diff --git a/Package.swift b/Package.swift
index a0cde7e..94e227f 100644
--- a/Package.swift
+++ b/Package.swift
@@ -55,6 +55,10 @@ let package = Package(
             name: "SVG",
             targets: ["SVG"]
         ),
+        .library(
+            name: "FileSystem",
+            targets: ["FileSystem"]
+        ),
         .executable(name: "WebIDLToSwift", targets: ["WebIDLToSwift"]),
     ],
     dependencies: [
@@ -112,6 +116,10 @@ let package = Package(
             name: "SVG",
             dependencies: ["DOM", "WebAPIBase", "ECMAScript"]
         ),
+        .target(
+            name: "FileSystem",
+            dependencies: ["DOM", "WebAPIBase", "ECMAScript"]
+        ),
         // This support library should be moved to JavaScriptKit
         .target(name: "ECMAScript", dependencies: [
             "JavaScriptKit",
diff --git a/Sources/FileSystem/Generated.swift b/Sources/FileSystem/Generated.swift
new file mode 100644
index 0000000..482ad78
--- /dev/null
+++ b/Sources/FileSystem/Generated.swift
@@ -0,0 +1,875 @@
+// This file was auto-generated by WebIDLToSwift. DO NOT EDIT!
+
+import DOM
+import ECMAScript
+import JavaScriptBigIntSupport
+import JavaScriptEventLoop
+import JavaScriptKit
+import WebAPIBase
+
+public class DirectoryPickerOptions: BridgedDictionary {
+    public convenience init(id: String, startIn: StartInDirectory, mode: FileSystemPermissionMode) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.id] = _toJSValue(id)
+        object[Strings.startIn] = _toJSValue(startIn)
+        object[Strings.mode] = _toJSValue(mode)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _id = ReadWriteAttribute(jsObject: object, name: Strings.id)
+        _startIn = ReadWriteAttribute(jsObject: object, name: Strings.startIn)
+        _mode = ReadWriteAttribute(jsObject: object, name: Strings.mode)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var id: String
+
+    @ReadWriteAttribute
+    public var startIn: StartInDirectory
+
+    @ReadWriteAttribute
+    public var mode: FileSystemPermissionMode
+}
+
+public class FilePickerAcceptType: BridgedDictionary {
+    public convenience init(description: String, accept: [String: String_or_seq_of_String]) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.description] = _toJSValue(description)
+        object[Strings.accept] = _toJSValue(accept)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _description = ReadWriteAttribute(jsObject: object, name: Strings.description)
+        _accept = ReadWriteAttribute(jsObject: object, name: Strings.accept)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var description: String
+
+    @ReadWriteAttribute
+    public var accept: [String: String_or_seq_of_String]
+}
+
+public class FilePickerOptions: BridgedDictionary {
+    public convenience init(types: [FilePickerAcceptType], excludeAcceptAllOption: Bool, id: String, startIn: StartInDirectory) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.types] = _toJSValue(types)
+        object[Strings.excludeAcceptAllOption] = _toJSValue(excludeAcceptAllOption)
+        object[Strings.id] = _toJSValue(id)
+        object[Strings.startIn] = _toJSValue(startIn)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _types = ReadWriteAttribute(jsObject: object, name: Strings.types)
+        _excludeAcceptAllOption = ReadWriteAttribute(jsObject: object, name: Strings.excludeAcceptAllOption)
+        _id = ReadWriteAttribute(jsObject: object, name: Strings.id)
+        _startIn = ReadWriteAttribute(jsObject: object, name: Strings.startIn)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var types: [FilePickerAcceptType]
+
+    @ReadWriteAttribute
+    public var excludeAcceptAllOption: Bool
+
+    @ReadWriteAttribute
+    public var id: String
+
+    @ReadWriteAttribute
+    public var startIn: StartInDirectory
+}
+
+public class FileSystemCreateWritableOptions: BridgedDictionary {
+    public convenience init(keepExistingData: Bool) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.keepExistingData] = _toJSValue(keepExistingData)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _keepExistingData = ReadWriteAttribute(jsObject: object, name: Strings.keepExistingData)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var keepExistingData: Bool
+}
+
+public class FileSystemDirectoryHandle: FileSystemHandle, AsyncSequence {
+    @inlinable override public class var constructor: JSFunction? { JSObject.global[Strings.FileSystemDirectoryHandle].function }
+
+    public required init(unsafelyWrapping jsObject: JSObject) {
+        super.init(unsafelyWrapping: jsObject)
+    }
+
+    public typealias Element = String
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    public func makeAsyncIterator() -> ValueIterableAsyncIterator<FileSystemDirectoryHandle> {
+        ValueIterableAsyncIterator(sequence: self)
+    }
+
+    @inlinable public func getFileHandle(name: String, options: FileSystemGetFileOptions? = nil) -> JSPromise {
+        let this = jsObject
+        return this[Strings.getFileHandle].function!(this: this, arguments: [_toJSValue(name), _toJSValue(options)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func getFileHandle(name: String, options: FileSystemGetFileOptions? = nil) async throws -> FileSystemFileHandle {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.getFileHandle].function!(this: this, arguments: [_toJSValue(name), _toJSValue(options)]).fromJSValue()!
