		load_mcp_server();
-
-		if (lock) wrunlock();
-		delete resultset;
-	}
+	(void)db; (void)replace; (void)checksum; (void)epoch; (void)lock;
+	proxy_debug(PROXY_DEBUG_ADMIN, 4, "flush_mcp_variables___database_to_runtime: stubbed (Step 4.C); awaiting 4.F\n");
 }
 
 void ProxySQL_Admin::flush_mcp_variables___runtime_to_database(SQLite3DB* db, bool replace, bool del, bool onlyifempty, bool runtime, bool use_lock) {
+	(void)db; (void)replace; (void)del; (void)onlyifempty; (void)runtime; (void)use_lock;
+	proxy_debug(PROXY_DEBUG_ADMIN, 4, "flush_mcp_variables___runtime_to_database: stubbed (Step 4.C); awaiting 4.F\n");
+}
+
+#if 0  // Original implementation preserved below for 4.F reference; the
+       // body references GloMCPH (now plugin-owned) so it cannot compile
+       // in core.  Kept inside `#if 0` so a search for the original
+       // logic finds it next to the stub.
+void ProxySQL_Admin::flush_mcp_variables___runtime_to_database_ORIGINAL(SQLite3DB* db, bool replace, bool del, bool onlyifempty, bool runtime, bool use_lock) {
 	proxy_debug(PROXY_DEBUG_ADMIN, 4, "Flushing MCP variables. Replace:%d, Delete:%d, Only_If_Empty:%d, Runtime:%d\n", replace, del, onlyifempty, runtime);
 	if (GloMCPH == NULL) {
 		proxy_debug(PROXY_DEBUG_ADMIN, 4, "MCP handler not initialized, skipping MCP variables\n");
@@ -1544,4 +1534,5 @@ void ProxySQL_Admin::flush_mcp_variables___runtime_to_database(SQLite3DB* db, bo
 	}
 	free(varnames);
 }
+#endif // 0 — original flush_mcp_variables___runtime_to_database body for 4.F reference
 #endif /* PROXYSQLGENAI */
diff --git a/lib/Admin_Handler.cpp b/lib/Admin_Handler.cpp
index 87847b4d1..46ef0c4fd 100644
--- a/lib/Admin_Handler.cpp
+++ b/lib/Admin_Handler.cpp
@@ -45,7 +45,7 @@ using json = nlohmann::json;
 #endif /* PROXYSQL40 */
 #include "MySQL_Logger.hpp"
 #include "PgSQL_Logger.hpp"
-#include "MCP_Thread.h"
+// MCP_Thread.h moved to plugins/genai/include/ in Step 4.C.
 #include "GenAI_Thread.h"
 #include "SQLite3_Server.h"
 #include "Web_Interface.hpp"
@@ -158,7 +158,7 @@ extern MySQL_Monitor *GloMyMon;
 extern PgSQL_Threads_Handler* GloPTH;
 
 #ifdef PROXYSQLGENAI
-extern MCP_Threads_Handler* GloMCPH;
+// extern MCP_Threads_Handler* GloMCPH; — removed in Step 4.C.
 extern GenAI_Threads_Handler* GloGATH;
 extern AI_Features_Manager *GloAI;
 #endif /* PROXYSQLGENAI */
@@ -1164,8 +1164,9 @@ bool is_valid_global_variable(const char *var_name) {
 		return true;
 #endif /* PROXYSQLCLICKHOUSE */
 #ifdef PROXYSQLGENAI
-	} else if (strlen(var_name) > 4 && !strncmp(var_name, "mcp-", 4) && GloMCPH && GloMCPH->has_variable(var_name + 4)) {
-		return true;
+	// FIXME(4.F): mcp-* variables routed via plugin command registry.
+	// Until 4.F lands, "SET mcp-port=..." admin SQL returns "unknown
+	// variable" — temporary state documented in the carve-out plan.
 	} else if (strlen(var_name) > 6 && !strncmp(var_name, "genai-", 6) && GloGATH && GloGATH->has_variable(var_name + 6)) {
 		return true;
 #endif /* PROXYSQLGENAI */
@@ -2668,9 +2669,13 @@ bool admin_handler_command_load_or_save(char *query_no_space, unsigned int query
 				}
 				return false;
 			}
-			if (GloMCPH) {
-				GloMCPH->load_target_auth_map(resultset);
-			} else if (resultset) {
+			// FIXME(4.F): GloMCPH->load_target_auth_map(resultset)
+			// removed in Step 4.C.  4.F will route this via the plugin
+			// command registry.  Until then, "LOAD MCP PROFILES …" still
+			// updates the SQLite tables but the running plugin doesn't
+			// re-pick-up the new auth map — operator must restart for
+			// changes to take effect.  Documented in the carve-out plan.
+			if (resultset) {
 				delete resultset;
 			}
 			return true;
diff --git a/lib/Makefile b/lib/Makefile
index e13f2563b..d11e9d7cd 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -134,12 +134,14 @@ _OBJ_CXX += MySQLFFTO.oo PgSQLFFTO.oo
 endif
 
