diff --git a/src/node/types/callback.ts b/src/node/types/callback.ts
new file mode 100644
index 000000000..a5dbd9360
--- /dev/null
+++ b/src/node/types/callback.ts
@@ -0,0 +1,102 @@
+import type { PathLike, symlink } from 'fs';
+import type * as misc from './misc';
+import type * as opts from './options';
+
+export interface FsCallbackApi {
+  open(path: PathLike, flags: misc.TFlags, /* ... */ callback: misc.TCallback<number>);
+  open(path: PathLike, flags: misc.TFlags, mode: misc.TMode, callback: misc.TCallback<number>);
+  close(fd: number, callback: misc.TCallback<void>): void;
+  read(
+    fd: number,
+    buffer: Buffer | ArrayBufferView | DataView,
+    offset: number,
+    length: number,
+    position: number,
+    callback: (err?: Error | null, bytesRead?: number, buffer?: Buffer | ArrayBufferView | DataView) => void,
+  ): void;
+  readFile(id: misc.TFileId, callback: misc.TCallback<misc.TDataOut>);
+  readFile(id: misc.TFileId, options: opts.IReadFileOptions | string, callback: misc.TCallback<misc.TDataOut>);
+  write(fd: number, buffer: Buffer | ArrayBufferView | DataView, callback: (...args) => void);
+  write(fd: number, buffer: Buffer | ArrayBufferView | DataView, offset: number, callback: (...args) => void);
+  write(
+    fd: number,
+    buffer: Buffer | ArrayBufferView | DataView,
+    offset: number,
+    length: number,
+    callback: (...args) => void,
+  );
+  write(
+    fd: number,
+    buffer: Buffer | ArrayBufferView | DataView,
+    offset: number,
+    length: number,
+    position: number,
+    callback: (...args) => void,
+  );
+  write(fd: number, str: string, callback: (...args) => void);
+  write(fd: number, str: string, position: number, callback: (...args) => void);
+  write(fd: number, str: string, position: number, encoding: BufferEncoding, callback: (...args) => void);
+  writeFile(id: misc.TFileId, data: misc.TData, callback: misc.TCallback<void>);
+  writeFile(id: misc.TFileId, data: misc.TData, options: opts.IWriteFileOptions | string, callback: misc.TCallback<void>);
+  copyFile(src: PathLike, dest: PathLike, callback: misc.TCallback<void>);
+  copyFile(src: PathLike, dest: PathLike, flags: misc.TFlagsCopy, callback: misc.TCallback<void>);
+  link(existingPath: PathLike, newPath: PathLike, callback: misc.TCallback<void>): void;
+  unlink(path: PathLike, callback: misc.TCallback<void>): void;
+  symlink(target: PathLike, path: PathLike, callback: misc.TCallback<void>);
+  symlink(target: PathLike, path: PathLike, type: symlink.Type, callback: misc.TCallback<void>);
+  realpath(path: PathLike, callback: misc.TCallback<misc.TDataOut>);
+  realpath(path: PathLike, options: opts.IRealpathOptions | string, callback: misc.TCallback<misc.TDataOut>);
+  lstat(path: PathLike, callback: misc.TCallback<misc.IStats>): void;
+  lstat(path: PathLike, options: opts.IStatOptions, callback: misc.TCallback<misc.IStats>): void;
+  stat(path: PathLike, callback: misc.TCallback<misc.IStats>): void;
+  stat(path: PathLike, options: opts.IStatOptions, callback: misc.TCallback<misc.IStats>): void;
+  fstat(fd: number, callback: misc.TCallback<misc.IStats>): void;
+  fstat(fd: number, options: opts.IFStatOptions, callback: misc.TCallback<misc.IStats>): void;
+  rename(oldPath: PathLike, newPath: PathLike, callback: misc.TCallback<void>): void;
+  exists(path: PathLike, callback: (exists: boolean) => void): void;
