3 files changed, 40 insertions, 7 deletions

diff --git a/src/nvim/api/keysets.lua b/src/nvim/api/keysets.lua
index 6924e2ef8f..d4882abffe 100644
--- a/src/nvim/api/keysets.lua
+++ b/src/nvim/api/keysets.lua
@@ -85,6 +85,8 @@ return {
   };
   option = {
     "scope";
+    "win";
+    "buf";
   };
   highlight = {
     "bold";
diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index adabb1471e..c251a4a25c 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -1040,8 +1040,8 @@ Object copy_object(Object obj)
   }
 }
 
-static void set_option_value_for(char *key, int numval, char *stringval, int opt_flags,
-                                 int opt_type, void *from, Error *err)
+void set_option_value_for(char *key, long numval, char *stringval, int opt_flags,
+                          int opt_type, void *from, Error *err)
 {
   switchwin_T switchwin;
   aco_save_T aco;
@@ -1081,7 +1081,7 @@ static void set_option_value_for(char *key, int numval, char *stringval, int opt
 }
 
 
-static void set_option_value_err(char *key, int numval, char *stringval, int opt_flags, Error *err)
+static void set_option_value_err(char *key, long numval, char *stringval, int opt_flags, Error *err)
 {
   char *errmsg;
 
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 15992a98be..8e216c2031 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -775,11 +775,15 @@ end:
 /// |:set|: for global-local options, both the global and local value are set
 /// unless otherwise specified with {scope}.
 ///
+/// Note the options {win} and {buf} cannot be used together.
+///
 /// @param name      Option name
 /// @param value     New option value
 /// @param opts      Optional parameters
 ///                  - scope: One of 'global' or 'local'. Analogous to
 ///                  |:setglobal| and |:setlocal|, respectively.
+///                  - win: |window-ID|. Used for setting window local option.
+///                  - buf: Buffer number. Used for setting buffer local option.
 /// @param[out] err  Error details, if any
 void nvim_set_option_value(String name, Object value, Dict(option) *opts, Error *err)
   FUNC_API_SINCE(9)
@@ -799,6 +803,36 @@ void nvim_set_option_value(String name, Object value, Dict(option) *opts, Error
     return;
   }
 
+  int opt_type = SREQ_GLOBAL;
+  void *to = NULL;
+
+  if (opts->win.type == kObjectTypeInteger) {
+    opt_type = SREQ_WIN;
+    to = find_window_by_handle((int)opts->win.data.integer, err);
+  } else if (HAS_KEY(opts->win)) {
+    api_set_error(err, kErrorTypeValidation, "invalid value for key: win");
+    return;
+  }
+
+  if (opts->buf.type == kObjectTypeInteger) {
+    scope = OPT_LOCAL;
+    opt_type = SREQ_BUF;
+    to = find_buffer_by_handle((int)opts->buf.data.integer, err);
+  } else if (HAS_KEY(opts->buf)) {
+    api_set_error(err, kErrorTypeValidation, "invalid value for key: buf");
+    return;
+  }
+
+  if (HAS_KEY(opts->scope) && HAS_KEY(opts->buf)) {
+    api_set_error(err, kErrorTypeValidation, "scope and buf cannot be used together");
+    return;
+  }
+
+  if (HAS_KEY(opts->win) && HAS_KEY(opts->buf)) {
+    api_set_error(err, kErrorTypeValidation, "buf and win cannot be used together");
+    return;
+  }
+
   long numval = 0;
   char *stringval = NULL;
 
@@ -820,10 +854,7 @@ void nvim_set_option_value(String name, Object value, Dict(option) *opts, Error
     return;
   }
 
-  char *e = set_option_value(name.data, numval, stringval, scope);
-  if (e) {
-    api_set_error(err, kErrorTypeException, "%s", e);
-  }
+  set_option_value_for(name.data, numval, stringval, scope, opt_type, to, err);
 }
 
 /// Gets the option information for all options.