diff --git a/src/am.lua b/src/am.lua
index 501e4f5..b1952f5 100644
--- a/src/am.lua
+++ b/src/am.lua
@@ -283,8 +283,12 @@ end
 ---@param file string?
 ---@param path string
 ---@param value any
----@param output_format "json"|"hjson"?
-function am.modify_file(mode, file, path, value, output_format)
+---@param content_type "json"|"hjson"?
+function am.modify_file(mode, file, path, value, content_type)
+	if type(content_type) ~= "string" then
+		content_type = "hjson"
+	end
+
 	-- split path by dot
 	local path_parts = {}
 	for part in string.gmatch(path, "[^%.]+") do
@@ -292,13 +296,13 @@ function am.modify_file(mode, file, path, value, output_format)
 	end
 
 	-- try parse value as json/hjson
-	if type(value) == "string" then
+	if table.includes({ "json", "hjson" }, content_type) and type(value) == "string" then
 		local parsed_value, err = hjson.parse(value)
 		ami_assert(err == nil, "failed to parse value: " .. tostring(err), EXIT_MODIFY_ERROR)
 		value = parsed_value
 	end
 
-	local ok, err = ami_util.modify_file(mode, file, path_parts, value, output_format)
+	local ok, err = ami_util.modify_file(mode, file, path_parts, value, content_type)
 	ami_assert(ok, "failed to modify configuration: " .. tostring(err), EXIT_MODIFY_ERROR)
 	log_success"Requested modification applied."
 end
diff --git a/src/ami/internals/interface/app.lua b/src/ami/internals/interface/app.lua
index 3b0d192..e4977c6 100644
--- a/src/ami/internals/interface/app.lua
+++ b/src/ami/internals/interface/app.lua
@@ -43,7 +43,7 @@ local function new(options)
             index = 0,
             description = "ami 'info' sub command",
             summary = implementation_status .. " Prints runtime info and status of the app",
-            action = violation_fallback
+            action = violation_fallback,
         },
         setup = {
             index = 1,
@@ -52,24 +52,24 @@ local function new(options)
             options = {
                 environment = {
                     index = 0,
-                    aliases = {"env"},
-                    description = "Creates application environment"
+                    aliases = { "env" },
+                    description = "Creates application environment",
                 },
                 app = {
                     index = 1,
-                    description = "Generates app folder structure and files"
+                    description = "Generates app folder structure and files",
                 },
                 configure = {
                     index = 2,
-                    description = "Configures application and renders templates"
+                    description = "Configures application and renders templates",
                 },
                 ["no-validate"] = {
                     index = 3,
-                    description = "Disables platform and configuration validation"
-                }
+                    description = "Disables platform and configuration validation",
+                },
             },
             -- (options, command, args, cli)
-            action = function(options)
+            action = function (options)
                 local no_options = #table.keys(options) == 0
 
                 if no_options or options.environment then
@@ -84,9 +84,9 @@ local function new(options)
                 end
 
