diff --git a/src/windy/platforms/emscripten/emdefs.nim b/src/windy/platforms/emscripten/emdefs.nim
index 0fa2987..f2e0b1e 100644
--- a/src/windy/platforms/emscripten/emdefs.nim
+++ b/src/windy/platforms/emscripten/emdefs.nim
@@ -158,6 +158,29 @@ EM_JS(void, set_cursor, (const char* cursor), {
   const cursorUtf8 = UTF8ToString(cursor);
   Module.canvas.style.cursor = cursorUtf8;
 });
+
+EM_JS(int, get_local_storage_length, (const char* key), {
+  const keyUtf8 = UTF8ToString(key);
+  const value = localStorage.getItem(keyUtf8);
+  if (value === null) return 1; // Only null terminator if not found
+  return lengthBytesUTF8(value) + 1; // Include null terminator
+});
+
+EM_JS(int, get_local_storage_into, (char* output, int maxLen, const char* key), {
+  const keyUtf8 = UTF8ToString(key);
+  const value = localStorage.getItem(keyUtf8);
+  if (value === null) {
+    if (maxLen > 0) output[0] = 0; // Null terminator only
+    return 1;
+  }
+  return stringToUTF8(value, output, maxLen);
+});
+
+EM_JS(void, set_local_storage, (const char* key, const char* value), {
+  const keyUtf8 = UTF8ToString(key);
+  const valueUtf8 = UTF8ToString(value);
+  localStorage.setItem(keyUtf8, valueUtf8);
+});
 """.}
 
 proc get_window_width*(): cint {.importc.}
@@ -175,6 +198,9 @@ proc open_temp_text_file*(title, text: cstring) {.importc.}
 proc open_url*(url: cstring) {.importc.}
 proc setup_drag_drop_handlers_internal*(target: cstring, userData: pointer) {.importc.}
 proc set_cursor*(cursor: cstring) {.importc.}
+proc getLocalStorageLength*(key: cstring): cint {.importc: "get_local_storage_length".}
+proc getLocalStorageInto*(output: cstring, maxLen: cint, key: cstring): cint {.importc: "get_local_storage_into".}
+proc setLocalStorage*(key: cstring, value: cstring) {.importc: "set_local_storage".}
 
 type
   EMSCRIPTEN_RESULT* = cint
diff --git a/src/windy/platforms/emscripten/platform.nim b/src/windy/platforms/emscripten/platform.nim
index 62b9d2f..51d877e 100644
--- a/src/windy/platforms/emscripten/platform.nim
+++ b/src/windy/platforms/emscripten/platform.nim
@@ -788,6 +788,25 @@ proc `onDownloadProgress=`*(handle: HttpRequestHandle, callback: HttpProgressCal
   if state == nil: return
   state.onDownloadProgress = callback
 
+proc getConfigHome*(appName: string): string =
+  raise newException(Exception, "getConfigHome is not supported on emscripten")
+
+proc getConfig*(appName: string, fileName: string): string =
+  ## Returns the contents of a config file for the given app and filename from localStorage.
+  ## Returns empty string if the config doesn't exist.
+  let key = appName & ":" & fileName
+  let length = getLocalStorageLength(key.cstring)
+  if length <= 1: # Only null terminator means no content
+    return ""
+  var buffer = newString(length - 1) # -1 for null terminator
+  discard getLocalStorageInto(buffer.cstring, length.cint, key.cstring)
+  result = buffer
+
+proc setConfig*(appName: string, fileName: string, content: string) =
+  ## Saves content to a config file for the given app and filename in localStorage.
+  let key = appName & ":" & fileName
+  setLocalStorage(key.cstring, content.cstring)
+
 proc openTempTextFile*(title, text: string) =
   ## Open a new tab in the browser.
   open_temp_text_file(title.cstring, text.cstring)
diff --git a/src/windy/platforms/linux/x11.nim b/src/windy/platforms/linux/x11.nim
index 56c812b..a7e19a1 100644
--- a/src/windy/platforms/linux/x11.nim
+++ b/src/windy/platforms/linux/x11.nim
@@ -1,5 +1,5 @@
 import
-  std/[os, sequtils, sets, strformat, strutils, times, unicode, uri],
+  std/[os, sequtils, sets, strformat, strutils, times, unicode, uri, pathnorm],
   ../../[common, internal],
   vmath, pixie,
   x11/[glx, keysym, x, xevent, xlib, xcursor]
@@ -1327,6 +1327,34 @@ proc url*(window: Window): string =
   ## Url cannot be gotten on linux.
   warn "Url cannot be gotten on linux"
 
