registry / AI-agent control-surface risk / @chemx/create-chemx / 26.9.17-1100

@chemx/create-chemx@26.9.17-1100

Chemical X Protocol: Private drop-in architecture starter kit and capsule generator

AI Security Review

scanned 11d ago · by lpm-firewall-ai

The package's postinstall hook automatically writes agent MCP configuration for the consumer project and can alter a user-level Antigravity configuration without an explicit setup choice. This meets the policy for blocking unconsented install-time mutation of agent control surfaces.

Static reason

High-risk behavior combination matched malicious policy.; previous stored version diff introduced dangerous source

Trigger

npm install runs the package's postinstall hook.

Impact

Consumer agent tools can discover and launch the package's MCP server without the user explicitly choosing the setup operation.

Mechanism

The hook calls installAllMcpConfigs for the consumer directory without prompting. That function writes project MCP configurations and may write a user-level Antigravity MCP configuration.

Policy narrative

The manifest invokes a postinstall script. That script targets the installing project and automatically registers the package's MCP server in Cursor and VS Code configurations; if Antigravity's config directory exists, it also writes a global server registration. The resulting configuration launches ChemX through a local entrypoint or npx. This is an unconsented install-time mutation of foreign agent control surfaces.

AI rationale

Evidence

package.jsoncli/postinstall.jscli/mcp/installer.js.cursor/mcp.json.vscode/mcp.json~/.gemini/config/mcp_config.json

Decision evidence

public snapshot

AI identified this as a dangerous AI-agent capability at 96.0% confidence with low false-positive risk.

Evidence for policy risk

package.json runs cli/postinstall.js automatically during installation.
The postinstall hook targets INIT_CWD or the current directory and calls installAllMcpConfigs without a consent check.
The installer writes MCP server configuration into project .cursor and .vscode directories, and also targets Antigravity's user-level configuration when present.
The generated server definition launches the ChemX MCP command through a local entrypoint or npx.
The separately exposed AGENTS.md instruction installer is reached through an interactive setup wizard.

Evidence against

The package is presented as an MCP installer, and the generated server entry invokes ChemX's own MCP command.
The interactive installer offers a cancel option for its separately invoked setup flow.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStringsUrlStrings

Source & flagged code

10 flagged

package.jsonView file

Lines 26-66json

26 "scripts",

27 "README.md",

28 "LICENSE",

29 "docs",

30 "assets"

31 ],

32 "exports": {

33 ".": "./cli/index.js",

34 "./audit": "./cli/audit.js",

35 "./build": "./cli/build.js",

36 "./search": "./cli/search.js",

37 "./mcp": "./cli/mcp/index.js",

38 "./reader": "./cli/reader.js",

39 "./patcher": "./cli/patcher.js"

40 },

41 "scripts": {

42 "chemx": "node cli/index.js",

43 "test": "node --test cli/audit/*.spec.js cli/mcp/*.spec.js cli/build/*.spec.js cli/team/*.spec.js cli/*.spec.js",

44 "typecheck": "tsc --noEmit",

45 "publish:both": "node scripts/publish-both.mjs",

46 "postinstall": "node cli/postinstall.js",

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L46

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg · L46

47 "chemx:mcp": "chemx mcp",

48 "chemx:verify": "chemx verify",

49 "chemx:test": "chemx test",

50 "chemx:typecheck": "chemx typecheck"

51 },

52 "dependencies": {

53 "@babel/parser": "^7.29.8",

54 "@babel/traverse": "^7.29.8",

55 "@babel/types": "^7.29.8",

56 "react": "^18.3.1",

57 "react-dom": "^18.3.1"

58 },

59 "devDependencies": {

60 "@types/babel__traverse": "^7.28.0",

61 "@types/node": "^22.20.2",

62 "@types/react": "^18.3.31",

63 "@types/react-dom": "^18.3.7",

64 "typescript": "^5.9.3"

65 }

66}

cli/audit-preflight-git.jsView file

Lines 1-21javascript

1import fs from 'node:fs';

2import { spawnSync } from 'node:child_process';

High

Child Process

Package source references child process execution.

cli/audit-preflight-git.jsView on unpkg · L1

4const SOURCE_FILE_PATTERN = /

cli/terminal.jsView file

Lines 1-30javascript

1import readline from "node:readline";

