diff --git a/bin/main.ml b/bin/main.ml
index e56a02d..57b4bf6 100644
--- a/bin/main.ml
+++ b/bin/main.ml
@@ -56,6 +56,7 @@ Usage:
       List indexed commands.
   inshellah manpage FILE            Parse a manpage and emit nushell extern
   inshellah manpage-dir DIR         Batch-process manpages under DIR
+  inshellah completions             Generate nushell completions for inshellah
 
 |};
   exit 1
@@ -1167,6 +1168,86 @@ let parse_dir_args args =
       | first :: rest -> (first, rest) in
   (user_dir, system_dirs, List.rev rest_args)
 
+(* "inshellah completions nushell" — emit native nushell extern for inshellah itself *)
+let cmd_completions_nushell () =
+  let result = {
+    entries = [];
+    subcommands = [];
+    positionals = [];
+    description = "nushell completions engine";
+  } in
+  let index_result = {
+    entries = [
+      { switch = Long "dir"; param = Some (Mandatory "PATH"); desc = "output directory for cached completions" };
+      { switch = Long "ignore"; param = Some (Mandatory "FILE"); desc = "skip listed commands entirely" };
+      { switch = Long "help-only"; param = Some (Mandatory "FILE"); desc = "skip manpages for listed commands, use --help instead" };
+    ];
+    subcommands = [];
+    positionals = [
+      { pos_name = "prefix"; optional = false; variadic = true };
+    ];
+    description = "index completions from prefix directories";
+  } in
+  let complete_result = {
+    entries = [
+      { switch = Long "dir"; param = Some (Mandatory "PATH"); desc = "colon-separated cache paths" };
+    ];
+    subcommands = [];
+    positionals = [
+      { pos_name = "cmd"; optional = false; variadic = false };
+      { pos_name = "args"; optional = true; variadic = true };
+    ];
+    description = "nushell custom completer, outputs JSON candidates";
+  } in
+  let query_result = {
+    entries = [
+      { switch = Long "dir"; param = Some (Mandatory "PATH"); desc = "colon-separated cache paths" };
+    ];
+    subcommands = [];
+    positionals = [
+      { pos_name = "cmd"; optional = false; variadic = false };
+    ];
+    description = "print stored completion data for a command";
+  } in
+  let dump_result = {
+    entries = [
+      { switch = Long "dir"; param = Some (Mandatory "PATH"); desc = "colon-separated cache paths" };
+    ];
+    subcommands = [];
+    positionals = [];
+    description = "list indexed commands";
+  } in
+  let manpage_result = {
+    entries = [];
+    subcommands = [];
+    positionals = [
+      { pos_name = "file"; optional = false; variadic = false };
+    ];
+    description = "parse a manpage and emit nushell extern";
+  } in
+  let manpage_dir_result = {
+    entries = [];
+    subcommands = [];
+    positionals = [
+      { pos_name = "dir"; optional = false; variadic = false };
+    ];
+    description = "batch-process manpages under a directory";
+  } in
+  let completions_result = {
+    entries = [];
+    subcommands = [];
+    positionals = [];
+    description = "generate nushell completions for inshellah";
+  } in
+  print_string (generate_extern "inshellah" result);
+  print_string (generate_extern "inshellah index" index_result);
+  print_string (generate_extern "inshellah complete" complete_result);
+  print_string (generate_extern "inshellah query" query_result);
+  print_string (generate_extern "inshellah dump" dump_result);
+  print_string (generate_extern "inshellah manpage" manpage_result);
+  print_string (generate_extern "inshellah manpage-dir" manpage_dir_result);
+  print_string (generate_extern "inshellah completions" completions_result)
+
 (* --- entry point ---
  * dispatch on the first argument to the appropriate subcommand handler. *)
 let () =
@@ -1193,4 +1274,5 @@ let () =
     cmd_dump (user_dir :: system_dirs)
   | ["manpage"; file] -> cmd_manpage file
   | ["manpage-dir"; dir] -> cmd_manpage_dir dir
+  | ["completions"] -> cmd_completions_nushell ()
   | _ -> usage ()