+  access(path: PathLike, callback: misc.TCallback<void>);
+  access(path: PathLike, mode: number, callback: misc.TCallback<void>);
+  appendFile(id: misc.TFileId, data: misc.TData, callback: misc.TCallback<void>);
+  appendFile(id: misc.TFileId, data: misc.TData, options: opts.IAppendFileOptions | string, callback: misc.TCallback<void>);
+  readdir(path: PathLike, callback: misc.TCallback<misc.TDataOut[] | misc.IDirent[]>);
+  readdir(path: PathLike, options: opts.IReaddirOptions | string, callback: misc.TCallback<misc.TDataOut[] | misc.IDirent[]>);
+  readlink(path: PathLike, callback: misc.TCallback<misc.TDataOut>);
+  readlink(path: PathLike, options: opts.IOptions, callback: misc.TCallback<misc.TDataOut>);
+  fsyncSync(fd: number): void;
+  fsync(fd: number, callback: misc.TCallback<void>): void;
+  fdatasync(fd: number, callback: misc.TCallback<void>): void;
+  ftruncate(fd: number, callback: misc.TCallback<void>);
+  ftruncate(fd: number, len: number, callback: misc.TCallback<void>);
+  truncate(id: misc.TFileId, callback: misc.TCallback<void>);
+  truncate(id: misc.TFileId, len: number, callback: misc.TCallback<void>);
+  futimes(fd: number, atime: misc.TTime, mtime: misc.TTime, callback: misc.TCallback<void>): void;
+  utimes(path: PathLike, atime: misc.TTime, mtime: misc.TTime, callback: misc.TCallback<void>): void;
+  mkdir(path: PathLike, callback: misc.TCallback<void>);
+  mkdir(path: PathLike, mode: misc.TMode | (opts.IMkdirOptions & { recursive?: false }), callback: misc.TCallback<void>);
+  mkdir(path: PathLike, mode: opts.IMkdirOptions & { recursive: true }, callback: misc.TCallback<string>);
+  mkdir(path: PathLike, mode: misc.TMode | opts.IMkdirOptions, callback: misc.TCallback<string>);
+  mkdirp(path: PathLike, callback: misc.TCallback<string>);
+  mkdirp(path: PathLike, mode: misc.TMode, callback: misc.TCallback<string>);
+  mkdtemp(prefix: string, callback: misc.TCallback<void>): void;
+  mkdtemp(prefix: string, options: opts.IOptions, callback: misc.TCallback<void>);
+  rmdir(path: PathLike, callback: misc.TCallback<void>);
+  rmdir(path: PathLike, options: opts.IRmdirOptions, callback: misc.TCallback<void>);
+  rm(path: PathLike, callback: misc.TCallback<void>): void;
+  rm(path: PathLike, options: opts.IRmOptions, callback: misc.TCallback<void>): void;
+  fchmod(fd: number, mode: misc.TMode, callback: misc.TCallback<void>): void;
+  chmod(path: PathLike, mode: misc.TMode, callback: misc.TCallback<void>): void;
+  lchmod(path: PathLike, mode: misc.TMode, callback: misc.TCallback<void>): void;
+  fchown(fd: number, uid: number, gid: number, callback: misc.TCallback<void>): void;
+  chown(path: PathLike, uid: number, gid: number, callback: misc.TCallback<void>): void;
+  lchown(path: PathLike, uid: number, gid: number, callback: misc.TCallback<void>): void;
+  watchFile(path: PathLike, listener: (curr: misc.IStats, prev: misc.IStats) => void): misc.IStatWatcher;
+  watchFile(path: PathLike, options: opts.IWatchFileOptions, listener: (curr: misc.IStats, prev: misc.IStats) => void): misc.IStatWatcher;
+  unwatchFile(path: PathLike, listener?: (curr: misc.IStats, prev: misc.IStats) => void): void;
+  createReadStream(path: PathLike, options?: opts.IReadStreamOptions | string): misc.IReadStream;
+  createWriteStream(path: PathLike, options?: opts.IWriteStreamOptions | string): misc.IWriteStream;