+proc getConfigHome*(appName: string): string =
+  ## Returns the platform-appropriate user config directory for the given app name.
+  ## For Linux: Honors XDG_CONFIG_HOME, defaults to ~/.config/<appName>.
+  let xdgConfigHome = getEnv("XDG_CONFIG_HOME")
+  if xdgConfigHome != "":
+    result = (xdgConfigHome / appName).normalizePath
+  else:
+    result = (getHomeDir() / ".config" / appName).normalizePath
+
+proc getConfig*(appName: string, fileName: string): string =
+  ## Returns the contents of a config file for the given app and filename.
+  ## Returns empty string if the file doesn't exist.
+  let configDir = getConfigHome(appName)
+  let configPath = configDir / fileName
+  if fileExists(configPath):
+    result = readFile(configPath)
+  else:
+    result = ""
+
+proc setConfig*(appName: string, fileName: string, content: string) =
+  ## Saves content to a config file for the given app and filename.
+  ## Creates the config directory if it doesn't exist.
+  let configDir = getConfigHome(appName)
+  if not dirExists(configDir):
+    createDir(configDir)
+  let configPath = configDir / fileName
+  writeFile(configPath, content)
+
 proc openUrl*(url: string) =
   ## Open a URL in the default browser.
   discard execShellCmd("xdg-open " & url)
diff --git a/src/windy/platforms/macos/platform.nim b/src/windy/platforms/macos/platform.nim
index 6081c3c..1b1557e 100644
--- a/src/windy/platforms/macos/platform.nim
+++ b/src/windy/platforms/macos/platform.nim
@@ -1,5 +1,5 @@
 import
-  std/[os, times, unicode],
+  std/[os, times, unicode, pathnorm],
   opengl, pixie/fileformats/png, pixie/images, utils, vmath,
   ../../[common, internal], macdefs
 
@@ -1094,6 +1094,30 @@ proc getScreens*(): seq[Screen] =
         primary: i == 0
       )
 
+proc getConfigHome*(appName: string): string =
+  ## Returns the platform-appropriate user config directory for the given app name.
+  ## For macOS: Returns ~/Library/Application Support/<appName>.
+  result = (getHomeDir() / "Library" / "Application Support" / appName).normalizePath
+
+proc getConfig*(appName: string, fileName: string): string =
+  ## Returns the contents of a config file for the given app and filename.
+  ## Returns empty string if the file doesn't exist.
+  let configDir = getConfigHome(appName)
+  let configPath = configDir / fileName
+  if fileExists(configPath):
+    result = readFile(configPath)
+  else:
+    result = ""
+
+proc setConfig*(appName: string, fileName: string, content: string) =
+  ## Saves content to a config file for the given app and filename.
+  ## Creates the config directory if it doesn't exist.
+  let configDir = getConfigHome(appName)
+  if not dirExists(configDir):
+    createDir(configDir)
+  let configPath = configDir / fileName
+  writeFile(configPath, content)
+
 proc openTempTextFile*(title, text: string) =
   ## Open a text file in the default text editor.
   if not dirExists("tmp"):
diff --git a/src/windy/platforms/win32/platform.nim b/src/windy/platforms/win32/platform.nim
index 37582c2..16029b3 100644
--- a/src/windy/platforms/win32/platform.nim
+++ b/src/windy/platforms/win32/platform.nim
@@ -1,5 +1,5 @@
 import
-  std/[os, times, unicode, strutils, tables],
+  std/[os, times, unicode, strutils, tables, pathnorm],
   ../../[common, internal], flatty/binny, pixie/fileformats/png,
   pixie/fileformats/bmp, pixie/images,
   urlly, utils, vmath, windefs, zippy
@@ -2492,6 +2492,30 @@ proc forceButtonReleased*(window: Window, button: Button) =
   ## This is used for simulating UI tests.
   window.handleButtonRelease(button)
 
+proc getConfigHome*(appName: string): string =
+  ## Returns the platform-appropriate user config directory for the given app name.
+  ## For Windows: Returns %APPDATA%\<appName>.
+  result = (getEnv("APPDATA") / appName).normalizePath
+
+proc getConfig*(appName: string, fileName: string): string =
+  ## Returns the contents of a config file for the given app and filename.
+  ## Returns empty string if the file doesn't exist.
+  let configDir = getConfigHome(appName)
+  let configPath = configDir / fileName
+  if fileExists(configPath):
+    result = readFile(configPath)
+  else:
+    result = ""
+
+proc setConfig*(appName: string, fileName: string, content: string) =
+  ## Saves content to a config file for the given app and filename.
+  ## Creates the config directory if it doesn't exist.
+  let configDir = getConfigHome(appName)
+  if not dirExists(configDir):
+    createDir(configDir)
+  let configPath = configDir / fileName
+  writeFile(configPath, content)
+
 proc openTempTextFile*(title, text: string) =
   ## Open a text file in the default text editor.
   if not dirExists("tmp"):