                 if (no_options or options.configure) and not am.app.__are_templates_generated() then
-					am.app.render()
+                    am.app.render()
                 end
-            end
+            end,
         },
         validate = {
             index = 2,
@@ -95,42 +95,42 @@ local function new(options)
             options = {
                 platform = {
                     index = 1,
-                    description = "Validates application platform"
+                    description = "Validates application platform",
                 },
                 configuration = {
                     index = 2,
-                    description = "Validates application configuration"
-                }
+                    description = "Validates application configuration",
+                },
             },
-            action = violation_fallback
+            action = violation_fallback,
         },
         start = {
             index = 3,
-            aliases = {"s"},
+            aliases = { "s" },
             description = "ami 'start' sub command ",
             summary = implementation_status .. " Starts the app",
             -- (options, command, args, cli)
-            action = violation_fallback
+            action = violation_fallback,
         },
         stop = {
             index = 4,
             description = "ami 'stop' sub command",
             summary = implementation_status .. " Stops the app",
             -- (options, command, args, cli)
-            action = violation_fallback
+            action = violation_fallback,
         },
         update = {
             index = 5,
             description = "ami 'update' command",
             summary = "Updates the app or returns setup required",
             -- (options, command, args, cli)
-            action = function()
+            action = function ()
                 local available, id, ver = am.app.is_update_available()
                 if available then
                     ami_error("Found new version " .. ver .. " of " .. id .. ", please run setup...", EXIT_SETUP_REQUIRED)
                 end
-                log_info("Application is up to date.")
-            end
+                log_info"Application is up to date."
+            end,
         },
         remove = {
             index = 6,
@@ -138,24 +138,26 @@ local function new(options)
             summary = "Remove the app or parts based on options",
             options = {
                 all = {
-                    description = "Removes entire application keeping only app.hjson"
+                    description = "Removes entire application keeping only app.hjson",
+                },
+                force = {
+                    description = "Forces removal of application",
+                    hidden = true,
                 },
-				force = {
-					description = "Forces removal of application",
-					hidden = true,
-				}
             },
             -- (options, command, args, cli)
-            action = function(options)
-				ami_assert(am.__has_app_specific_interface or options.force, "you are trying to remove app, but app specific removal routine is not available. Use '--force' to force removal", EXIT_APP_REMOVE_ERROR)
-				if options.all then
+            action = function (options)
+                ami_assert(am.__has_app_specific_interface or options.force,
+                    "you are trying to remove app, but app specific removal routine is not available. Use '--force' to force removal",
+                    EXIT_APP_REMOVE_ERROR)
+                if options.all then
                     am.app.remove()
-                    log_success("Application removed.")
+                    log_success"Application removed."
                 else
                     am.app.remove_data()
-                    log_success("Application data removed.")
+                    log_success"Application data removed."
                 end
-            end
+            end,
         },
         modify = {
             description = "ami 'modify' sub command",
@@ -164,43 +166,60 @@ local function new(options)
             options = {
                 file = {
                     index = 1,
-                    description = "Path to configuration file to modify (Defaults to app.h/json)"
+                    aliases = { "f" },
+                    description = "Path to configuration file to modify (Defaults to app.h/json)",
                 },
                 set = {
                     description = "Sets value at path",
-                    type = "boolean"
+                    type = "boolean",
                 },
                 unset = {
                     description = "Unsets value at path",
-                    type = "boolean"
+                    type = "boolean",
                 },
                 add = {
                     description = "Adds value to list or dictionary",
-                    type = "boolean"
+                    type = "boolean",
                 },
                 remove = {
                     description = "Removes value from list or dictionary",
-                    type = "boolean"
+                    type = "boolean",
+                },
+                json = {
+                    description = "Forces file to be treated as JSON",
+                    type = "boolean",
+                },
+                hjson = {
+                    description = "Forces file to be treated as HJSON (default)",
+                    type = "boolean",
                 },
-                ["json-output"] = {
-                    description = "Outputs value as JSON (not HJSON)",
-                    type = "boolean"
-                }
             },
             action = function (options, _, args)
-                ami_assert(#args > 1 or (#args == 1 and options.unset), "invalid arguments to modify command - needs path and value or --unset and path", EXIT_MODIFY_ERROR)
-                options.set = options.set or (not options.unset and not options.add and not options.remove) -- default to set
+                ami_assert(#args > 1 or (#args == 1 and options.unset),
+                    "invalid arguments to modify command - needs path and value or --unset and path", EXIT_MODIFY_ERROR)
+                options.set = options.set or
+                   (not options.unset and not options.add and not options.remove) -- default to set
 
-                local options_without_file = table.filter(options, function(key, v) return key ~= "file" and v == true end)
-                ami_assert(#table.keys(options_without_file) <= 1, "only one modification mode can be specified", EXIT_MODIFY_ERROR)
+                local modify_options = table.filter(options, function (key, v)
+                    return v and not table.includes({ "file", "json", "hjson" }, key)
+                end)
+                ami_assert(#table.keys(modify_options) <= 1, "only one modification mode can be specified",
+                    EXIT_MODIFY_ERROR)
                 local mode = "auto"
-                if #table.keys(options_without_file) == 1 then
-                    mode = table.keys(options_without_file)[1]
+                if #table.keys(modify_options) == 1 then
+                    mode = table.keys(modify_options)[1]
                 end
 