+  watch(
+    path: PathLike,
+    options?: opts.IWatchOptions | string,
+    listener?: (eventType: string, filename: string) => void,
+  ): misc.IFSWatcher;
+}
diff --git a/src/node/types/index.ts b/src/node/types/index.ts
new file mode 100644
index 000000000..5842917e1
--- /dev/null
+++ b/src/node/types/index.ts
@@ -0,0 +1,7 @@
+import type {FsCallbackApi} from "./callback";
+import type {FsPromisesApi} from "./promises";
+import type {FsSynchronousApi} from "./sync";
+
+export interface FsApi extends FsCallbackApi, FsSynchronousApi {
+  promises: FsPromisesApi;
+}
diff --git a/src/node/types/misc.ts b/src/node/types/misc.ts
new file mode 100644
index 000000000..25dc3553f
--- /dev/null
+++ b/src/node/types/misc.ts
@@ -0,0 +1,136 @@
+import type {PathLike, symlink} from 'fs';
+import type {constants} from '../../constants';
+import type {EventEmitter} from 'events';
+import type {TSetTimeout} from '../../setTimeoutUnref';
+import type {IAppendFileOptions, IReadFileOptions, IReadStreamOptions, IStatOptions, IWriteFileOptions, IWriteStreamOptions} from './options';
+import type {Readable, Writable} from 'stream';
+
+export {PathLike, symlink};
+
+export type TDataOut = string | Buffer; // Data formats we give back to users.
+export type TEncodingExtended = BufferEncoding | 'buffer';
+export type TFileId = PathLike | number; // Number is used as a file descriptor.
+export type TData = TDataOut | ArrayBufferView | DataView; // Data formats users can give us.
+export type TFlags = string | number;
+export type TMode = string | number; // Mode can be a String, although docs say it should be a Number.
+export type TTime = number | string | Date;
+export type TCallback<TData> = (error?: IError | null, data?: TData) => void;
+
+export interface IError extends Error {
+  code?: string;
+}
+
+export type TFlagsCopy =
+  | typeof constants.COPYFILE_EXCL
+  | typeof constants.COPYFILE_FICLONE
+  | typeof constants.COPYFILE_FICLONE_FORCE;
+
+export type TStatNumber = number | bigint;
+
+export interface IStats<T = TStatNumber> {
+  uid: T;
+  gid: T;
+  rdev: T;
+  blksize: T;
+  ino: T;
+  size: T;
+  blocks: T;
+  atime: Date;
+  mtime: Date;
+  ctime: Date;
+  birthtime: Date;
+  atimeMs: T;
+  mtimeMs: T;
+  ctimeMs: T;
+  birthtimeMs: T;
+  dev: T;
+  mode: T;
+  nlink: T;
+  isDirectory(): boolean;
+  isFile(): boolean;
+  isBlockDevice(): boolean;
+  isCharacterDevice(): boolean;
+  isSymbolicLink(): boolean;
+  isFIFO(): boolean;
+  isSocket(): boolean;
+}
+
+export interface IDirent {
+  name: TDataOut;
+  isDirectory(): boolean;
+  isFile(): boolean;
+  isBlockDevice(): boolean;
+  isCharacterDevice(): boolean;
+  isSymbolicLink(): boolean;
+  isFIFO(): boolean;
+  isSocket(): boolean;
+}
+
+export interface IStatWatcher extends EventEmitter {
+  filename: string;
+  interval: number;
+  timeoutRef?;
+  setTimeout: TSetTimeout;
+  prev: IStats;
+  start(path: string, persistent?: boolean, interval?: number): void;
+  stop(): void;
+}
+
+export interface IReadStream extends Readable {
+  new (path: PathLike, options: IReadStreamOptions);
+  open();
+  close(callback: TCallback<void>);
+  bytesRead: number;
+  path: string;
+}
+
+export interface IWriteStream extends Writable {
+  bytesWritten: number;
+  path: string;
+  new (path: PathLike, options: IWriteStreamOptions);
+  open();
+  close();
+}
