Disable sessions support by default (use -L to enable this)

Author: radare

src/main.c

@@ -49,6 +49,7 @@ void r2mcp_help(void) {
 		" -S [url]   enable supervisor control; connect to svc at [url]\n"
 		" -P [dir]   specify custom prompts directory (supports colon-separated paths like r2ai)\n"
 		" -N         do not load any prompts\n"
+		" -L         enable session management tools (list/open/close sessions)\n"
 		" -v         show version\n";
 	printf ("%s", help_text);
 }
@@ -81,10 +82,11 @@ int r2mcp_main(int argc, const char **argv) {
 	char *prompts_dir = NULL;
 	bool load_prompts = true;
 	bool ignore_analysis_level = false;
+	bool use_sessions = false;
 	const char *dsl_tests = NULL;
 	RList *disabled_tools = NULL;
 	RGetopt opt;
-	r_getopt_init (&opt, argc, argv, "hmvpd:nc:u:l:s:rite:D:RT:S:P:N");
+	r_getopt_init (&opt, argc, argv, "hmvpd:nc:u:l:s:rite:D:RT:S:P:NL");
 	int c;
 	while ((c = r_getopt_next (&opt)) != -1) {
 		switch (c) {
@@ -166,6 +168,9 @@ int r2mcp_main(int argc, const char **argv) {
 		case 'N':
 			load_prompts = false;
 			break;
+		case 'L':
+			use_sessions = true;
+			break;
 		default:
 			R_LOG_ERROR ("Invalid flag -%c", c);
 			return 1;
@@ -191,6 +196,7 @@ int r2mcp_main(int argc, const char **argv) {
 		.readonly_mode = readonly_mode,
 		.permissive_tools = permissive,
 		.enable_run_command_tool = enable_run_command_tool,
+		.use_sessions = use_sessions,
 		.http_mode = http_mode,
 		.baseurl = baseurl,
 		.svc_baseurl = svc_baseurl,

src/r2mcp.h

@@ -39,6 +39,8 @@ typedef struct {
 	bool minimode;
 	bool permissive_tools; // allow calling tools not exposed for current mode
 	bool enable_run_command_tool;
+	/* When true, enable session management tools (list/open/close sessions) */
+	bool use_sessions;
 	/* When true operate in read-only mode: only expose non-mutating tools */
 	bool readonly_mode;
 	/* When true, operate in HTTP r2pipe client mode and do NOT use r2 C APIs */

src/tools.c

@@ -74,6 +74,9 @@ static inline ToolMode current_mode(const ServerState *ss) {
 	if (ss->http_mode) {
 		return TOOL_MODE_HTTP;
 	}
+	if (ss->use_sessions) {
+		return TOOL_MODE_SESSIONS;
+	}
 	if (ss->readonly_mode) {
 		return TOOL_MODE_RO;
 	}
@@ -212,6 +215,9 @@ void tools_print_table(const ServerState *ss) {
 		if (t->modes & TOOL_MODE_RO) {
 			modes_buf[p++] = 'R';
 		}
+		if (t->modes & TOOL_MODE_SESSIONS) {
+			modes_buf[p++] = 'S';
+		}
 		if (t->modes & TOOL_MODE_NORMAL) {
 			modes_buf[p++] = 'N';
 		}
@@ -792,6 +798,9 @@ static char *tool_run_javascript(ServerState *ss, RJson *tool_args) {
 }
 
 static char *tool_list_sessions(ServerState *ss, RJson *tool_args) {
+	if (!ss->use_sessions) {
+		return jsonrpc_error_response (-32603, "Start r2mcp with -L to support sessions", NULL, NULL);
+	}
 	(void)tool_args;
 	(void)ss;
 	// r2agent command doesn't require an open file, run it directly
@@ -810,6 +819,9 @@ static char *tool_list_sessions(ServerState *ss, RJson *tool_args) {
 }
 
 static char *tool_open_session(ServerState *ss, RJson *tool_args) {
+	if (!ss->use_sessions) {
+		return jsonrpc_error_response (-32603, "Start r2mcp with -L to support sessions", NULL, NULL);
+	}
 	const char *url;
 	if (!validate_required_string_param (tool_args, "url", &url)) {
 		return jsonrpc_error_missing_param ("url");
@@ -852,6 +864,9 @@ static char *tool_open_session(ServerState *ss, RJson *tool_args) {
 }
 
 static char *tool_close_session(ServerState *ss, RJson *tool_args) {
+	if (!ss->use_sessions) {
+		return jsonrpc_error_response (-32603, "Start r2mcp with -L to support sessions", NULL, NULL);
+	}
 	(void)tool_args;
 