 # GenAI object files (conditionally included)
+# Step 4.C of the GenAI plugin carve-out moved the MCP subsystem
+# (MCP_Thread, MCP_Endpoint, ProxySQL_MCP_Server, the 8 non-AI/RAG
+# tool handlers) into plugins/genai/.  AI/RAG/discovery surface stays
+# in core for Steps 5/6.
 ifeq ($(PROXYSQLGENAI),1)
 _OBJ_CXX += GenAI_Thread.oo \
-	MCP_Thread.oo ProxySQL_MCP_Server.oo MCP_Endpoint.oo MCP_Tool_Handler.oo \
-	MySQL_Catalog.oo MySQL_Tool_Handler.oo MySQL_FTS.oo \
-	Config_Tool_Handler.oo Query_Tool_Handler.oo \
-	Admin_Tool_Handler.oo Cache_Tool_Handler.oo Stats_Tool_Handler.oo \
+	MCP_Tool_Handler.oo \
+	MySQL_Catalog.oo \
 	AI_Features_Manager.oo LLM_Bridge.oo LLM_Clients.oo AI_Vector_Storage.oo AI_Tool_Handler.oo \
 	RAG_Tool_Handler.oo \
 	Discovery_Schema.oo Static_Harvester.oo PgSQL_Static_Harvester.oo
diff --git a/lib/ProxySQL_Admin.cpp b/lib/ProxySQL_Admin.cpp
index c66701db2..5d97fc9b8 100644
--- a/lib/ProxySQL_Admin.cpp
+++ b/lib/ProxySQL_Admin.cpp
@@ -22,7 +22,7 @@ using json = nlohmann::json;
 #include "mysql.h"
 #include "proxysql_admin.h"
 #include "Discovery_Schema.h"
-#include "Query_Tool_Handler.h"
+// Query_Tool_Handler.h moved to plugins/genai/include/ in Step 4.C.
 #include "re2/re2.h"
 #include "re2/regexp.h"
 #include "proxysql.h"
@@ -45,8 +45,8 @@ using json = nlohmann::json;
 #include "ProxySQL_Statistics.hpp"
 #include "MySQL_Logger.hpp"
 #include "PgSQL_Logger.hpp"
-#include "MCP_Thread.h"
-#include "ProxySQL_MCP_Server.hpp"
+// MCP_Thread.h / ProxySQL_MCP_Server.hpp moved to plugins/genai/include/
+// in Step 4.C.  The MCP listener lifecycle is owned by the genai plugin.
 #include "SQLite3_Server.h"
 #include "Web_Interface.hpp"
 
@@ -332,7 +332,7 @@ extern MySQL_Monitor *GloMyMon;
 extern PgSQL_Threads_Handler* GloPTH;
 
 #ifdef PROXYSQLGENAI
-extern MCP_Threads_Handler* GloMCPH;
+// extern MCP_Threads_Handler* GloMCPH; — removed in Step 4.C.
 extern GenAI_Threads_Handler* GloGATH;
 extern AI_Features_Manager *GloAI;
 #endif /* PROXYSQLGENAI */
@@ -3157,40 +3157,14 @@ void ProxySQL_Admin::init_pgsql_variables() {
 
 #ifdef PROXYSQLGENAI
 void ProxySQL_Admin::init_mcp_variables() {
-	if (GloMCPH) {
-		flush_mcp_variables___runtime_to_database(configdb, false, false, false, false, false);
-		flush_mcp_variables___runtime_to_database(admindb, false, true, false, false, false);
-		flush_mcp_variables___database_to_runtime(admindb, true, "", 0);
-
-		// Load MCP target/auth profiles into runtime tables and then in-memory map.
-		admindb->execute("DELETE FROM runtime_mcp_auth_profiles");
-		admindb->execute("INSERT OR REPLACE INTO runtime_mcp_auth_profiles SELECT * FROM main.mcp_auth_profiles");
-		admindb->execute("DELETE FROM runtime_mcp_target_profiles");
-		admindb->execute("INSERT OR REPLACE INTO runtime_mcp_target_profiles SELECT * FROM main.mcp_target_profiles");
-
-		char* error = NULL;
-		int cols = 0;
-		int affected_rows = 0;
-		SQLite3_result* resultset = NULL;
-		const char* q =
-			"SELECT t.target_id, t.protocol, t.hostgroup_id, t.auth_profile_id,"
-			" t.max_rows, t.timeout_ms, t.allow_explain, t.allow_discovery, t.description,"
-			" a.db_username, a.db_password, a.default_schema"
-			" FROM runtime_mcp_target_profiles t"
-			" JOIN runtime_mcp_auth_profiles a ON a.auth_profile_id=t.auth_profile_id"
-			" WHERE t.active=1"
-			" ORDER BY t.target_id";
-		admindb->execute_statement(q, &error, &cols, &affected_rows, &resultset);
-		if (error) {
-			proxy_error("Failed to load MCP target auth map: %s\n", error);
-			free(error);
-			if (resultset) {
-				delete resultset;
-			}
-		} else {
-			GloMCPH->load_target_auth_map(resultset);
-		}
-	}
+	// FIXME(4.F/4.G): MCP variables / target-auth-map ownership moved to
+	// the genai plugin in Step 4.C.  This function becomes a no-op until
+	// 4.F wires the variable flow through the plugin command registry
+	// and 4.G moves the runtime_mcp_* table maintenance into
+	// register_table-owned admin SQL.  In the interim, the running MCP
+	// listener uses its compiled-in defaults and does not see admin
+	// SQL changes.  Documented in the carve-out plan.
+	proxy_debug(PROXY_DEBUG_ADMIN, 4, "init_mcp_variables: stubbed (Step 4.C); awaiting 4.F/4.G\n");
 }
 
 void ProxySQL_Admin::init_genai_variables() {
@@ -3652,9 +3626,18 @@ void ProxySQL_Admin::load_restapi_server() {
 
 #ifdef PROXYSQLGENAI
 void ProxySQL_Admin::load_mcp_server() {
+	// FIXME(4.F): MCP listener lifecycle moved to the genai plugin in
+	// Step 4.C; the plugin owns the MCP server's start/stop/reconfigure
+	// flow now.  This admin-side hook becomes a no-op.  4.F will wire
+	// "LOAD MCP VARIABLES TO RUNTIME" through the plugin command
+	// registry; until then, runtime reconfiguration of mcp-port etc.
+	// requires a process restart.
 	if (!all_modules_started) { return; }
-	if (GloMCPH == NULL) { return; }
+	proxy_debug(PROXY_DEBUG_ADMIN, 4, "load_mcp_server: stubbed (Step 4.C); awaiting 4.F\n");
+}
 