+
+export interface IFSWatcher extends EventEmitter {
+  start(
+    path: PathLike,
+    persistent?: boolean,
+    recursive?: boolean,
+    encoding?: BufferEncoding,
+  ): void;
+  close(): void;
+}
+
+export interface IFileHandle {
+  fd: number;
+  appendFile(data: TData, options?: IAppendFileOptions | string): Promise<void>;
+  chmod(mode: TMode): Promise<void>;
+  chown(uid: number, gid: number): Promise<void>;
+  close(): Promise<void>;
+  datasync(): Promise<void>;
+  read(buffer: Buffer | Uint8Array, offset: number, length: number, position: number): Promise<TFileHandleReadResult>;
+  readFile(options?: IReadFileOptions | string): Promise<TDataOut>;
+  stat(options?: IStatOptions): Promise<IStats>;
+  truncate(len?: number): Promise<void>;
+  utimes(atime: TTime, mtime: TTime): Promise<void>;
+  write(
+    buffer: Buffer | ArrayBufferView | DataView,
+    offset?: number,
+    length?: number,
+    position?: number,
+  ): Promise<TFileHandleWriteResult>;
+  writeFile(data: TData, options?: IWriteFileOptions): Promise<void>;
+}
+
+export type TFileHandle = PathLike | IFileHandle;
+
+export interface TFileHandleReadResult {
+  bytesRead: number;
+  buffer: Buffer | Uint8Array;
+}
+
+export interface TFileHandleWriteResult {
+  bytesWritten: number;
+  buffer: Buffer | Uint8Array;
+}
diff --git a/src/node/types/options.ts b/src/node/types/options.ts
new file mode 100644
index 000000000..354e2a340
--- /dev/null
+++ b/src/node/types/options.ts
@@ -0,0 +1,85 @@
+import type {TEncodingExtended, TFlags, TMode} from "./misc";
+
+export interface IOptions {
+  encoding?: BufferEncoding | TEncodingExtended;
+}
+
+export interface IFileOptions extends IOptions {
+  mode?: TMode;
+  flag?: TFlags;
+}
+
+export interface IWriteFileOptions extends IFileOptions {}
+
+export interface IReadFileOptions extends IOptions {
+  flag?: string;
+}
+
+export interface IRealpathOptions {
+  encoding?: TEncodingExtended;
+}
+
+export interface IAppendFileOptions extends IFileOptions {}
+
+export interface IStatOptions {
+  bigint?: boolean;
+  throwIfNoEntry?: boolean;
+}
+
+export interface IFStatOptions {
+  bigint?: boolean;
+}
+
+export interface IAppendFileOptions extends IFileOptions {}
+
+export interface IReaddirOptions extends IOptions {
+  withFileTypes?: boolean;
+}
+
+export interface IMkdirOptions {
+  mode?: TMode;
+  recursive?: boolean;
+}
+
+export interface IRmdirOptions {
+  /** @deprecated */
+  recursive?: boolean;
+  maxRetries?: number;
+  retryDelay?: number;
+}
+
+export interface IRmOptions {
+  force?: boolean;
+  maxRetries?: number;
+  recursive?: boolean;
+  retryDelay?: number;
+}
+
+export interface IWatchFileOptions {
+  persistent?: boolean;
+  interval?: number;
+}
+
+export interface IReadStreamOptions {
+  flags?: TFlags;
+  encoding?: BufferEncoding;
+  fd?: number;
+  mode?: TMode;
+  autoClose?: boolean;
+  start?: number;
+  end?: number;
+}
+
+export interface IWriteStreamOptions {
+  flags?: TFlags;
+  defaultEncoding?: BufferEncoding;
+  fd?: number;
+  mode?: TMode;
+  autoClose?: boolean;
+  start?: number;
+}
+
+export interface IWatchOptions extends IOptions {
+  persistent?: boolean;
+  recursive?: boolean;
+}
diff --git a/src/node/types/promises.ts b/src/node/types/promises.ts
new file mode 100644
index 000000000..e71ac1885
--- /dev/null
+++ b/src/node/types/promises.ts
@@ -0,0 +1,30 @@
