diff --git a/src/main.zig b/src/main.zig
index 541ba53..a2716d7 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -16,12 +16,26 @@ const readline = @cImport({
     @cInclude("readline/history.h");
 });
 
-fn wrapInCmdList(allocator: *std.mem.Allocator, cmd: langs.Command) !langs.CommandList {
+fn wrapInCmdList(allocator: *std.mem.Allocator, cmd: *langs.Command) !langs.CommandList {
     var cmds = langs.CommandList.init(allocator);
     try cmds.append(cmd);
     return cmds;
 }
 
+fn copyCommandToHeap(allocator: *std.mem.Allocator, command: langs.Command, comptime tag: langs.Command.Tag) !*langs.Command {
+    const CommandStruct = langs.Command.tagToType(tag);
+    const casted = command.cast(CommandStruct).?;
+    var heap_cmd = try allocator.create(CommandStruct);
+
+    @memcpy(
+        @ptrCast([*]u8, &heap_cmd),
+        @ptrCast([*]const u8, &casted),
+        @sizeOf(CommandStruct),
+    );
+
+    return &heap_cmd.base;
+}
+
 pub fn doRepl(allocator: *std.mem.Allocator, args_it: var) !void {
     var stdout_file = std.io.getStdOut();
     const stdout = &stdout_file.outStream();
@@ -104,11 +118,12 @@ pub fn doRepl(allocator: *std.mem.Allocator, args_it: var) !void {
     // run the load command
     try runner.runCommands(cmds, true);
 
-    var runqs_args = langs.ArgList.init(allocator);
-    defer runqs_args.deinit();
-
     const wanted_runner: []const u8 = std.os.getenv("SCRITCHER_RUNNER") orelse "ristretto";
-    try runqs_args.append(wanted_runner);
+
+    var runqs_cmd = langs.Command.RunQS{
+        .base = langs.Command{ .tag = langs.Command.Tag.runqs },
+        .program = wanted_runner,
+    };
 
     while (true) {
         lang.reset();
@@ -124,11 +139,51 @@ pub fn doRepl(allocator: *std.mem.Allocator, args_it: var) !void {
         var line = rd_line[0..std.mem.len(rd_line)];
 
         if (std.mem.eql(u8, line, "push")) {
-            try cmds.append(current);
+            const heap_cmd = switch (current.tag) {
+                .noop => try copyCommandToHeap(allocator, current, .noop),
+                .load => try copyCommandToHeap(allocator, current, .load),
+                .quicksave => try copyCommandToHeap(allocator, current, .quicksave),
+                .runqs => try copyCommandToHeap(allocator, current, .runqs),
+                .amp => try copyCommandToHeap(allocator, current, .amp),
+                .rflanger => try copyCommandToHeap(allocator, current, .rflanger),
+                .eq => try copyCommandToHeap(allocator, current, .eq),
+                .phaser => try copyCommandToHeap(allocator, current, .phaser),
+                .mbeq => try copyCommandToHeap(allocator, current, .mbeq),
+                .chorus => try copyCommandToHeap(allocator, current, .chorus),
+                .pitchscaler => try copyCommandToHeap(allocator, current, .pitchscaler),
+                .reverb => try copyCommandToHeap(allocator, current, .reverb),
+                .highpass => try copyCommandToHeap(allocator, current, .highpass),
+                .delay => try copyCommandToHeap(allocator, current, .delay),
+                .vinyl => try copyCommandToHeap(allocator, current, .vinyl),
+                .revdelay => try copyCommandToHeap(allocator, current, .revdelay),
+                .gate => try copyCommandToHeap(allocator, current, .gate),
+                .detune => try copyCommandToHeap(allocator, current, .detune),
+                .overdrive => try copyCommandToHeap(allocator, current, .overdrive),
+                .degrade => try copyCommandToHeap(allocator, current, .degrade),
+                .repsycho => try copyCommandToHeap(allocator, current, .repsycho),
+                .talkbox => try copyCommandToHeap(allocator, current, .talkbox),
+                .dyncomp => try copyCommandToHeap(allocator, current, .dyncomp),
+                .thruzero => try copyCommandToHeap(allocator, current, .thruzero),
+                .foverdrive => try copyCommandToHeap(allocator, current, .foverdrive),
+                .gverb => try copyCommandToHeap(allocator, current, .gverb),
+                .invert => try copyCommandToHeap(allocator, current, .invert),
+                .tapedelay => try copyCommandToHeap(allocator, current, .tapedelay),
+                .moddelay => try copyCommandToHeap(allocator, current, .moddelay),
+                .multichorus => try copyCommandToHeap(allocator, current, .multichorus),
+                .saturator => try copyCommandToHeap(allocator, current, .saturator),
+                .vintagedelay => try copyCommandToHeap(allocator, current, .vintagedelay),
+                .noise => try copyCommandToHeap(allocator, current, .noise),
+                .wildnoise => try copyCommandToHeap(allocator, current, .wildnoise),
+                .write => try copyCommandToHeap(allocator, current, .write),
+                .embed => try copyCommandToHeap(allocator, current, .embed),
+                .rotate => try copyCommandToHeap(allocator, current, .rotate),
+            };
+
+            try cmds.append(heap_cmd);
 
             // run the current added command to main cmds list
             // with the main parent runner
-            var cmds_wrapped = try wrapInCmdList(allocator, current);
+            var cmds_wrapped = try wrapInCmdList(allocator, heap_cmd);
             defer cmds_wrapped.deinit();
             try runner.runCommands(cmds_wrapped, true);
 
@@ -153,7 +208,7 @@ pub fn doRepl(allocator: *std.mem.Allocator, args_it: var) !void {
             std.debug.warn("repl: error while parsing: {}\n", .{err});
             continue;
         };
-        current = cmds_parsed.items[0];
+        current = cmds_parsed.items[0].*;
 
         // by cloning the parent runner, we can iteratively write
         // whatever command we want and only commit the good results
@@ -161,10 +216,9 @@ pub fn doRepl(allocator: *std.mem.Allocator, args_it: var) !void {
         var runner_clone = try runner.clone();
         defer runner_clone.deinit();
 
-        try cmds_parsed.append(langs.Command{
-            .command = .RunQS,
-            .args = runqs_args,
-        });
+        // taking address is fine, because runqs_cmd lives in the lifetime
+        // of this function.
+        try cmds.append(&runqs_cmd.base);
 
         try runner_clone.runCommands(cmds_parsed, true);
         _ = try stdout.write("\n");