+#if 0  // Original load_mcp_server body preserved for 4.F reference.
+void ProxySQL_Admin::load_mcp_server_ORIGINAL() {
 	// Helper lambda to check if MCP port is available
 	const auto check_mcp_port = [&](int port, bool& port_free) -> void {
 		int e_port_check = check_port_availability(port, &port_free);
@@ -3774,6 +3757,7 @@ void ProxySQL_Admin::load_mcp_server() {
 		}
 	}
 }
+#endif // 0 — original load_mcp_server body for 4.F reference
 #endif /* PROXYSQLGENAI */
 
 void ProxySQL_Admin::load_http_server() {
@@ -8591,6 +8575,16 @@ char* ProxySQL_Admin::load_pgsql_firewall_to_runtime() {
 //
 #ifdef PROXYSQLGENAI
 char* ProxySQL_Admin::load_mcp_query_rules_to_runtime() {
+	// FIXME(4.F): MCP query rules now live with the genai plugin's
+	// Query_Tool_Handler.  This admin entry-point becomes a no-op
+	// (returning a sentinel error) until 4.F wires
+	// "LOAD MCP QUERY RULES TO RUNTIME" through the plugin command
+	// registry.
+	return (char*)"MCP query rules: command moved to genai plugin (Step 4.C); awaiting 4.F wiring";
+}
+
+#if 0  // Original body preserved for 4.F reference.
+char* ProxySQL_Admin::load_mcp_query_rules_to_runtime_ORIGINAL() {
 	unsigned long long curtime1 = monotonic_time();
 	char* error = NULL;
 	int cols = 0;
@@ -8641,6 +8635,7 @@ char* ProxySQL_Admin::load_mcp_query_rules_to_runtime() {
 
 	return NULL;
 }
+#endif // 0 — original load_mcp_query_rules_to_runtime body for 4.F reference
 
 // Save MCP query rules from runtime to database
 //
@@ -8658,6 +8653,17 @@ char* ProxySQL_Admin::load_mcp_query_rules_to_runtime() {
 //   - Manual runtime-to-memory save operation
 //
 void ProxySQL_Admin::save_mcp_query_rules_from_runtime(bool _runtime) {
+	(void)_runtime;
+	// FIXME(4.F): the runtime MCP query rules cache moved with
+	// Query_Tool_Handler into the genai plugin in Step 4.C.  Until 4.F
+	// reroutes "SAVE MCP QUERY RULES …" through the plugin command
+	// registry, this admin call is a no-op (the on-disk and runtime
+	// admin tables are NOT refreshed from the running plugin's cache).
+	proxy_debug(PROXY_DEBUG_ADMIN, 4, "save_mcp_query_rules_from_runtime: stubbed (Step 4.C); awaiting 4.F\n");
+}
+
+#if 0  // Original body preserved for 4.F reference.
+void ProxySQL_Admin::save_mcp_query_rules_from_runtime_ORIGINAL(bool _runtime) {
 	if (!GloMCPH) return;
 	Query_Tool_Handler* qth = GloMCPH->query_tool_handler;
 	if (!qth) return;
@@ -8738,6 +8744,7 @@ void ProxySQL_Admin::save_mcp_query_rules_from_runtime(bool _runtime) {
 		delete resultset;
 	}
 }
+#endif // 0 — original save_mcp_query_rules_from_runtime body for 4.F reference
 #endif /* PROXYSQLGENAI */
 
 char* ProxySQL_Admin::load_mysql_query_rules_to_runtime(SQLite3_result* SQLite3_query_rules_resultset, SQLite3_result* SQLite3_query_rules_fast_routing_resultset, const std::string& checksum, const time_t epoch) {
diff --git a/lib/ProxySQL_Admin_Stats.cpp b/lib/ProxySQL_Admin_Stats.cpp
index ee763ae19..359991fd7 100644
--- a/lib/ProxySQL_Admin_Stats.cpp
+++ b/lib/ProxySQL_Admin_Stats.cpp
@@ -21,8 +21,12 @@
 #include "MySQL_Logger.hpp"
 #include "PgSQL_Logger.hpp"
 #ifdef PROXYSQLGENAI
-#include "MCP_Thread.h"
-#include "Query_Tool_Handler.h"
+// MCP_Thread.h / Query_Tool_Handler.h moved to plugins/genai/include/
+// in Step 4.C.  RAG_Tool_Handler stays in core for Step 6 — its header
+// is included here only because the (now stubbed) MCP-stats functions
+// referenced GloMCPH->rag_tool_handler.  Once those stats functions
+// re-route through the plugin command registry (4.F), this include
+// can go too.
 #include "RAG_Tool_Handler.h"
 #endif /* PROXYSQLGENAI */
 #include <openssl/x509v3.h>
@@ -1679,6 +1683,19 @@ void ProxySQL_Admin::stats___proxysql_message_metrics(bool reset) {
 
 #ifdef PROXYSQLGENAI
 void ProxySQL_Admin::stats___mcp_query_tools_counters(bool reset) {
+	(void)reset;
+	// FIXME(4.F/4.G): MCP tool-usage stats now live with the genai
+	// plugin's Query_Tool_Handler / RAG_Tool_Handler.  Until 4.F wires
+	// the stats collection through the plugin command registry (or 4.G
+	// migrates the stats_mcp_* tables to the plugin), this admin call
+	// is a no-op.  The tables are still created by Admin_Bootstrap so
+	// SELECTs against them work, but they're empty until the plugin
+	// publishes data through its own pathway.
+	proxy_debug(PROXY_DEBUG_ADMIN, 4, "stats___mcp_query_tools_counters: stubbed (Step 4.C); awaiting 4.F\n");
+}
+
+#if 0  // Original body preserved for 4.F reference.
+void ProxySQL_Admin::stats___mcp_query_tools_counters_ORIGINAL(bool reset) {
 	if (!GloMCPH) return;
 
 	statsdb->execute("BEGIN");
@@ -1759,6 +1776,7 @@ void ProxySQL_Admin::stats___mcp_query_tools_counters(bool reset) {
 
 	statsdb->execute("COMMIT");
 }
+#endif // 0 — original stats___mcp_query_tools_counters body for 4.F reference
 #endif /* PROXYSQLGENAI */
 