2import { spawnSync } from "node:child_process";

3import { formatChemicalXGradient, ANSI } from "./theme.js";

5export const openBrowser

cli/license.jsView file

Lines 1-23javascript

1import fs from 'node:fs';

2import path from 'node:path';

3import os from 'node:os';

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

cli/mcp/installer.jsView file

Lines 1-21javascript

1import fs from 'node:fs';

2import path from 'node:path';

3import os from 'node:os';

4import { syncAntigravityMcpSchemas } from './antigravity.js';

cli/scaffold.jsView file

•Runtime or CLI code links a write operation to an explicit external AI-agent control path: udes('--no-interactive') || boolean(process.env.ci) || process.stdout?.istty === false || process.stdin?.istty === false || boolean(process.argv?.some((arg) => arg === '--headless' || arg === '--ci' || arg === '--yes' || arg === '-y')); if (isheadless) { targetname = 'my-molecular-app'; } else { targetname = hasgum() ? guminput('project directory name:', 'my-molecular-app') : await promptquestion('project directory name [my-molecular-app]: '); } } const finaldirname = targetname.trim() || 'my-molecular-app'; const targetdir = path.resolve(process.cwd(), finaldirname); const direxists = fs.existssync(targetdir); const isdirno

High

External Ai Agent Control Surface Mutation

Runtime or CLI source writes behavior-bearing configuration into a user or project AI-agent control surface.

cli/scaffold.jsView on unpkg

•Manifest-trigger-reachable source links an external AI-agent control path to a behavior-bearing write operation. s = {}; if (!licensekey) { process.stdout.write( '\n\x1b[38;2;98;201;255m⚡ chemical x: community edition (free)\x1b[0m\n' + 'the community version is free because you tell us about your project\n' + 'and the app will automatically post your scorecard to our github discussions.\n' + 'you get a free plug, we get data to prove chemical x works and brings real value.\n' + 'everybody wins! thank you for supporting our community version.\n\n' ); files = loadlocalblueprintfiles(); iscommunity = true; } else { files = await fetchstarterkitfiles(licensekey); } let targetname = projectname; if (!targetname) { const isheadle

High

Trigger Reachable External Ai Agent Control Surface Mutation

Manifest-trigger-reachable source writes behavior-bearing configuration into a user or project AI-agent control surface.

scripts/pre-commit.shView file

•path = scripts/pre-commit.sh kind = build_helper sizeBytes = 5175 magicHex = [redacted]

Medium

Ships Build Helper

Package ships non-JavaScript build or shell helper files.

scripts/pre-commit.shView on unpkg

Source & flagged code

10 flagged · loading source

package.jsonView file

•scripts.postinstall = node cli/postinstall.js

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node cli/postinstall.js

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

cli/audit-preflight-git.jsView file

1import fs from 'node:fs'; L2: import { spawnSync } from 'node:child_process'; L3:

High

Child Process

Package source references child process execution.

cli/audit-preflight-git.jsView on unpkg · L1

Findings

1 Critical7 High5 Medium4 Low

CriticalAi Agent Control Hijackcli/mcp/installer.js

HighInstall Time Lifecycle Scriptspackage.json

HighChild Processcli/audit-preflight-git.js

HighShellcli/terminal.js

HighSame File Env Network Executioncli/license.js

HighExternal Ai Agent Control Surface Mutationcli/scaffold.js

HighTrigger Reachable External Ai Agent Control Surface Mutationcli/scaffold.js

HighPrevious Version Dangerous Deltacli/license.js

MediumAmbiguous Install Lifecycle Scriptpackage.json

MediumNetwork

MediumEnvironment Vars

MediumShips Build Helperscripts/pre-commit.sh

Affected versions and remediation

This report applies to @chemx/create-chemx@26.9.17-1100.

See all versions of @chemx/create-chemx for other recorded verdicts.

Avoid installing @chemx/create-chemx@26.9.17-1100. Remove it from direct dependencies and check your lockfile for transitive copies.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.
If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.

Evidence last updated: 2026-10-12 06:44:07.746Z (UTC).

Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Related packages

More from @chemx

Other AI-agent control-surface risk packages

Behavioral surface

Related packages

More from @chemx

Other AI-agent control-surface risk packages

Source & flagged code