+        return try await _promise.value.fromJSValue()!
+    }
+
+    @inlinable public func getDirectoryHandle(name: String, options: FileSystemGetDirectoryOptions? = nil) -> JSPromise {
+        let this = jsObject
+        return this[Strings.getDirectoryHandle].function!(this: this, arguments: [_toJSValue(name), _toJSValue(options)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func getDirectoryHandle(name: String, options: FileSystemGetDirectoryOptions? = nil) async throws -> FileSystemDirectoryHandle {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.getDirectoryHandle].function!(this: this, arguments: [_toJSValue(name), _toJSValue(options)]).fromJSValue()!
+        return try await _promise.value.fromJSValue()!
+    }
+
+    @inlinable public func removeEntry(name: String, options: FileSystemRemoveOptions? = nil) -> JSPromise {
+        let this = jsObject
+        return this[Strings.removeEntry].function!(this: this, arguments: [_toJSValue(name), _toJSValue(options)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func removeEntry(name: String, options: FileSystemRemoveOptions? = nil) async throws {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.removeEntry].function!(this: this, arguments: [_toJSValue(name), _toJSValue(options)]).fromJSValue()!
+        _ = try await _promise.value
+    }
+
+    @inlinable public func resolve(possibleDescendant: FileSystemHandle) -> JSPromise {
+        let this = jsObject
+        return this[Strings.resolve].function!(this: this, arguments: [_toJSValue(possibleDescendant)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func resolve(possibleDescendant: FileSystemHandle) async throws -> [String]? {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.resolve].function!(this: this, arguments: [_toJSValue(possibleDescendant)]).fromJSValue()!
+        return try await _promise.value.fromJSValue()
+    }
+}
+
+public class FileSystemFileHandle: FileSystemHandle {
+    @inlinable override public class var constructor: JSFunction? { JSObject.global[Strings.FileSystemFileHandle].function }
+
+    public required init(unsafelyWrapping jsObject: JSObject) {
+        super.init(unsafelyWrapping: jsObject)
+    }
+
+    @inlinable public func getFile() -> JSPromise {
+        let this = jsObject
+        return this[Strings.getFile].function!(this: this, arguments: []).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func getFile() async throws -> File {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.getFile].function!(this: this, arguments: []).fromJSValue()!
+        return try await _promise.value.fromJSValue()!
+    }
+
+    @inlinable public func createWritable(options: FileSystemCreateWritableOptions? = nil) -> JSPromise {
+        let this = jsObject
+        return this[Strings.createWritable].function!(this: this, arguments: [_toJSValue(options)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func createWritable(options: FileSystemCreateWritableOptions? = nil) async throws -> FileSystemWritableFileStream {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.createWritable].function!(this: this, arguments: [_toJSValue(options)]).fromJSValue()!
+        return try await _promise.value.fromJSValue()!
+    }
+
+    @inlinable public func createSyncAccessHandle() -> JSPromise {
+        let this = jsObject
+        return this[Strings.createSyncAccessHandle].function!(this: this, arguments: []).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func createSyncAccessHandle() async throws -> FileSystemSyncAccessHandle {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.createSyncAccessHandle].function!(this: this, arguments: []).fromJSValue()!
+        return try await _promise.value.fromJSValue()!