 int ProxySQL_Admin::stats___save_mysql_query_digest_to_sqlite(
@@ -2720,6 +2738,14 @@ int ProxySQL_Admin::stats___save_pgsql_query_digest_to_sqlite(
 //   - max_time: Maximum execution time in microseconds
 #ifdef PROXYSQLGENAI
 void ProxySQL_Admin::stats___mcp_query_digest(bool reset) {
+	(void)reset;
+	// FIXME(4.F): MCP query-digest stats moved with Query_Tool_Handler
+	// to the genai plugin in Step 4.C.  No-op until 4.F.
+	proxy_debug(PROXY_DEBUG_ADMIN, 4, "stats___mcp_query_digest: stubbed (Step 4.C); awaiting 4.F\n");
+}
+
+#if 0  // Original body preserved for 4.F reference.
+void ProxySQL_Admin::stats___mcp_query_digest_ORIGINAL(bool reset) {
 	if (!GloMCPH) return;
 	Query_Tool_Handler* qth = GloMCPH->query_tool_handler;
 	if (!qth) return;
@@ -2836,6 +2862,7 @@ void ProxySQL_Admin::stats___mcp_query_digest(bool reset) {
 	statsdb->execute("COMMIT");
 	delete resultset;
 }
+#endif // 0 — original stats___mcp_query_digest body for 4.F reference
 #endif /* PROXYSQLGENAI */
 
 // Collect MCP query rules statistics
@@ -2854,6 +2881,13 @@ void ProxySQL_Admin::stats___mcp_query_digest(bool reset) {
 //
 #ifdef PROXYSQLGENAI
 void ProxySQL_Admin::stats___mcp_query_rules() {
+	// FIXME(4.F): MCP query-rules stats moved with Query_Tool_Handler
+	// to the genai plugin in Step 4.C.  No-op until 4.F.
+	proxy_debug(PROXY_DEBUG_ADMIN, 4, "stats___mcp_query_rules: stubbed (Step 4.C); awaiting 4.F\n");
+}
+
+#if 0  // Original body preserved for 4.F reference.
+void ProxySQL_Admin::stats___mcp_query_rules_ORIGINAL() {
 	if (!GloMCPH) return;
 	Query_Tool_Handler* qth = GloMCPH->query_tool_handler;
 	if (!qth) return;
@@ -2894,6 +2928,7 @@ void ProxySQL_Admin::stats___mcp_query_rules() {
 	statsdb->execute("COMMIT");
 	delete resultset;
 }
+#endif // 0 — original stats___mcp_query_rules body for 4.F reference
 #endif /* PROXYSQLGENAI */
 
 // Helper: convert ASN1_TIME to ISO 8601 string (YYYY-MM-DDTHH:MM:SSZ)
diff --git a/plugins/genai/Makefile b/plugins/genai/Makefile
index 52dc74d2f..962573c14 100644
--- a/plugins/genai/Makefile
+++ b/plugins/genai/Makefile
@@ -71,15 +71,28 @@ SRCS := $(PLUGIN_DIR)/src/plugin_main.cpp \
 	$(PLUGIN_DIR)/src/plugin_hooks.cpp \
 	$(PLUGIN_DIR)/src/Anomaly_Detector.cpp \
 	$(PLUGIN_DIR)/src/backend_client.cpp \
-	$(PLUGIN_DIR)/src/local_proxy_endpoint.cpp
+	$(PLUGIN_DIR)/src/local_proxy_endpoint.cpp \
+	$(PLUGIN_DIR)/src/MCP_Endpoint.cpp \
+	$(PLUGIN_DIR)/src/MCP_Thread.cpp \
+	$(PLUGIN_DIR)/src/MySQL_FTS.cpp \
+	$(PLUGIN_DIR)/src/ProxySQL_MCP_Server.cpp \
+	$(PLUGIN_DIR)/src/tool_handlers/Admin_Tool_Handler.cpp \
+	$(PLUGIN_DIR)/src/tool_handlers/Cache_Tool_Handler.cpp \
+	$(PLUGIN_DIR)/src/tool_handlers/Config_Tool_Handler.cpp \
+	$(PLUGIN_DIR)/src/tool_handlers/MySQL_Tool_Handler.cpp \
+	$(PLUGIN_DIR)/src/tool_handlers/Observe_Tool_Handler.cpp \
+	$(PLUGIN_DIR)/src/tool_handlers/Query_Tool_Handler.cpp \
+	$(PLUGIN_DIR)/src/tool_handlers/Stats_Tool_Handler.cpp
 HEADERS := $(wildcard $(PLUGIN_DIR)/include/*.h) \
 	$(PROXYSQL_PATH)/include/ProxySQL_Plugin.h
 OBJS := $(patsubst $(PLUGIN_DIR)/src/%.cpp,$(ODIR)/%.o,$(SRCS))
 
 $(ODIR):
 	mkdir -p $(ODIR)
+	mkdir -p $(ODIR)/tool_handlers
 
 $(ODIR)/%.o: $(PLUGIN_DIR)/src/%.cpp $(HEADERS) | $(ODIR)
+	@mkdir -p $(dir $@)
 	$(CXX) -c -o $@ $< $(CXXFLAGS) $(IDIRS)
 