-                am.modify_file(mode, options.file, args[1].value, #args > 1 and args[2].value or nil)
-            end
-		},
+                ami_assert(not (options.json and options.hjson),
+                    "only one format flag (--json or --hjson) can be specified", EXIT_MODIFY_ERROR)
+                local content_type = "hjson"
+                if options.json then
+                    content_type = "json"
+                end
+
+                am.modify_file(mode, options.file, args[1].value, #args > 1 and args[2].value or nil, content_type)
+            end,
+        },
         show = {
             description = "ami 'show' sub command",
             summary = "Shows value from app configuration file",
@@ -208,19 +227,19 @@ local function new(options)
             options = {
                 file = {
                     index = 1,
-                    description = "Path to configuration file to show from (Defaults to app.h/json)"
-                }
+                    description = "Path to configuration file to show from (Defaults to app.h/json)",
+                },
             },
             action = function (options, _, args)
                 am.show_file(options.file, type(args) == "table" and #args > 0 and args[1].value or nil)
-            end
+            end,
         },
         about = {
             index = 7,
             description = "ami 'about' sub command",
             summary = implementation_status .. " Prints informations about app",
             -- (options, command, args, cli)
-            action = violation_fallback
+            action = violation_fallback,
         },
         pack = {
             description = "ami 'pack' sub command",
@@ -228,20 +247,20 @@ local function new(options)
             options = {
                 output = {
                     index = 1,
-                    aliases = {"o"},
-                    description = "Output path for the archive"
+                    aliases = { "o" },
+                    description = "Output path for the archive",
                 },
                 light = {
                     index = 2,
-                    description = "If used the archive will not include application data"
-                }
+                    description = "If used the archive will not include application data",
+                },
             },
             action = function (options)
-                am.app.pack({
+                am.app.pack{
                     destination = options.output,
-                    mode = options.light and "light" or "full"
-                })
-            end
+                    mode = options.light and "light" or "full",
+                }
+            end,
         },
         unpack = {
             description = "ami 'unpack' sub command",
@@ -250,19 +269,19 @@ local function new(options)
             options = {
                 source = {
                     index = 1,
-                    description = "Path to the archive"
-                }
+                    description = "Path to the archive",
+                },
             },
             action = function (options)
                 options.__rerun = table.get(options, "__rerun", true)
                 am.app.unpack(options)
-                log_success("application unpacked")
-            end
-        }
+                log_success"application unpacked"
+            end,
+        },
     }
-    return base 
+    return base
 end
 
 return {
-    new = new
+    new = new,
 }
diff --git a/src/ami/internals/util.lua b/src/ami/internals/util.lua
index b4d7d76..d087623 100644
--- a/src/ami/internals/util.lua
+++ b/src/ami/internals/util.lua
@@ -215,22 +215,26 @@ end
 ---@param file string?
 ---@param path string[]
 ---@param value any
----@param output_format "json"|"hjson"?
+---@param content_type "json"|"hjson"?
 ---@return boolean?, string?
-function util.modify_file(mode, file, path, value, output_format)
+function util.modify_file(mode, file, path, value, content_type)
 	if type(mode) ~= "string" then
 		mode = "auto"
 	end
-	if type(output_format) ~= "string" then
-		output_format = "hjson"
+	if type(content_type) ~= "string" then
+		content_type = "hjson"
+	else
+		if not table.includes({ "hjson", "json" }, content_type) then
+			return nil, "content type must be either 'hjson' or 'json'"
+		end
 	end
 	if type(file) ~= "string" then
 		file, _ = find_default_modify_file()
-        if type(file) ~= "string" then return nil, "no valid configuration file found to modify" end
+		if type(file) ~= "string" then return nil, "no valid configuration file found to modify" end
 	end
 
 	local raw_content, err = fs.read_file(file --[[@as string ]])
-    if not raw_content then
+	if not raw_content then
 		if table.includes({ "auto", "set" }, mode) then
 			raw_content = "{}"
 		elseif table.includes({ "add" }, mode) then
@@ -238,11 +242,11 @@ function util.modify_file(mode, file, path, value, output_format)
 		else
 			return nil, err or "failed to read configuration file"
 		end
-	 end
+	end
 	local content, err = hjson.parse(raw_content --[[@as string ]])
-    if not content then return nil, "failed to parse configuration file '" .. tostring(file) .. "': " .. tostring(err) end
+	if not content then return nil, "failed to parse configuration file '" .. tostring(file) .. "': " .. tostring(err) end
 
-    if not modify_handlers[mode] then return nil, "invalid modify mode: " .. tostring(mode) end
+	if not modify_handlers[mode] then return nil, "invalid modify mode: " .. tostring(mode) end
 
 	local default = value
 	if table.includes({"add", "remove"}, mode) then
@@ -251,23 +255,28 @@ function util.modify_file(mode, file, path, value, output_format)
 	local current_value = table.get(content, path, default)
 
 	local new_value, err = modify_handlers[mode](current_value, value)
-    if not new_value and err then return nil, "modification failed: " .. tostring(err) end
+	if not new_value and err then return nil, "modification failed: " .. tostring(err) end
 
 	local result, err = table.set(content, path, new_value)
 	if err == "cannot set nested value on a non-table object" then
 		return nil, "cannot set nested value on a non-table value at path: " .. table.concat(path, ".")
 	end
-    if not result then return nil, "failed to set new value in configuration" end
+	if not result then return nil, "failed to set new value in configuration" end
+
+	local marshallers = {
+		hjson = hjson.stringify,
+		json = hjson.stringify_to_json
+	}
 