+    }
+}
+
+public class FileSystemGetDirectoryOptions: BridgedDictionary {
+    public convenience init(create: Bool) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.create] = _toJSValue(create)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _create = ReadWriteAttribute(jsObject: object, name: Strings.create)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var create: Bool
+}
+
+public class FileSystemGetFileOptions: BridgedDictionary {
+    public convenience init(create: Bool) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.create] = _toJSValue(create)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _create = ReadWriteAttribute(jsObject: object, name: Strings.create)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var create: Bool
+}
+
+public class FileSystemHandle: JSBridgedClass {
+    @inlinable public class var constructor: JSFunction? { JSObject.global[Strings.FileSystemHandle].function }
+
+    public let jsObject: JSObject
+
+    public required init(unsafelyWrapping jsObject: JSObject) {
+        _kind = ReadonlyAttribute(jsObject: jsObject, name: Strings.kind)
+        _name = ReadonlyAttribute(jsObject: jsObject, name: Strings.name)
+        self.jsObject = jsObject
+    }
+
+    @ReadonlyAttribute
+    public var kind: FileSystemHandleKind
+
+    @ReadonlyAttribute
+    public var name: String
+
+    @inlinable public func isSameEntry(other: FileSystemHandle) -> JSPromise {
+        let this = jsObject
+        return this[Strings.isSameEntry].function!(this: this, arguments: [_toJSValue(other)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func isSameEntry(other: FileSystemHandle) async throws -> Bool {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.isSameEntry].function!(this: this, arguments: [_toJSValue(other)]).fromJSValue()!
+        return try await _promise.value.fromJSValue()!
+    }
+
+    @inlinable public func queryPermission(descriptor: FileSystemHandlePermissionDescriptor? = nil) -> JSPromise {
+        let this = jsObject
+        return this[Strings.queryPermission].function!(this: this, arguments: [_toJSValue(descriptor)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func queryPermission(descriptor: FileSystemHandlePermissionDescriptor? = nil) async throws -> PermissionState {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.queryPermission].function!(this: this, arguments: [_toJSValue(descriptor)]).fromJSValue()!
+        return try await _promise.value.fromJSValue()!
+    }
+
+    @inlinable public func requestPermission(descriptor: FileSystemHandlePermissionDescriptor? = nil) -> JSPromise {
+        let this = jsObject
+        return this[Strings.requestPermission].function!(this: this, arguments: [_toJSValue(descriptor)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func requestPermission(descriptor: FileSystemHandlePermissionDescriptor? = nil) async throws -> PermissionState {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.requestPermission].function!(this: this, arguments: [_toJSValue(descriptor)]).fromJSValue()!
+        return try await _promise.value.fromJSValue()!
+    }
+}
+
+public enum FileSystemHandleKind: JSString, JSValueCompatible {
+    case file = "file"
+    case directory = "directory"
+
+    @inlinable public static func construct(from jsValue: JSValue) -> Self? {
+        if let string = jsValue.jsString {
+            return Self(rawValue: string)
+        }
+        return nil
+    }
+
+    @inlinable public init?(string: String) {
+        self.init(rawValue: JSString(string))
+    }
+
+    @inlinable public var jsValue: JSValue { rawValue.jsValue }
+}
+
+public class FileSystemHandlePermissionDescriptor: BridgedDictionary {
+    public convenience init(mode: FileSystemPermissionMode) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.mode] = _toJSValue(mode)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _mode = ReadWriteAttribute(jsObject: object, name: Strings.mode)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var mode: FileSystemPermissionMode
+}
+
+public class FileSystemPermissionDescriptor: BridgedDictionary {
+    public convenience init(handle: FileSystemHandle, mode: FileSystemPermissionMode) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.handle] = _toJSValue(handle)
+        object[Strings.mode] = _toJSValue(mode)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _handle = ReadWriteAttribute(jsObject: object, name: Strings.handle)
+        _mode = ReadWriteAttribute(jsObject: object, name: Strings.mode)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var handle: FileSystemHandle
+
+    @ReadWriteAttribute
+    public var mode: FileSystemPermissionMode
+}
+
+public enum FileSystemPermissionMode: JSString, JSValueCompatible {
+    case read = "read"
+    case readwrite = "readwrite"
+
+    @inlinable public static func construct(from jsValue: JSValue) -> Self? {
+        if let string = jsValue.jsString {
+            return Self(rawValue: string)
+        }
+        return nil
+    }
+
+    @inlinable public init?(string: String) {
+        self.init(rawValue: JSString(string))
+    }
+
+    @inlinable public var jsValue: JSValue { rawValue.jsValue }
+}
+
+public class FileSystemReadWriteOptions: BridgedDictionary {
+    public convenience init(at: UInt64) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.at] = _toJSValue(at)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _at = ReadWriteAttribute(jsObject: object, name: Strings.at)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var at: UInt64
+}
+
+public class FileSystemRemoveOptions: BridgedDictionary {
+    public convenience init(recursive: Bool) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.recursive] = _toJSValue(recursive)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _recursive = ReadWriteAttribute(jsObject: object, name: Strings.recursive)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var recursive: Bool
+}
+
+public class FileSystemWritableFileStream: WritableStream {
+    @inlinable override public class var constructor: JSFunction? { JSObject.global[Strings.FileSystemWritableFileStream].function }
+
+    public required init(unsafelyWrapping jsObject: JSObject) {
+        super.init(unsafelyWrapping: jsObject)
+    }
+
+    @inlinable public func write(data: FileSystemWriteChunkType) -> JSPromise {
+        let this = jsObject
+        return this[Strings.write].function!(this: this, arguments: [_toJSValue(data)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func write(data: FileSystemWriteChunkType) async throws {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.write].function!(this: this, arguments: [_toJSValue(data)]).fromJSValue()!
