registry / @hetalhouse/fiddle / 0.2.5

@hetalhouse/fiddle@0.2.5

Scaffold and run throwaway framework sandboxes ('fiddles') — delegates to official scaffolders (Vite, Angular CLI…) where they exist, ships curated templates where they don't.

AI Security Review

scanned 2h ago · by lpm-firewall-ai

No confirmed malicious attack surface. Process execution and project-file writes are user-invoked CLI behavior for scaffolding, running, publishing, and optional local screenshots.

Static reason

One or more suspicious static signals were detected.

Trigger

Explicit `fiddle` CLI commands such as create, fork, start, build, preview, or publish.

Impact

May modify or execute commands inside the user-selected fiddle and configured publish repository; no unconsented install-time action was found.

Mechanism

User-directed local project scaffolding, shell execution, and localhost previewing.

Rationale

The flagged primitives implement the documented interactive CLI workflow and are not activated during package installation or import. Source inspection found no concrete malicious chain or foreign AI-agent control-surface mutation.

Evidence

package.jsondist/cli.jsdist/core.jsdist/config.jsdist/screenshot.jsdist/defaults.js~/.fiddle/config.json<fiddle>/CLAUDE.md<fiddle>/README.md<fiddle>/.fiddle.json<publishRepo>/index.html<publishRepo>/manifest.json

Decision evidence

public snapshot

AI called this Clean at 97.0% confidence as Benign with low false-positive risk.

Evidence for block

`dist/core.js` runs shell commands only through explicit CLI workflows.
`dist/core.js` writes `CLAUDE.md` into user-selected fiddle projects.
`dist/screenshot.js` dynamically loads Playwright and starts local dev servers on loopback.

Evidence against

`package.json` has no preinstall, install, or postinstall hook; `prepublishOnly` only builds.
`dist/cli.js` registers user-invoked scaffold, install, build, preview, and publish commands.
`dist/screenshot.js` uses only localhost URLs for optional screenshots.
No credential harvesting, external exfiltration, eval/vm, remote payload loading, or stealth persistence was found.
`CLAUDE.md` content in `dist/defaults.js` is benign project guidance and is written only by explicit commands.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStringsUrlStrings

ManifestNo manifest risk signals triggered.

scanned 16 file(s), 99.6 KB of source, external domains: github.com

Source & flagged code

3 flagged

dist/core.jsView file

Lines 1-42javascript

1import { spawn } from 'node:child_process';

2import fs from 'node:fs';

High

Child Process

Package source references child process execution.

dist/core.jsView on unpkg · L1

3import path from 'node:path';

4import { fileURLToPath } from 'node:url';

5import { REGISTRY } from './registry.js';

6import { loadConfig, resolveHome } from './config.js';

7import { PLAYWRIGHT_CONFIG, SMOKE_SPEC, claudeMd, readmeMd } from './defaults.js';

8/** fiddle-0011-PlanetTween → "Planet Tween" — display title for a fresh README. */

9export function humanizeName(dirName) {

10 return dirName

11 .replace(/^fiddle-\d+-/, '')

12 .replace(/[-_]+/g, ' ')

13 .replace(/([A-Z]+)([A-Z][a-z])/g, '$1 $2')

14 .replace(/([a-z\d])([A-Z])/g, '$1 $2')

15 .replace(/\s+/g, ' ')

16 .trim();

17}

18const HERE = path.dirname(fileURLToPath(import.meta.url));

19export const TEMPLATES_DIR = path.resolve(HERE, '../templates');

20/** Run a shell command string in `cwd`, inheriting stdio. Rejects on non-zero exit. */

21export function runShell(cmd, cwd) {

22 return new Promise((resolve, reject) => {

23 const child = spawn(cmd, { cwd, stdio: 'inherit', shell: true });

24 child.on('error', reject);

High

Shell

Package source references shell execution.

dist/core.jsView on unpkg · L22

25 child.on('close', (code) => code === 0 ? resolve() : reject(new Error(`\`${cmd}\` exited with code ${code}`)));

26 });

27}

28/**

29 * Best-effort shell: resolves true on a clean exit, false on error / non-zero /

30 * timeout. Never throws, never inherits stdio. For publishing an archive where

31 * a decade-old `npm install` may fail or hang — we skip it and move on.