 $(PLUGIN_SO): $(OBJS)
diff --git a/include/Admin_Tool_Handler.h b/plugins/genai/include/Admin_Tool_Handler.h
similarity index 100%
rename from include/Admin_Tool_Handler.h
rename to plugins/genai/include/Admin_Tool_Handler.h
diff --git a/include/Cache_Tool_Handler.h b/plugins/genai/include/Cache_Tool_Handler.h
similarity index 100%
rename from include/Cache_Tool_Handler.h
rename to plugins/genai/include/Cache_Tool_Handler.h
diff --git a/include/Config_Tool_Handler.h b/plugins/genai/include/Config_Tool_Handler.h
similarity index 100%
rename from include/Config_Tool_Handler.h
rename to plugins/genai/include/Config_Tool_Handler.h
diff --git a/include/MCP_Endpoint.h b/plugins/genai/include/MCP_Endpoint.h
similarity index 100%
rename from include/MCP_Endpoint.h
rename to plugins/genai/include/MCP_Endpoint.h
diff --git a/include/MCP_Thread.h b/plugins/genai/include/MCP_Thread.h
similarity index 100%
rename from include/MCP_Thread.h
rename to plugins/genai/include/MCP_Thread.h
diff --git a/include/MySQL_FTS.h b/plugins/genai/include/MySQL_FTS.h
similarity index 100%
rename from include/MySQL_FTS.h
rename to plugins/genai/include/MySQL_FTS.h
diff --git a/include/MySQL_Tool_Handler.h b/plugins/genai/include/MySQL_Tool_Handler.h
similarity index 100%
rename from include/MySQL_Tool_Handler.h
rename to plugins/genai/include/MySQL_Tool_Handler.h
diff --git a/include/Observe_Tool_Handler.h b/plugins/genai/include/Observe_Tool_Handler.h
similarity index 100%
rename from include/Observe_Tool_Handler.h
rename to plugins/genai/include/Observe_Tool_Handler.h
diff --git a/include/ProxySQL_MCP_Server.hpp b/plugins/genai/include/ProxySQL_MCP_Server.hpp
similarity index 100%
rename from include/ProxySQL_MCP_Server.hpp
rename to plugins/genai/include/ProxySQL_MCP_Server.hpp
diff --git a/include/Query_Tool_Handler.h b/plugins/genai/include/Query_Tool_Handler.h
similarity index 100%
rename from include/Query_Tool_Handler.h
rename to plugins/genai/include/Query_Tool_Handler.h
diff --git a/include/Stats_Tool_Handler.h b/plugins/genai/include/Stats_Tool_Handler.h
similarity index 100%
rename from include/Stats_Tool_Handler.h
rename to plugins/genai/include/Stats_Tool_Handler.h
diff --git a/plugins/genai/include/genai_plugin.h b/plugins/genai/include/genai_plugin.h
index 618e416b7..469258916 100644
--- a/plugins/genai/include/genai_plugin.h
+++ b/plugins/genai/include/genai_plugin.h
@@ -24,6 +24,7 @@
 
 namespace prometheus { class Counter; }
 class Anomaly_Detector;
+class MCP_Threads_Handler;
 
 /**
  * @brief Process-wide state shared across the plugin's translation units.
@@ -54,6 +55,13 @@ struct GenAIPluginContext {
 	/// Prometheus counter for anomalies that were *blocked* (DENY
 	/// returned to the client).  Same lifetime rules as above.
 	prometheus::Counter* metric_blocked_queries { nullptr };
+
+	/// MCP listener handler.  Replaces the former core global
+	/// `GloMCPH` as of Step 4.C.  Constructed in `genai_init()`,
+	/// started by `genai_start()`, torn down by `genai_stop()`.
+	/// See plugins/genai/src/MCP_Thread.cpp for the listener
+	/// implementation.
+	MCP_Threads_Handler* mcp { nullptr };
 };
 
 /**
diff --git a/lib/MCP_Endpoint.cpp b/plugins/genai/src/MCP_Endpoint.cpp
similarity index 100%
rename from lib/MCP_Endpoint.cpp
rename to plugins/genai/src/MCP_Endpoint.cpp
diff --git a/lib/MCP_Thread.cpp b/plugins/genai/src/MCP_Thread.cpp
similarity index 100%
rename from lib/MCP_Thread.cpp
rename to plugins/genai/src/MCP_Thread.cpp
diff --git a/lib/MySQL_FTS.cpp b/plugins/genai/src/MySQL_FTS.cpp
similarity index 100%
rename from lib/MySQL_FTS.cpp
rename to plugins/genai/src/MySQL_FTS.cpp
diff --git a/lib/ProxySQL_MCP_Server.cpp b/plugins/genai/src/ProxySQL_MCP_Server.cpp
similarity index 75%
rename from lib/ProxySQL_MCP_Server.cpp
rename to plugins/genai/src/ProxySQL_MCP_Server.cpp
index 29a01b338..269da119a 100644
--- a/lib/ProxySQL_MCP_Server.cpp
+++ b/plugins/genai/src/ProxySQL_MCP_Server.cpp
@@ -14,6 +14,16 @@ using json = nlohmann::json;
 #include "Admin_Tool_Handler.h"
 #include "Cache_Tool_Handler.h"
 #include "Stats_Tool_Handler.h"
+// AI_Tool_Handler / RAG_Tool_Handler stay in core for Steps 5 / 6.
+// We still include their headers because MCP_Threads_Handler has
+// `AI_Tool_Handler*` and `RAG_Tool_Handler*` member fields that need
+// the full class definitions to be visible in this TU.  Their
+// *constructions* below are wrapped in `#if 0` so the plugin .so
+// doesn't take an unresolved reference to their constructors at
+// dlopen time (host proxysql doesn't currently re-export those
+// constructors from libproxysql.a since nothing in core calls them
+// after the carve-out move).  Steps 5 / 6 move the classes into
+// the plugin and the wrapped blocks get re-enabled.
 #include "AI_Tool_Handler.h"
 #include "RAG_Tool_Handler.h"
 #include "AI_Features_Manager.h"
@@ -137,26 +147,11 @@ ProxySQL_MCP_Server::ProxySQL_MCP_Server(int p, MCP_Threads_Handler* h)
 		handler->stats_tool_handler = NULL;
 	}
 
-	// 6. AI Tool Handler (for LLM and other AI features).  In Step 3
-	// of the GenAI plugin carve-out, the Anomaly_Detector moved to
-	// plugins/genai/ and AI_Features_Manager no longer holds one;
-	// AI_Tool_Handler's anomaly_detector field was removed (it was
-	// stored but never read), so the constructor now takes only the
-	// LLM_Bridge.
-	extern AI_Features_Manager *GloAI;
-	if (GloAI) {
-		handler->ai_tool_handler = new AI_Tool_Handler(GloAI->get_llm_bridge());
-		if (handler->ai_tool_handler->init() == 0) {
-			proxy_info("AI Tool Handler initialized\n");
-		} else {
-			proxy_error("Failed to initialize AI Tool Handler\n");
-			delete handler->ai_tool_handler;
-			handler->ai_tool_handler = NULL;
-		}
-	} else {
-		proxy_warning("AI_Features_Manager not available, AI Tool Handler not initialized\n");
-		handler->ai_tool_handler = NULL;
-	}
+	// 6. AI Tool Handler — disabled during the 4.C → 5 window.
+	// AI_Tool_Handler still lives in lib/, and the plugin .so cannot
+	// take an unresolved reference to its constructor (see the include
+	// block at the top of this file for the dlopen rationale).
+	handler->ai_tool_handler = nullptr;
 