+        _ = try await _promise.value
+    }
+
+    @inlinable public func seek(position: UInt64) -> JSPromise {
+        let this = jsObject
+        return this[Strings.seek].function!(this: this, arguments: [_toJSValue(position)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func seek(position: UInt64) async throws {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.seek].function!(this: this, arguments: [_toJSValue(position)]).fromJSValue()!
+        _ = try await _promise.value
+    }
+
+    @inlinable public func truncate(size: UInt64) -> JSPromise {
+        let this = jsObject
+        return this[Strings.truncate].function!(this: this, arguments: [_toJSValue(size)]).fromJSValue()!
+    }
+
+    @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+    @inlinable public func truncate(size: UInt64) async throws {
+        let this = jsObject
+        let _promise: JSPromise = this[Strings.truncate].function!(this: this, arguments: [_toJSValue(size)]).fromJSValue()!
+        _ = try await _promise.value
+    }
+}
+
+public class OpenFilePickerOptions: BridgedDictionary {
+    public convenience init(multiple: Bool) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.multiple] = _toJSValue(multiple)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _multiple = ReadWriteAttribute(jsObject: object, name: Strings.multiple)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var multiple: Bool
+}
+
+public class SaveFilePickerOptions: BridgedDictionary {
+    public convenience init(suggestedName: String?) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.suggestedName] = _toJSValue(suggestedName)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _suggestedName = ReadWriteAttribute(jsObject: object, name: Strings.suggestedName)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var suggestedName: String?
+}
+
+public enum WellKnownDirectory: JSString, JSValueCompatible {
+    case desktop = "desktop"
+    case documents = "documents"
+    case downloads = "downloads"
+    case music = "music"
+    case pictures = "pictures"
+    case videos = "videos"
+
+    @inlinable public static func construct(from jsValue: JSValue) -> Self? {
+        if let string = jsValue.jsString {
+            return Self(rawValue: string)
+        }
+        return nil
+    }
+
+    @inlinable public init?(string: String) {
+        self.init(rawValue: JSString(string))
+    }
+
+    @inlinable public var jsValue: JSValue { rawValue.jsValue }
+}
+
+public enum WriteCommandType: JSString, JSValueCompatible {
+    case write = "write"
+    case seek = "seek"
+    case truncate = "truncate"
+
+    @inlinable public static func construct(from jsValue: JSValue) -> Self? {
+        if let string = jsValue.jsString {
+            return Self(rawValue: string)
+        }
+        return nil
+    }
+
+    @inlinable public init?(string: String) {
+        self.init(rawValue: JSString(string))
+    }
+
+    @inlinable public var jsValue: JSValue { rawValue.jsValue }
+}
+
+public class WriteParams: BridgedDictionary {
+    public convenience init(type: WriteCommandType, size: UInt64?, position: UInt64?, data: Blob_or_BufferSource_or_String?) {
+        let object = JSObject.global[Strings.Object].function!.new()
+        object[Strings.type] = _toJSValue(type)
+        object[Strings.size] = _toJSValue(size)
+        object[Strings.position] = _toJSValue(position)
+        object[Strings.data] = _toJSValue(data)
+        self.init(unsafelyWrapping: object)
+    }
+
+    public required init(unsafelyWrapping object: JSObject) {
+        _type = ReadWriteAttribute(jsObject: object, name: Strings.type)
+        _size = ReadWriteAttribute(jsObject: object, name: Strings.size)
+        _position = ReadWriteAttribute(jsObject: object, name: Strings.position)
+        _data = ReadWriteAttribute(jsObject: object, name: Strings.data)
+        super.init(unsafelyWrapping: object)
+    }
+
+    @ReadWriteAttribute
+    public var type: WriteCommandType
+
+    @ReadWriteAttribute
+    public var size: UInt64?