32 */

33export function tryShell(cmd, cwd, timeoutMs = 120_000) {

34 return new Promise((resolve) => {

35 const child = spawn(cmd, { cwd, stdio: 'ignore', shell: true, detached: true });

36 const timer = setTimeout(() => {

37 try {

38 process.kill(-child.pid, 'SIGKILL'); // kill the whole process group (npm children)

39 }

40 catch {

41 child.kill('SIGKILL');

42 }

dist/cli.jsView file

Lines 1-23javascript

1#!/usr/bin/env node

2import { Command } from 'commander';

3import { createInterface } from 'node:readline/promises';

4import { execSync } from 'node:child_process';

5import fs from 'node:fs';

6import os from 'node:os'

Source & flagged code

3 flagged · loading source

dist/core.jsView file

1import { spawn } from 'node:child_process'; L2: import fs from 'node:fs';

High

Child Process

Package source references child process execution.

dist/core.jsView on unpkg · L1

22return new Promise((resolve, reject) => { L23: const child = spawn(cmd, { cwd, stdio: 'inherit', shell: true }); L24: child.on('error', reject);

High

Shell

Package source references shell execution.

dist/core.jsView on unpkg · L22

dist/cli.jsView file

3Cross-file remote execution chain: dist/cli.js spawns dist/portfolio.js; helper contains network access plus dynamic code execution. L3: import { createInterface } from 'node:readline/promises'; L4: import { execSync } from 'node:child_process'; L5: import fs from 'node:fs'; ... L23: async function prompt(q) { L24: const rl = createInterface({ input: process.stdin, output: process.stdout }); L25: const a = (await rl.question(c.amber(` ${q} `))).trim(); ... L31: try { L32: execSync(process.platform === 'win32' ? `where ${bin}` : `command -v ${bin}`, { stdio: 'ignore' }); L33: return true; ... L125: try { L126: await runShell('npx --yes playwright install chromium', process.cwd()); L127: console.log(` ${c.green('✓')} Chromium installed`);

High

Cross File Remote Execution Context

Source spawns a local helper that also contains network and dynamic execution context; review data flow before blocking.

dist/cli.jsView on unpkg · L3

Findings

3 High2 Medium5 Low

HighChild Processdist/core.js

HighShelldist/core.js

HighCross File Remote Execution Contextdist/cli.js

MediumNetwork

MediumEnvironment Vars

LowNon Install Lifecycle Scripts

LowScripts Present

LowFilesystem

LowHigh Entropy Strings

LowUrl Strings

Source & flagged code

3 flagged

dist/core.jsView file

Lines 1-42javascript

1import { spawn } from 'node:child_process';

2import fs from 'node:fs';

High

Child Process

Package source references child process execution.

dist/core.jsView on unpkg · L1

3import path from 'node:path';

4import { fileURLToPath } from 'node:url';

5import { REGISTRY } from './registry.js';

6import { loadConfig, resolveHome } from './config.js';

7import { PLAYWRIGHT_CONFIG, SMOKE_SPEC, claudeMd, readmeMd } from './defaults.js';

8/** fiddle-0011-PlanetTween → "Planet Tween" — display title for a fresh README. */

9export function humanizeName(dirName) {

10 return dirName

11 .replace(/^fiddle-\d+-/, '')

12 .replace(/[-_]+/g, ' ')

13 .replace(/([A-Z]+)([A-Z][a-z])/g, '$1 $2')

14 .replace(/([a-z\d])([A-Z])/g, '$1 $2')

15 .replace(/\s+/g, ' ')

16 .trim();

17}

18const HERE = path.dirname(fileURLToPath(import.meta.url));

19export const TEMPLATES_DIR = path.resolve(HERE, '../templates');

20/** Run a shell command string in `cwd`, inheriting stdio. Rejects on non-zero exit. */

21export function runShell(cmd, cwd) {

22 return new Promise((resolve, reject) => {

23 const child = spawn(cmd, { cwd, stdio: 'inherit', shell: true });

24 child.on('error', reject);

High

Shell

Package source references shell execution.

dist/core.jsView on unpkg · L22

25 child.on('close', (code) => code === 0 ? resolve() : reject(new Error(`\`${cmd}\` exited with code ${code}`)));

26 });

27}

28/**

29 * Best-effort shell: resolves true on a clean exit, false on error / non-zero /

30 * timeout. Never throws, never inherits stdio. For publishing an archive where

31 * a decade-old `npm install` may fail or hang — we skip it and move on.

32 */

33export function tryShell(cmd, cwd, timeoutMs = 120_000) {

34 return new Promise((resolve) => {

35 const child = spawn(cmd, { cwd, stdio: 'ignore', shell: true, detached: true });

36 const timer = setTimeout(() => {

37 try {

38 process.kill(-child.pid, 'SIGKILL'); // kill the whole process group (npm children)

39 }

40 catch {

41 child.kill('SIGKILL');

42 }

dist/cli.jsView file

Lines 1-23javascript

1#!/usr/bin/env node

2import { Command } from 'commander';

3import { createInterface } from 'node:readline/promises';

4import { execSync } from 'node:child_process';

5import fs from 'node:fs';

6import os from 'node:os'