registry / AI-agent control-surface risk / @chemx/starter-kit / 26.9.17-309

@chemx/starter-kit@26.9.17-309

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 automatic postinstall mutates consumer AI-agent configuration without a consent gate, establishing an active install-time control-surface change. This meets the blocking policy for unconsented postinstall mutation; the inspected evidence does not establish credential theft.

Static reason

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

Trigger

Installing the package through npm triggers its postinstall lifecycle script.

Impact

The package changes agent configuration without an explicit setup choice, causing supported agents to expose the package's MCP server after configuration reload or restart.

Mechanism

The hook calls the MCP installer, which writes Cursor and VS Code project configuration and may update an existing Gemini global configuration to launch the Chemical X CLI.

Policy narrative

The npm postinstall hook immediately registers the package's MCP server in project agent configuration, and may also alter an existing Gemini configuration. This is an unconsented install-time change to an AI-agent control surface. The inspected code does not establish credential theft or data exfiltration.

AI rationale

Evidence

package.jsoncli/postinstall.jscli/mcp/installer.jscli/mcp/installer.spec.js

Decision evidence

public snapshot

AI identified this as a dangerous AI-agent capability at 97.0% confidence with low false-positive risk.

Evidence for policy risk

package.json runs cli/postinstall.js automatically after installation.
The postinstall uses the consumer install directory and calls installAllMcpConfigs without asking for consent.
The installer writes MCP server configuration into project .cursor/mcp.json and .vscode/mcp.json.
The configured server launches the local CLI or runs npx -y chemx mcp; an existing Gemini config also receives a global MCP entry.
The targeted agent configuration locations contain MCP installer behavior and tests confirming the Cursor entry is created.

Evidence against

The package self-install case is skipped, and errors are caught without failing installation.
The integration configures a named Chemical X MCP server; source evidence does not show credential collection or exfiltration.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStringsUrlStrings

Source & flagged code

10 flagged

package.jsonView file

Lines 35-74json

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

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

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

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

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

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

41 "./patcher": "./cli/patcher.js"

42 },

43 "scripts": {

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

45 "test": "node --test cli/audit/*.spec.js cli/mcp/*.spec.js cli/*.spec.js",

46 "typecheck": "tsc --noEmit",

47 "create-capsule": "node cli/index.js",

48 "audit": "node cli/index.js audit",

49 "ci:audit": "node cli/index.js audit --ci --dir=cli",

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

51 "q": "chemx search",

52 "search": "chemx search",

53 "mcp": "node cli/index.js mcp",

54 "install-mcp": "node cli/index.js install-mcp",

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

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L55

Medium

Ambiguous Install Lifecycle Script

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

package.jsonView on unpkg · L55

56 "read": "node cli/index.js read",

57 "patch": "node cli/index.js patch"

58 },

59 "dependencies": {

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

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

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

63 "react": "^18.3.1",

64 "react-dom": "^18.3.1"

65 },

66 "devDependencies": {

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

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

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

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

71 "typescript": "^5.9.3"

72 }

73}

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';

5const SERVER_KEY =

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/starter-kit@26.9.17-309.

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

Avoid installing @chemx/starter-kit@26.9.17-309. 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 06:19:21.408Z (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

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Behavioral surface

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Source & flagged code