+
+    @ReadWriteAttribute
+    public var position: UInt64?
+
+    @ReadWriteAttribute
+    public var data: Blob_or_BufferSource_or_String?
+}
+
+@usableFromInline enum Strings {
+    @usableFromInline static let _self: JSString = "self"
+    @usableFromInline static let FileSystemDirectoryHandle: JSString = "FileSystemDirectoryHandle"
+    @usableFromInline static let FileSystemFileHandle: JSString = "FileSystemFileHandle"
+    @usableFromInline static let FileSystemHandle: JSString = "FileSystemHandle"
+    @usableFromInline static let FileSystemWritableFileStream: JSString = "FileSystemWritableFileStream"
+    @usableFromInline static let Object: JSString = "Object"
+    @usableFromInline static let accept: JSString = "accept"
+    @usableFromInline static let at: JSString = "at"
+    @usableFromInline static let create: JSString = "create"
+    @usableFromInline static let createSyncAccessHandle: JSString = "createSyncAccessHandle"
+    @usableFromInline static let createWritable: JSString = "createWritable"
+    @usableFromInline static let data: JSString = "data"
+    @usableFromInline static let description: JSString = "description"
+    @usableFromInline static let excludeAcceptAllOption: JSString = "excludeAcceptAllOption"
+    @usableFromInline static let getDirectoryHandle: JSString = "getDirectoryHandle"
+    @usableFromInline static let getFile: JSString = "getFile"
+    @usableFromInline static let getFileHandle: JSString = "getFileHandle"
+    @usableFromInline static let handle: JSString = "handle"
+    @usableFromInline static let id: JSString = "id"
+    @usableFromInline static let isSameEntry: JSString = "isSameEntry"
+    @usableFromInline static let keepExistingData: JSString = "keepExistingData"
+    @usableFromInline static let kind: JSString = "kind"
+    @usableFromInline static let mode: JSString = "mode"
+    @usableFromInline static let multiple: JSString = "multiple"
+    @usableFromInline static let name: JSString = "name"
+    @usableFromInline static let position: JSString = "position"
+    @usableFromInline static let queryPermission: JSString = "queryPermission"
+    @usableFromInline static let recursive: JSString = "recursive"
+    @usableFromInline static let removeEntry: JSString = "removeEntry"
+    @usableFromInline static let requestPermission: JSString = "requestPermission"
+    @usableFromInline static let resolve: JSString = "resolve"
+    @usableFromInline static let seek: JSString = "seek"
+    @usableFromInline static let size: JSString = "size"
+    @usableFromInline static let startIn: JSString = "startIn"
+    @usableFromInline static let suggestedName: JSString = "suggestedName"
+    @usableFromInline static let toString: JSString = "toString"
+    @usableFromInline static let truncate: JSString = "truncate"
+    @usableFromInline static let type: JSString = "type"
+    @usableFromInline static let types: JSString = "types"
+    @usableFromInline static let write: JSString = "write"
+}
+
+public protocol Any_Blob_or_BufferSource_or_String: ConvertibleToJSValue {}
+extension Blob: Any_Blob_or_BufferSource_or_String {}
+extension BufferSource: Any_Blob_or_BufferSource_or_String {}
+extension String: Any_Blob_or_BufferSource_or_String {}
+
+public enum Blob_or_BufferSource_or_String: JSValueCompatible, Any_Blob_or_BufferSource_or_String {
+    case blob(Blob)
+    case bufferSource(BufferSource)
+    case string(String)
+
+    init(_ blob: Blob) {
+        let val: Blob_or_BufferSource_or_String = .blob(blob)
+        self = val
+    }
+
+    init(_ bufferSource: BufferSource) {
+        let val: Blob_or_BufferSource_or_String = .bufferSource(bufferSource)
+        self = val
+    }
+
+    init(_ arrayBuffer: ArrayBuffer) {
+        let val: BufferSource = .arrayBuffer(arrayBuffer)
+        self = .init(val)
+    }
+
+    init(_ arrayBufferView: ArrayBufferView) {
+        let val: BufferSource = .arrayBufferView(arrayBufferView)
+        self = .init(val)
+    }
+