+import * as misc from "./misc";
+import * as opts from "./options";
+
+export interface FsPromisesApi {
+  access(path: misc.PathLike, mode?: number): Promise<void>;
+  appendFile(path: misc.TFileHandle, data: misc.TData, options?: opts.IAppendFileOptions | string): Promise<void>;
+  chmod(path: misc.PathLike, mode: misc.TMode): Promise<void>;
+  chown(path: misc.PathLike, uid: number, gid: number): Promise<void>;
+  copyFile(src: misc.PathLike, dest: misc.PathLike, flags?: misc.TFlagsCopy): Promise<void>;
+  lchmod(path: misc.PathLike, mode: misc.TMode): Promise<void>;
+  lchown(path: misc.PathLike, uid: number, gid: number): Promise<void>;
+  link(existingPath: misc.PathLike, newPath: misc.PathLike): Promise<void>;
+  lstat(path: misc.PathLike, options?: opts.IStatOptions): Promise<misc.IStats>;
+  mkdir(path: misc.PathLike, options?: misc.TMode | opts.IMkdirOptions): Promise<void>;
+  mkdtemp(prefix: string, options?: opts.IOptions): Promise<misc.TDataOut>;
+  open(path: misc.PathLike, flags: misc.TFlags, mode?: misc.TMode): Promise<misc.IFileHandle>;
+  readdir(path: misc.PathLike, options?: opts.IReaddirOptions | string): Promise<misc.TDataOut[] | misc.IDirent[]>;
+  readFile(id: misc.TFileHandle, options?: opts.IReadFileOptions | string): Promise<misc.TDataOut>;
+  readlink(path: misc.PathLike, options?: opts.IOptions): Promise<misc.TDataOut>;
+  realpath(path: misc.PathLike, options?: opts.IRealpathOptions | string): Promise<misc.TDataOut>;
+  rename(oldPath: misc.PathLike, newPath: misc.PathLike): Promise<void>;
+  rmdir(path: misc.PathLike, options?: opts.IRmdirOptions): Promise<void>;
+  rm(path: misc.PathLike, options?: opts.IRmOptions): Promise<void>;
+  stat(path: misc.PathLike, options?: opts.IStatOptions): Promise<misc.IStats>;
+  symlink(target: misc.PathLike, path: misc.PathLike, type?: misc.symlink.Type): Promise<void>;
+  truncate(path: misc.PathLike, len?: number): Promise<void>;
+  unlink(path: misc.PathLike): Promise<void>;
+  utimes(path: misc.PathLike, atime: misc.TTime, mtime: misc.TTime): Promise<void>;
+  writeFile(id: misc.TFileHandle, data: misc.TData, options?: opts.IWriteFileOptions): Promise<void>;
+}
diff --git a/src/node/types/sync.ts b/src/node/types/sync.ts
new file mode 100644
index 000000000..0e7a1eb3d
--- /dev/null
+++ b/src/node/types/sync.ts
@@ -0,0 +1,71 @@
+import type { PathLike, symlink } from 'fs';
+import type * as misc from './misc';
+import type * as opts from './options';
+
+export interface FsSynchronousApi {
+  openSync(path: PathLike, flags: misc.TFlags, mode?: misc.TMode): number;
+  closeSync(fd: number): void;
+  readSync(
+    fd: number,
+    buffer: Buffer | ArrayBufferView | DataView,
+    offset: number,
+    length: number,
+    position: number,
+  ): number;
+  readFileSync(file: misc.TFileId, options?: opts.IReadFileOptions | string): misc.TDataOut;
+  writeSync(
+    fd: number,
+    buffer: Buffer | ArrayBufferView | DataView,
+    offset?: number,
+    length?: number,
+    position?: number,
+  ): number;
+  writeSync(fd: number, str: string, position?: number, encoding?: BufferEncoding): number;
+  writeFileSync(id: misc.TFileId, data: misc.TData, options?: opts.IWriteFileOptions): void;
+  copyFileSync(src: PathLike, dest: PathLike, flags?: misc.TFlagsCopy): void;
+  linkSync(existingPath: PathLike, newPath: PathLike): void;