-	local marshal_fn = output_format == "json" and hjson.stringify_to_json or hjson.stringify
+	local marshal_fn = marshallers[content_type]
 	local new_raw_content, err = marshal_fn(result, { indent = "\t", sort_keys = true })
-    if not new_raw_content then return nil, "failed to serialize modified configuration: " .. tostring(err) end
+	if not new_raw_content then return nil, "failed to serialize modified configuration: " .. tostring(err) end
 	local ok, err = fs.write_file(file .. ".new" --[[@as string ]], new_raw_content --[[@as string ]])
-    if not ok then return nil, "failed to write modified configuration to file '" .. tostring(file) .. ".new': " .. tostring(err) end
+	if not ok then return nil, "failed to write modified configuration to file '" .. tostring(file) .. ".new': " .. tostring(err) end
 	-- replace original file
 	local ok, err = os.rename(file .. ".new" --[[@as string ]], file --[[@as string ]])
-    if not ok then return nil, "failed to replace original configuration file '" .. tostring(file) .. "': " .. tostring(err) end
-    return true
+	if not ok then return nil, "failed to replace original configuration file '" .. tostring(file) .. "': " .. tostring(err) end
+	return true
 end
 
 ---checks configurations
diff --git a/tests/test/modify_n_show.lua b/tests/test/modify_n_show.lua
index 09fb0d9..f8e02f1 100644
--- a/tests/test/modify_n_show.lua
+++ b/tests/test/modify_n_show.lua
@@ -383,3 +383,58 @@ add_fail_test(test, "syntax and logic errors", {
         expected_error = "unknown option",
     },
 })
+
+-- Test format flags
+test["format flags: json and hjson output"] = function ()
+    local test_dir = "tests/tmp/ami_test_format"
+    fs.mkdirp(test_dir)
+    fs.remove(test_dir, { recurse = true, content_only = true })
+
+    -- Test with --json flag
+    local json_file = path.combine(test_dir, "test.json")
+    fs.write_file(json_file, "{}")
+
+    local args_json = { "--log-level=error", "--path=" .. test_dir, "modify", "--file=test.json", "--json",
+        "test.key", "value123" }
+    local ok, err = pcall(ami, table.unpack(args_json))
+    os.chdir(default_cwd)
+    test.assert(ok, "Failed to modify with --json: " .. tostring(err))
+
+    -- Check that the file is in JSON format (no comments, strict JSON)
+    local json_content = fs.read_file(path.combine(test_dir, "test.json"))
+    test.assert(json_content ~= nil, "Failed to read json file")
+    -- JSON format should not have comments and should use quotes for keys
+    test.assert(json_content:find'"test"' ~= nil, "JSON output should have quoted keys")
+
+    -- Test with --hjson flag (explicit, same as default)
+    local hjson_file = path.combine(test_dir, "test.hjson")
+    fs.write_file(hjson_file, "{}")
+
+    local args_hjson = { "--log-level=error", "--path=" .. test_dir, "modify", "--file=test.hjson", "--hjson",
+        "test.key", "value456" }
+    local ok, err = pcall(ami, table.unpack(args_hjson))
+    os.chdir(default_cwd)
+    test.assert(ok, "Failed to modify with --hjson: " .. tostring(err))
+
+    -- Check that the file is in HJSON format
+    local hjson_content = fs.read_file(path.combine(test_dir, "test.hjson"))
+    test.assert(hjson_content ~= nil, "Failed to read hjson file")
+
+    -- Test that using both --json and --hjson fails
+    local both_file = path.combine(test_dir, "test_both.hjson")
+    fs.write_file(both_file, "{}")
+
+    local args_both = { "--log-level=error", "--path=" .. test_dir, "modify", "--file=test_both.hjson",
+        "--json", "--hjson", "test.key", "value789" }
+    local ok, err = pcall(ami, table.unpack(args_both))
+    os.chdir(default_cwd)
+    test.assert(not ok, "Should fail when both --json and --hjson are specified")
+    test.assert(tostring(err):find"only one format flag" ~= nil,
+        "Error message should mention only one format flag can be specified")
+
+    os.chdir(default_cwd)
+end
+
+if not TEST then
+    test.summary()
+end