 	// Register MCP endpoints
 	// Each endpoint gets its own dedicated tool handler
@@ -178,34 +173,13 @@ ProxySQL_MCP_Server::ProxySQL_MCP_Server(int p, MCP_Threads_Handler* h)
 	register_endpoint("/mcp/admin", handler->admin_tool_handler, "admin");
 	register_endpoint("/mcp/cache", handler->cache_tool_handler, "cache");
 
-	// 6. AI endpoint (for LLM and other AI features)
-	if (handler->ai_tool_handler) {
-		std::unique_ptr<httpserver::http_resource> ai_resource =
-			std::unique_ptr<httpserver::http_resource>(new MCP_JSONRPC_Resource(handler, handler->ai_tool_handler, "ai"));
-		ws->register_resource("/mcp/ai", ai_resource.get(), true);
-		_endpoints.push_back({"/mcp/ai", std::move(ai_resource)});
-	}
+	// AI endpoint registration omitted in 4.C-merged (ai_tool_handler
+	// always null until Step 5 moves AI_Tool_Handler into the plugin).
 
-	// 7. RAG endpoint (for Retrieval-Augmented Generation)
-	if (GloAI) {
-		// Use same catalog path as query_tool_handler for logging
-		std::string catalog_path = std::string(GloVars.datadir) + "/mcp_catalog.db";
-		handler->rag_tool_handler = new RAG_Tool_Handler(GloAI, catalog_path);
-		if (handler->rag_tool_handler->init() == 0) {
-			std::unique_ptr<httpserver::http_resource> rag_resource =
-				std::unique_ptr<httpserver::http_resource>(new MCP_JSONRPC_Resource(handler, handler->rag_tool_handler, "rag"));
-			ws->register_resource("/mcp/rag", rag_resource.get(), true);
-			_endpoints.push_back({"/mcp/rag", std::move(rag_resource)});
-			proxy_info("RAG Tool Handler initialized\n");
-		} else {
-			proxy_error("Failed to initialize RAG Tool Handler\n");
-			delete handler->rag_tool_handler;
-			handler->rag_tool_handler = NULL;
-		}
-	} else {
-		proxy_warning("AI_Features_Manager not available, RAG Tool Handler not initialized\n");
-		handler->rag_tool_handler = NULL;
-	}
+	// 7. RAG endpoint — disabled during the 4.C → 6 window for the
+	// same reason as AI above.  Step 6 moves RAG_Tool_Handler into the
+	// plugin and the /mcp/rag endpoint comes back online.
+	handler->rag_tool_handler = nullptr;
 
 	std::string endpoints_list;
 	for (size_t i = 0; i < _endpoints.size(); i++) {
@@ -266,19 +240,9 @@ ProxySQL_MCP_Server::~ProxySQL_MCP_Server() {
 			handler->stats_tool_handler = NULL;
 		}
 
-		// Clean up AI Tool Handler (uses shared components, don't delete them)
-		if (handler->ai_tool_handler) {
-			proxy_info("Cleaning up AI Tool Handler...\n");
-			delete handler->ai_tool_handler;
-			handler->ai_tool_handler = NULL;
-		}
-
-		// Clean up RAG Tool Handler
-		if (handler->rag_tool_handler) {
-			proxy_info("Cleaning up RAG Tool Handler...\n");
-			delete handler->rag_tool_handler;
-			handler->rag_tool_handler = NULL;
-		}
+		// AI / RAG cleanup omitted in 4.C-merged: ai_tool_handler and
+		// rag_tool_handler are always null because their constructions
+		// are wrapped in `#if 0` above.  Re-enabled in Steps 5 / 6.
 	}
 }
 
diff --git a/plugins/genai/src/plugin_main.cpp b/plugins/genai/src/plugin_main.cpp
index d501b8d90..96036d6c3 100644
--- a/plugins/genai/src/plugin_main.cpp
+++ b/plugins/genai/src/plugin_main.cpp
@@ -33,6 +33,7 @@
 
 #include "genai_plugin.h"
 #include "Anomaly_Detector.h"
+#include "MCP_Thread.h"
 
 #include "prometheus/counter.h"
 #include "prometheus/family.h"
@@ -40,6 +41,13 @@
 
 #include <cstdio>
 
+// Plugin-local definition of the MCP_Threads_Handler global, replacing
+// the core-side `GloMCPH` deleted in Step 4.C.  This stays inside the
+// .so — the plugin's tool handlers (Query_Tool_Handler etc.) reference
+// the symbol locally; core code never sees it.  Lifetime is managed by
+// `genai_init` / `genai_stop` below.
+MCP_Threads_Handler *GloMCPH = nullptr;
+
 namespace {
 
 /**
@@ -96,6 +104,7 @@ bool genai_init(ProxySQL_PluginServices* services) {
 	ctx.services = services;
 	ctx.started = false;
 	ctx.anomaly_detector = nullptr;
+	ctx.mcp = nullptr;
 
 	(void)register_prometheus_counters(ctx);
 	// Counter registration failure is non-fatal: it just means metrics
@@ -115,6 +124,17 @@ bool genai_init(ProxySQL_PluginServices* services) {
 		ctx.anomaly_detector = nullptr;
 		return false;
 	}
+
+	// Step 4.C: take over MCP_Threads_Handler ownership from former
+	// core global GloMCPH.  Construct here; `init()` is called below.
+	// `start()` (the listener launch) happens in genai_start().
+	//
+	// admindb access is not yet available during init() per the chassis
+	// ABI (services->get_admindb() returns nullptr until start()), so
+	// any plugin-side state that needs it must defer to genai_start.
+	ctx.mcp = new MCP_Threads_Handler();
+	GloMCPH = ctx.mcp;  // legacy alias used by Query_Tool_Handler etc.
+	ctx.mcp->init();
 	return true;
 }
 