 	if (!ss->http_mode) {
@@ -1048,9 +1063,9 @@ ToolSpec tool_specs[] = {
 	{ "open_file", "Opens a binary file with radare2 for analysis <think>Call this tool before any other one from r2mcp. Use an absolute file_path</think>", "{\"type\":\"object\",\"properties\":{\"file_path\":{\"type\":\"string\",\"description\":\"Path to the file to open\"}},\"required\":[\"file_path\"]}", TOOL_MODE_NORMAL | TOOL_MODE_MINI, NULL },
 	{ "run_javascript", "Executes JavaScript code using radare2's qjs runtime", "{\"type\":\"object\",\"properties\":{\"script\":{\"type\":\"string\",\"description\":\"The JavaScript code to execute\"}},\"required\":[\"script\"]}", TOOL_MODE_NORMAL | TOOL_MODE_MINI | TOOL_MODE_HTTP, tool_run_javascript },
 	{ "run_command", "Executes a raw radare2 command directly", "{\"type\":\"object\",\"properties\":{\"command\":{\"type\":\"string\",\"description\":\"The radare2 command to execute\"}},\"required\":[\"command\"]}", TOOL_MODE_NORMAL | TOOL_MODE_MINI | TOOL_MODE_HTTP, tool_run_command },
-	{ "list_sessions", "Lists available r2agent sessions in JSON format", "{\"type\":\"object\",\"properties\":{}}", TOOL_MODE_NORMAL | TOOL_MODE_HTTP | TOOL_MODE_RO, tool_list_sessions },
-	{ "open_session", "Connects to a remote r2 instance using r2pipe API", "{\"type\":\"object\",\"properties\":{\"url\":{\"type\":\"string\",\"description\":\"URL of the remote r2 instance to connect to\"}},\"required\":[\"url\"]}", TOOL_MODE_NORMAL | TOOL_MODE_HTTP, tool_open_session },
-	{ "close_session", "Close the currently open remote session", "{\"type\":\"object\",\"properties\":{}}", TOOL_MODE_NORMAL | TOOL_MODE_HTTP, tool_close_session },
+	{ "list_sessions", "Lists available r2agent sessions in JSON format", "{\"type\":\"object\",\"properties\":{}}", TOOL_MODE_NORMAL | TOOL_MODE_HTTP | TOOL_MODE_RO | TOOL_MODE_SESSIONS, tool_list_sessions },
+	{ "open_session", "Connects to a remote r2 instance using r2pipe API", "{\"type\":\"object\",\"properties\":{\"url\":{\"type\":\"string\",\"description\":\"URL of the remote r2 instance to connect to\"}},\"required\":[\"url\"]}", TOOL_MODE_NORMAL | TOOL_MODE_HTTP | TOOL_MODE_SESSIONS , tool_open_session },
+	{ "close_session", "Close the currently open remote session", "{\"type\":\"object\",\"properties\":{}}", TOOL_MODE_NORMAL | TOOL_MODE_HTTP | TOOL_MODE_SESSIONS, tool_close_session },
 	{ "close_file", "Close the currently open file", "{\"type\":\"object\",\"properties\":{}}", TOOL_MODE_NORMAL, tool_close_file },
 	{ "list_functions", "Lists all functions discovered during analysis", "{\"type\":\"object\",\"properties\":{\"only_named\":{\"type\":\"boolean\",\"description\":\"If true, only list functions with named symbols (excludes functions with numeric suffixes like sym.func.1000016c8)\"},\"filter\":{\"type\":\"string\",\"description\":\"Regular expression to filter the results\"}}}", TOOL_MODE_NORMAL | TOOL_MODE_MINI | TOOL_MODE_HTTP | TOOL_MODE_RO, tool_list_functions },
 	{ "list_functions_tree", "Lists functions and successors (aflmu)", "{\"type\":\"object\",\"properties\":{}}", TOOL_MODE_NORMAL | TOOL_MODE_MINI | TOOL_MODE_HTTP | TOOL_MODE_RO, tool_list_functions_tree },

src/tools.h

@@ -8,6 +8,7 @@ typedef enum {
 	TOOL_MODE_HTTP = 1 << 1,
 	TOOL_MODE_NORMAL = 1 << 2,
 	TOOL_MODE_RO = 1 << 3,
+	TOOL_MODE_SESSIONS = 1 << 4,
 } ToolMode;
 
 // Tool handler signature: returns heap-allocated JSON string describing