+  unlinkSync(path: PathLike): void;
+  symlinkSync(target: PathLike, path: PathLike, type?: symlink.Type): void;
+  realpathSync(path: PathLike, options?: opts.IRealpathOptions | string): misc.TDataOut;
+  lstatSync(path: PathLike): misc.IStats<number>;
+  lstatSync(path: PathLike, options: { throwIfNoEntry?: true | undefined }): misc.IStats<number>;
+  lstatSync(path: PathLike, options: { bigint: false; throwIfNoEntry?: true | undefined }): misc.IStats<number>;
+  lstatSync(path: PathLike, options: { bigint: true; throwIfNoEntry?: true | undefined }): misc.IStats<bigint>;
+  lstatSync(path: PathLike, options: { throwIfNoEntry: false }): misc.IStats<number> | undefined;
+  lstatSync(path: PathLike, options: { bigint: false; throwIfNoEntry: false }): misc.IStats<number> | undefined;
+  lstatSync(path: PathLike, options: { bigint: true; throwIfNoEntry: false }): misc.IStats<bigint> | undefined;
+  statSync(path: PathLike): misc.IStats<number>;
+  statSync(path: PathLike, options: { throwIfNoEntry?: true }): misc.IStats<number>;
+  statSync(path: PathLike, options: { throwIfNoEntry: false }): misc.IStats<number> | undefined;
+  statSync(path: PathLike, options: { bigint: false; throwIfNoEntry?: true }): misc.IStats<number>;
+  statSync(path: PathLike, options: { bigint: true; throwIfNoEntry?: true }): misc.IStats<bigint>;
+  statSync(path: PathLike, options: { bigint: false; throwIfNoEntry: false }): misc.IStats<number> | undefined;
+  statSync(path: PathLike, options: { bigint: true; throwIfNoEntry: false }): misc.IStats<bigint> | undefined;
+  fstatSync(fd: number): misc.IStats<number>;
+  fstatSync(fd: number, options: { bigint: false }): misc.IStats<number>;
+  fstatSync(fd: number, options: { bigint: true }): misc.IStats<bigint>;
+  renameSync(oldPath: PathLike, newPath: PathLike): void;
+  existsSync(path: PathLike): boolean;
+  accessSync(path: PathLike, mode?: number): void;
+  appendFileSync(id: misc.TFileId, data: misc.TData, options?: opts.IAppendFileOptions | string): void;
+  readdirSync(path: PathLike, options?: opts.IReaddirOptions | string): misc.TDataOut[] | misc.IDirent[];
+  readlinkSync(path: PathLike, options?: opts.IOptions): misc.TDataOut;
+  fdatasyncSync(fd: number): void;
+  ftruncateSync(fd: number, len?: number): void;
+  truncateSync(id: misc.TFileId, len?: number): void;
+  futimesSync(fd: number, atime: misc.TTime, mtime: misc.TTime): void;
+  utimesSync(path: PathLike, atime: misc.TTime, mtime: misc.TTime): void;
+  mkdirSync(path: PathLike, options: opts.IMkdirOptions & { recursive: true }): string | undefined;
+  mkdirSync(path: PathLike, options?: misc.TMode | (opts.IMkdirOptions & { recursive?: false })): void;
+  mkdirSync(path: PathLike, options?: misc.TMode | opts.IMkdirOptions): string | undefined;
+  mkdirpSync(path: PathLike, mode?: misc.TMode): void;
+  mkdtempSync(prefix: string, options?: opts.IOptions): misc.TDataOut;
+  rmdirSync(path: PathLike, options?: opts.IRmdirOptions): void;
+  rmSync(path: PathLike, options?: opts.IRmOptions): void;
+  fchmodSync(fd: number, mode: misc.TMode): void;
+  chmodSync(path: PathLike, mode: misc.TMode): void;
+  lchmodSync(path: PathLike, mode: misc.TMode): void;
+  fchownSync(fd: number, uid: number, gid: number): void;
+  chownSync(path: PathLike, uid: number, gid: number): void;
+  lchownSync(path: PathLike, uid: number, gid: number): void;
+}