@@ -131,6 +151,13 @@ bool genai_init(ProxySQL_PluginServices* services) {
 bool genai_start() {
 	GenAIPluginContext& ctx = genai_context();
 	ctx.started = true;
+	// FIXME(4.F): the MCP listener (ProxySQL_MCP_Server) does not
+	// auto-start here.  Pre-4.C, the listener came up via
+	// ProxySQL_Admin::load_mcp_server() driven off the mcp-enabled
+	// admin variable.  That admin surface is stubbed in core during
+	// the 4.C → 4.F window; consequently MCP runs with default
+	// (mcp_enabled=false) and stays idle.  4.F restores the admin
+	// SQL → plugin path and the listener auto-starts again.
 	return true;
 }
 
@@ -147,6 +174,14 @@ bool genai_start() {
 bool genai_stop() {
 	GenAIPluginContext& ctx = genai_context();
 	ctx.started = false;
+	if (ctx.mcp != nullptr) {
+		// MCP listener teardown.  ~MCP_Threads_Handler stops the
+		// embedded ProxySQL_MCP_Server (if running) and joins worker
+		// threads.  Mirrors the pre-4.C `delete GloMCPH` in main.cpp.
+		delete ctx.mcp;
+		ctx.mcp = nullptr;
+		GloMCPH = nullptr;
+	}
 	if (ctx.anomaly_detector != nullptr) {
 		ctx.anomaly_detector->close();
 		delete ctx.anomaly_detector;
diff --git a/lib/Admin_Tool_Handler.cpp b/plugins/genai/src/tool_handlers/Admin_Tool_Handler.cpp
similarity index 100%
rename from lib/Admin_Tool_Handler.cpp
rename to plugins/genai/src/tool_handlers/Admin_Tool_Handler.cpp
diff --git a/lib/Cache_Tool_Handler.cpp b/plugins/genai/src/tool_handlers/Cache_Tool_Handler.cpp
similarity index 100%
rename from lib/Cache_Tool_Handler.cpp
rename to plugins/genai/src/tool_handlers/Cache_Tool_Handler.cpp
diff --git a/lib/Config_Tool_Handler.cpp b/plugins/genai/src/tool_handlers/Config_Tool_Handler.cpp
similarity index 100%
rename from lib/Config_Tool_Handler.cpp
rename to plugins/genai/src/tool_handlers/Config_Tool_Handler.cpp
diff --git a/lib/MySQL_Tool_Handler.cpp b/plugins/genai/src/tool_handlers/MySQL_Tool_Handler.cpp
similarity index 100%
rename from lib/MySQL_Tool_Handler.cpp
rename to plugins/genai/src/tool_handlers/MySQL_Tool_Handler.cpp
diff --git a/lib/Observe_Tool_Handler.cpp b/plugins/genai/src/tool_handlers/Observe_Tool_Handler.cpp
similarity index 100%
rename from lib/Observe_Tool_Handler.cpp
rename to plugins/genai/src/tool_handlers/Observe_Tool_Handler.cpp
diff --git a/lib/Query_Tool_Handler.cpp b/plugins/genai/src/tool_handlers/Query_Tool_Handler.cpp
similarity index 100%
rename from lib/Query_Tool_Handler.cpp
rename to plugins/genai/src/tool_handlers/Query_Tool_Handler.cpp
diff --git a/lib/Stats_Tool_Handler.cpp b/plugins/genai/src/tool_handlers/Stats_Tool_Handler.cpp
similarity index 100%
rename from lib/Stats_Tool_Handler.cpp
rename to plugins/genai/src/tool_handlers/Stats_Tool_Handler.cpp
diff --git a/src/Makefile b/src/Makefile
index e7e637975..0ea6e324e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -195,7 +195,7 @@ $(ODIR)/%.o: %.cpp
 
 $(EXECUTABLE): $(ODIR) $(OBJ) $(LIBPROXYSQLAR)
 ifeq ($(PROXYSQLCLICKHOUSE),1)
-	$(CXX) -o $@ $(OBJ) $(CLANGFIX) $(LIBPROXYSQLAR) $(CLICKHOUSE_CPP_LDIR)/libclickhouse-cpp-lib.a $(LZ4_LDIR)/liblz4.a $(MYCXXFLAGS) $(CXXFLAGS) $(LDIRS) $(LIBS) $(MYLIBS)
+	$(CXX) -o $@ $(OBJ) $(CLANGFIX) -Wl,--whole-archive $(PROXYSQL_LDIR)/libproxysql.a -Wl,--no-whole-archive $(filter-out $(PROXYSQL_LDIR)/libproxysql.a,$(LIBPROXYSQLAR)) $(CLICKHOUSE_CPP_LDIR)/libclickhouse-cpp-lib.a $(LZ4_LDIR)/liblz4.a $(MYCXXFLAGS) $(CXXFLAGS) $(LDIRS) $(LIBS) $(MYLIBS)
 else
 	$(CXX) -o $@ $(OBJ) $(CLANGFIX) $(LIBPROXYSQLAR) $(MYCXXFLAGS) $(CXXFLAGS) $(LDIRS) $(LIBS) $(MYLIBS)
 endif
diff --git a/src/main.cpp b/src/main.cpp
index d8189b8a4..39559e5e7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -30,7 +30,8 @@ using json = nlohmann::json;
 #include "PgSQL_Logger.hpp"
 
 #ifdef PROXYSQLGENAI
-#include "MCP_Thread.h"
+// MCP_Thread.h has moved to plugins/genai/include/ as of Step 4.C.
+// Core no longer references MCP_Threads_Handler — the plugin owns it.
 #include "GenAI_Thread.h"
 #include "AI_Features_Manager.h"
 #endif /* PROXYSQLGENAI */
@@ -499,7 +500,8 @@ MySQL_Threads_Handler *GloMTH = NULL;
 PgSQL_Threads_Handler* GloPTH = NULL;
 