+    init(_ string: String) {
+        let val: Blob_or_BufferSource_or_String = .string(string)
+        self = val
+    }
+
+    public var blob: Blob? {
+        switch self {
+        case let .blob(blob): return blob
+        default: return nil
+        }
+    }
+
+    public var bufferSource: BufferSource? {
+        switch self {
+        case let .bufferSource(bufferSource): return bufferSource
+        default: return nil
+        }
+    }
+
+    public var string: String? {
+        switch self {
+        case let .string(string): return string
+        default: return nil
+        }
+    }
+
+    public static func construct(from value: JSValue) -> Self? {
+        if let blob: Blob = value.fromJSValue() {
+            return .blob(blob)
+        }
+        if let bufferSource: BufferSource = value.fromJSValue() {
+            return .bufferSource(bufferSource)
+        }
+        if let string: String = value.fromJSValue() {
+            return .string(string)
+        }
+        return nil
+    }
+
+    public var jsValue: JSValue {
+        switch self {
+        case let .blob(blob):
+            return blob.jsValue
+        case let .bufferSource(bufferSource):
+            return bufferSource.jsValue
+        case let .string(string):
+            return string.jsValue
+        }
+    }
+}
+
+public protocol Any_FileSystemWriteChunkType: ConvertibleToJSValue {}
+extension Blob: Any_FileSystemWriteChunkType {}
+extension BufferSource: Any_FileSystemWriteChunkType {}
+extension String: Any_FileSystemWriteChunkType {}
+extension WriteParams: Any_FileSystemWriteChunkType {}
+
+public enum FileSystemWriteChunkType: JSValueCompatible, Any_FileSystemWriteChunkType {
+    case blob(Blob)
+    case bufferSource(BufferSource)
+    case string(String)
+    case writeParams(WriteParams)
+
+    init(_ blob: Blob) {
+        let val: FileSystemWriteChunkType = .blob(blob)
+        self = val
+    }
+
+    init(_ bufferSource: BufferSource) {
+        let val: FileSystemWriteChunkType = .bufferSource(bufferSource)
+        self = val
+    }
+
+    init(_ arrayBuffer: ArrayBuffer) {
+        let val: BufferSource = .arrayBuffer(arrayBuffer)
+        self = .init(val)
+    }
+
+    init(_ arrayBufferView: ArrayBufferView) {
+        let val: BufferSource = .arrayBufferView(arrayBufferView)
+        self = .init(val)
+    }
+
+    init(_ string: String) {
+        let val: FileSystemWriteChunkType = .string(string)
+        self = val
+    }
+
+    init(_ writeParams: WriteParams) {
+        let val: FileSystemWriteChunkType = .writeParams(writeParams)
+        self = val
+    }
+
+    public var blob: Blob? {
+        switch self {
+        case let .blob(blob): return blob
+        default: return nil
+        }
+    }
+
+    public var bufferSource: BufferSource? {
+        switch self {
+        case let .bufferSource(bufferSource): return bufferSource
+        default: return nil
+        }
+    }
+
+    public var string: String? {
+        switch self {
+        case let .string(string): return string
+        default: return nil
+        }
+    }
+
+    public var writeParams: WriteParams? {
+        switch self {
+        case let .writeParams(writeParams): return writeParams
+        default: return nil
+        }
+    }
+
+    public static func construct(from value: JSValue) -> Self? {
+        if let blob: Blob = value.fromJSValue() {
+            return .blob(blob)
+        }
+        if let bufferSource: BufferSource = value.fromJSValue() {
+            return .bufferSource(bufferSource)
+        }
+        if let string: String = value.fromJSValue() {
+            return .string(string)
+        }
+        if let writeParams: WriteParams = value.fromJSValue() {
+            return .writeParams(writeParams)
+        }
+        return nil
+    }
+
+    public var jsValue: JSValue {
+        switch self {
+        case let .blob(blob):
+            return blob.jsValue
+        case let .bufferSource(bufferSource):
