veryfront/fs

Runtime boundary

veryfront/fs uses the native process filesystem selected for Deno, Node, or Bun. It does not delegate to the runtime.get().fs adapter. Custom adapters configured with runtime.set() affect adapter-consuming APIs, not these compatibility functions. veryfront/fs does not add a project-root sandbox, block .env or other secret-file names, or validate paths from untrusted input. Relative paths resolve from cwd(). Absolute paths and .. segments can reach any location that the runtime permits. Runtime permissions remain the outer boundary. Hosted project secrets are supplied through request-owned environment data rather than .env files. Isolated Pages route ctx.fs is a separate, read-only, project-confined capability. Those protections do not change the contract of veryfront/fs. Canonicalize a trusted root and candidate with realPath, then use validateLexicalPath from veryfront/security before reading a user-influenced path. Canonicalization follows existing symlinks before the containment check. Path admission is not an operating-system sandbox. The trusted root must not be writable by untrusted or project code while a validated path is in use. Otherwise, concurrent filesystem changes can create a time-of-check/time-of-use race between validation and reading.

Import

import { exists, join, mkdir, readTextFile, resolve, writeTextFile } from "veryfront/fs";

Examples

File operations

import { exists, mkdir, readTextFile, writeTextFile } from "veryfront/fs";

const data = JSON.parse(await readTextFile("./data/config.json"));
await mkdir("./output", { recursive: true });
await writeTextFile("./output/result.json", JSON.stringify(data));

Path utilities

import { basename, dirname, extname, join, resolve } from "veryfront/fs";

const filePath = join("src", "pages", "index.tsx");
const dir = dirname(filePath); // "src/pages"

Working directory

import { cwd, resolve } from "veryfront/fs";

const configPath = resolve(cwd(), "veryfront.config.ts");

Confine an untrusted path

import { cwd, readTextFile, realPath, resolve } from "veryfront/fs";
import { validateLexicalPath } from "veryfront/security";

const publicFilesDir = await realPath(resolve(cwd(), "public-data"));

export async function readPublicFile(requestedPath: string): Promise<string> {
  const candidate = resolve(publicFilesDir, requestedPath);
  const canonicalPath = await realPath(candidate);
  const admitted = validateLexicalPath(canonicalPath, {
    baseDir: publicFilesDir,
    allowAbsolute: true,
  });
  if (!admitted.valid || !admitted.canonicalPath) {
    throw new Error("Invalid path");
  }
  return await readTextFile(admitted.canonicalPath);
}

Exports

Functions

Name	Description	Source
`basename`	Return the last path segment.	source
`createFileSystem`	Create the runtime-native filesystem implementation.	source
`cwd`	Return the current working directory.	source
`dirname`	Return the parent directory path.	source
`exists`	Return false for a missing path and propagate every other filesystem error.	source
`extname`	Return the file extension for a path.	source
`isFileSnapshotChangedError`	Return whether a value is a framework-created file snapshot change error.	source
`isNotFoundError`		source
`join`	Join and normalize path segments using their detected path flavor.	source
`lstat`	Read file metadata without following a terminal symbolic link.	source
`mkdir`	Create a directory.	source
`readDir`	Read directory entries.	source
`readTextFile`	Read a file as text.	source
`realPath`	Resolve a path to its canonical absolute form, following symlinks. Throws if the path does not exist. Useful for containment checks where a symlink could otherwise escape an intended directory.	source
`remove`	Remove a file or directory, rejecting when the path does not exist.	source
`resolve`	Resolve path segments to an absolute, normalized path.	source
`writeTextFile`	Write text to a file.	source

Classes

Name	Description	Source
`FileSnapshotChangedError`	Error raised when a file changes while a stable snapshot is being read.	source

Types

Name	Description	Source
`FileSystem`	Runtime-neutral filesystem contract.	source

Getting Started

Concepts

Guides

API Reference

Runtime boundary

Import

Examples

File operations

Path utilities

Working directory

Confine an untrusted path

Exports

Functions

Classes

Types

​Runtime boundary

​Import

​Examples

​File operations

​Path utilities

​Working directory

​Confine an untrusted path

​Exports

​Functions

​Classes

​Types

Runtime boundary

Import

Examples

File operations

Path utilities

Working directory

Confine an untrusted path

Exports

Functions

Classes

Types