diff --git a/gen-go-code.py b/gen-go-code.py
index a0bcd3971..54ab4507a 100755
--- a/gen-go-code.py
+++ b/gen-go-code.py
@@ -49,7 +49,7 @@ def replace(template: str, **kw: str) -> str:
 
 json_field_types: Dict[str, str] = {
     'bool': 'bool', 'str': 'string', 'list.str': '[]string', 'dict.str': 'map[string]string', 'float': 'float64', 'int': 'int',
-    'scroll_amount': '[2]interface{}', 'spacing': 'interface{}', 'colors': 'interface{}',
+    'scroll_amount': 'interface{}', 'spacing': 'interface{}', 'colors': 'interface{}',
 }
 
 
@@ -124,10 +124,7 @@ def build_go_code(name: str, cmd: RemoteCommand, seq: OptionSpecSeq, template: s
         jd.append(f.go_declaration())
     jc: List[str] = []
     handled_fields: Set[str] = set()
-    try:
-        jc.extend(cmd.args.as_go_code(name, field_types, handled_fields))
-    except TypeError:
-        print(f'Cant parse args for cmd: {name}', file=sys.stderr)
+    jc.extend(cmd.args.as_go_code(name, field_types, handled_fields))
 
     for field in json_fields:
         if field.field in option_map:
@@ -137,7 +134,6 @@ def build_go_code(name: str, cmd: RemoteCommand, seq: OptionSpecSeq, template: s
             pass
         else:
             print(f'Cant map field: {field.field} for cmd: {name}', file=sys.stderr)
-    print('TODO: test set_window_logo, set_window_background, set_font_size, send_text, env, scroll_window', file=sys.stderr)
 
     argspec = cmd.args.spec
     if argspec:
@@ -232,6 +228,7 @@ def update_at_commands() -> None:
             os.remove(dest)
         with open(dest, 'w') as f:
             f.write(code)
+    print('TODO: test set_window_logo, set_window_background, set_font_size, send_text, env, scroll_window', file=sys.stderr)
 
 
 def main() -> None:
diff --git a/kitty/rc/base.py b/kitty/rc/base.py
index 5cadd0752..d1df3a29a 100644
--- a/kitty/rc/base.py
+++ b/kitty/rc/base.py
@@ -193,12 +193,13 @@ class ArgsHandling:
                 yield f'args = append(args, "{x}")'
             yield '}'
         if self.minimum_count > -1:
-            yield f'if len(args) < {self.minimum_count} {{ return fmt.Errorf("%s", Must specify at least {self.minimum_count} arguments to {cmd_name}) }}'
+            yield f'if len(args) < {self.minimum_count} {{ return fmt.Errorf("%s", "Must specify at least {self.minimum_count} arguments to {cmd_name}") }}'
         if self.args_choices:
             achoices = tuple(self.args_choices())
             yield 'achoices := map[string]bool{' + ' '.join(f'"{x}":true,' for x in achoices) + '}'
             yield 'for _, a := range args {'
             yield 'if !achoices[a] { return fmt.Errorf("Not a valid choice: %s. Allowed values are: %s", a, "' + ', '.join(achoices) + '") }'
+            yield '}'
         if self.json_field:
             jf = self.json_field
             dest = f'payload.{jf.capitalize()}'
@@ -240,6 +241,7 @@ class ArgsHandling:
                 return
             if jt == 'dict.str':
                 yield f'{dest} = parse_key_val_args(args)'
+                return
         raise TypeError(f'Unknown args handling for cmd: {cmd_name}')
 
 
diff --git a/kitty/rc/set_background_image.py b/kitty/rc/set_background_image.py
index e91af9932..fda1b095b 100644
--- a/kitty/rc/set_background_image.py
+++ b/kitty/rc/set_background_image.py
@@ -63,7 +63,7 @@ default=false
 Don't wait for a response from kitty. This means that even if setting the background image
 failed, the command will exit with a success code.
 ''' + '\n\n' + MATCH_WINDOW_OPTION
-    args = RemoteCommand.Args(spec='PATH_TO_PNG_IMAGE', count=1, special_parse='!read_window_logo(args[0])', completion={
+    args = RemoteCommand.Args(spec='PATH_TO_PNG_IMAGE', count=1, json_field='data', special_parse='!read_window_logo(args[0])', completion={
         'files': ('PNG Images', ('*.png',))})
     images_in_flight: Dict[str, IO[bytes]] = {}
     is_asynchronous = True
diff --git a/kitty/rc/set_background_opacity.py b/kitty/rc/set_background_opacity.py
index dfabf9f4d..e00968ef7 100644
--- a/kitty/rc/set_background_opacity.py
+++ b/kitty/rc/set_background_opacity.py
@@ -37,7 +37,7 @@ By default, background opacity are only changed for the currently active window.
 cause background opacity to be changed in all windows.
 
 ''' + '\n\n' + MATCH_WINDOW_OPTION + '\n\n' + MATCH_TAB_OPTION.replace('--match -m', '--match-tab -t')
-    args = RemoteCommand.Args(spec='OPACITY', count=1, json_field='opacity')
+    args = RemoteCommand.Args(spec='OPACITY', count=1, json_field='opacity', special_parse='parse_opacity(args[0])')
 
     def message_to_kitty(self, global_opts: RCOptions, opts: 'CLIOptions', args: ArgsType) -> PayloadType:
         opacity = max(0.1, min(float(args[0]), 1.0))
diff --git a/tools/cmd/at/main.go b/tools/cmd/at/main.go
index 6e46e4ba4..8c9fa3371 100644
--- a/tools/cmd/at/main.go
+++ b/tools/cmd/at/main.go
@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"strconv"
 	"strings"
 	"time"
 
diff --git a/tools/cmd/at/scroll_window.go b/tools/cmd/at/scroll_window.go
index 008be3759..d70a44052 100644
--- a/tools/cmd/at/scroll_window.go
+++ b/tools/cmd/at/scroll_window.go
@@ -8,8 +8,8 @@ import (
 	"strings"
 )
 
-func parse_scroll_amount(amt string) ([2]interface{}, error) {
-	var ans [2]interface{}
+func parse_scroll_amount(amt string) ([]interface{}, error) {
+	var ans = make([]interface{}, 2)
 	if amt == "start" || amt == "end" {
 		ans[0] = amt
 		ans[1] = nil
diff --git a/tools/cmd/at/set_background_opacity.go b/tools/cmd/at/set_background_opacity.go
new file mode 100644
index 000000000..039b49a6e
--- /dev/null
+++ b/tools/cmd/at/set_background_opacity.go
@@ -0,0 +1,19 @@
+// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package at
+
+import "strconv"
+
+func parse_opacity(arg string) (float64, error) {
+	ans, err := strconv.ParseFloat(arg, 64)
+	if err != nil {
+		return 0, nil
+	}
+	if ans < 0.1 {
+		ans = 0.1
+	}
+	if ans > 1 {
+		ans = 1
+	}
+	return ans, nil
+}