 #ifdef PROXYSQLGENAI
-MCP_Threads_Handler* GloMCPH = NULL;
+// GloMCPH removed in Step 4.C — the genai plugin owns the
+// MCP_Threads_Handler now.  GloGATH / GloAI follow in Step 5.
 GenAI_Threads_Handler* GloGATH = NULL;
 AI_Features_Manager *GloAI = NULL;
 #endif /* PROXYSQLGENAI */
@@ -932,7 +934,9 @@ void ProxySQL_Main_init_main_modules() {
 	GloPgAuth=NULL;
 	GloPTH=NULL;
 #ifdef PROXYSQLGENAI
-	GloMCPH=new MCP_Threads_Handler();
+	// MCP_Threads_Handler is now constructed by the genai plugin's
+	// init() callback (Step 4.C).  GenAI_Threads_Handler / AI_Features
+	// move similarly in Step 5.
 	GloGATH=new GenAI_Threads_Handler();
 	GloAI=NULL;
 #endif /* PROXYSQLGENAI */
@@ -978,10 +982,9 @@ void ProxySQL_Main_init_GenAI_module() {
 	proxy_info("AI Features module initialized\n");
 }
 
-void ProxySQL_Main_init_MCP_module() {
-	GloMCPH->init();
-	proxy_info("MCP module initialized\n");
-}
+// ProxySQL_Main_init_MCP_module() removed in Step 4.C.
+// The MCP listener is now started by the genai plugin's start()
+// callback (see plugins/genai/src/plugin_main.cpp).
 #endif /* PROXYSQLGENAI */
 
 void ProxySQL_Main_init_Admin_module(const bootstrap_info_t& bootstrap_info) {
@@ -1316,14 +1319,7 @@ void ProxySQL_Main_shutdown_all_modules() {
 #endif
 	}
 #ifdef PROXYSQLGENAI
-	if (GloMCPH) {
-		cpu_timer t;
-		delete GloMCPH;
-		GloMCPH = NULL;
-#ifdef DEBUG
-		std::cerr << "GloMCPH shutdown in ";
-#endif
-	}
+	// MCP shutdown is performed by the genai plugin's stop() callback (Step 4.C).
 	if (GloGATH) {
 		cpu_timer t;
 		delete GloGATH;
@@ -1568,7 +1564,7 @@ void ProxySQL_Main_init_phase2___not_started(const bootstrap_info_t& boostrap_in
 
 #ifdef PROXYSQLGENAI
 	ProxySQL_Main_init_GenAI_module();
-	ProxySQL_Main_init_MCP_module();
+	// MCP module init moved to the genai plugin (Step 4.C).
 #endif /* PROXYSQLGENAI */
 
 #ifdef PROXYSQL40
@@ -1800,9 +1796,10 @@ bool ProxySQL_Main_init_phase3___start_all() {
 	// GenAI
 	if (GloGATH)
 		GloAdmin->init_genai_variables();
-	if (GloMCPH) {
-		GloAdmin->init_mcp_variables();
-	}
+	// init_mcp_variables() moved to the genai plugin (Step 4.C).
+	// FIXME(4.F): the mcp-* admin SQL surface (SET mcp-port=...,
+	// LOAD MCP PROFILES ...) is non-functional between Step 4.C and
+	// Step 4.F.  Tracked in the carve-out plan.
 #endif /* PROXYSQLGENAI */
 
 	// HTTP Server should be initialized after other modules. See #4510
diff --git a/test/tap/test_helpers/test_globals.cpp b/test/tap/test_helpers/test_globals.cpp
index 29e22d517..e223867bf 100644
--- a/test/tap/test_helpers/test_globals.cpp
+++ b/test/tap/test_helpers/test_globals.cpp
@@ -49,7 +49,9 @@ using json = nlohmann::json;
 #include "PgSQL_Logger.hpp"
 
 #ifdef PROXYSQLGENAI
-#include "MCP_Thread.h"
+// MCP_Thread.h moved to plugins/genai/include/ in Step 4.C; the test
+// harness no longer needs to declare MCP_Threads_Handler at all (the
+// stub global below was removed too).
 #include "GenAI_Thread.h"
 #include "AI_Features_Manager.h"
 #endif /* PROXYSQLGENAI */
@@ -94,7 +96,8 @@ MySQL_Threads_Handler *GloMTH = nullptr;
 PgSQL_Threads_Handler *GloPTH = nullptr;
 
 #ifdef PROXYSQLGENAI
-MCP_Threads_Handler *GloMCPH = nullptr;
+// MCP_Threads_Handler *GloMCPH stub removed in Step 4.C — core no
+// longer references the symbol, so the test harness shouldn't either.
 GenAI_Threads_Handler *GloGATH = nullptr;
 AI_Features_Manager *GloAI = nullptr;
 #endif /* PROXYSQLGENAI */
diff --git a/test/tap/tests/unit/Makefile b/test/tap/tests/unit/Makefile
index a1053f047..098b6eb1e 100644
--- a/test/tap/tests/unit/Makefile
+++ b/test/tap/tests/unit/Makefile
@@ -154,7 +154,7 @@ else
 LIBPROXYSQLAR_FULL := $(LIBPROXYSQLAR)
 
 MYLIBS := -Wl,--export-dynamic -Wl,-Bdynamic -lgnutls -lcurl -lssl -lcrypto -luuid \
-		  -Wl,-Bstatic -lconfig -lproxysql -ldaemon -lconfig++ -lre2 -lpcrecpp -lpcre \
+		  -Wl,-Bstatic -lconfig -Wl,--whole-archive -lproxysql -Wl,--no-whole-archive -ldaemon -lconfig++ -lre2 -lpcrecpp -lpcre \
 		  -lmariadbclient -lhttpserver -lmicrohttpd -linjection -lev \
 		  -lprometheus-cpp-pull -lprometheus-cpp-core \
 		  -Wl,-Bstatic -lpq -lpgcommon -lpgport \