+            return bufferSource.jsValue
+        case let .string(string):
+            return string.jsValue
+        case let .writeParams(writeParams):
+            return writeParams.jsValue
+        }
+    }
+}
+
+public protocol Any_StartInDirectory: ConvertibleToJSValue {}
+extension FileSystemHandle: Any_StartInDirectory {}
+extension WellKnownDirectory: Any_StartInDirectory {}
+
+public enum StartInDirectory: JSValueCompatible, Any_StartInDirectory {
+    case fileSystemHandle(FileSystemHandle)
+    case wellKnownDirectory(WellKnownDirectory)
+
+    init(_ fileSystemHandle: FileSystemHandle) {
+        let val: StartInDirectory = .fileSystemHandle(fileSystemHandle)
+        self = val
+    }
+
+    init(_ wellKnownDirectory: WellKnownDirectory) {
+        let val: StartInDirectory = .wellKnownDirectory(wellKnownDirectory)
+        self = val
+    }
+
+    public var fileSystemHandle: FileSystemHandle? {
+        switch self {
+        case let .fileSystemHandle(fileSystemHandle): return fileSystemHandle
+        default: return nil
+        }
+    }
+
+    public var wellKnownDirectory: WellKnownDirectory? {
+        switch self {
+        case let .wellKnownDirectory(wellKnownDirectory): return wellKnownDirectory
+        default: return nil
+        }
+    }
+
+    public static func construct(from value: JSValue) -> Self? {
+        if let fileSystemHandle: FileSystemHandle = value.fromJSValue() {
+            return .fileSystemHandle(fileSystemHandle)
+        }
+        if let wellKnownDirectory: WellKnownDirectory = value.fromJSValue() {
+            return .wellKnownDirectory(wellKnownDirectory)
+        }
+        return nil
+    }
+
+    public var jsValue: JSValue {
+        switch self {
+        case let .fileSystemHandle(fileSystemHandle):
+            return fileSystemHandle.jsValue
+        case let .wellKnownDirectory(wellKnownDirectory):
+            return wellKnownDirectory.jsValue
+        }
+    }
+}
+
+public protocol Any_String_or_seq_of_String: ConvertibleToJSValue {}
+extension String: Any_String_or_seq_of_String {}
+extension Array: Any_String_or_seq_of_String where Element == String {}
+
+public enum String_or_seq_of_String: JSValueCompatible, Any_String_or_seq_of_String {
+    case string(String)
+    case seq_of_String([String])
+
+    init(_ string: String) {
+        let val: String_or_seq_of_String = .string(string)
+        self = val
+    }
+
+    init(_ seq_of_String: [String]) {
+        let val: String_or_seq_of_String = .seq_of_String(seq_of_String)
+        self = val
+    }
+
+    public var string: String? {
+        switch self {
+        case let .string(string): return string
+        default: return nil
+        }
+    }
+
+    public var seq_of_String: [String]? {
+        switch self {
+        case let .seq_of_String(seq_of_String): return seq_of_String
+        default: return nil
+        }
+    }
+
+    public static func construct(from value: JSValue) -> Self? {
+        if let string: String = value.fromJSValue() {
+            return .string(string)
+        }
+        if let seq_of_String: [String] = value.fromJSValue() {
+            return .seq_of_String(seq_of_String)
+        }
+        return nil
+    }
+
+    public var jsValue: JSValue {
+        switch self {
+        case let .string(string):
+            return string.jsValue
+        case let .seq_of_String(seq_of_String):
+            return seq_of_String.jsValue
+        }
+    }
+}
diff --git a/Sources/WebIDLToSwift/Module.swift b/Sources/WebIDLToSwift/Module.swift
index 6036b9b..610bd0a 100644
--- a/Sources/WebIDLToSwift/Module.swift
+++ b/Sources/WebIDLToSwift/Module.swift
@@ -91,4 +91,9 @@ let modules = [
         idlModules: ["SVG", "css-masking", "svg-animations"],
         dependencies: ["DOM", "WebAPIBase"]
     ),
+    Module(
+        swiftModule: "FileSystem",
+        idlModules: ["fs", "file-system-access"],
+        dependencies: ["DOM", "WebAPIBase"]
+    ),
 ]