registry / @chemx/starter-kit / 26.9.20-369

@chemx/starter-kit@26.9.20-369

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

AI Security Review

scanned 11d ago · by lpm-firewall-ai

The automatic postinstall mutation of project-local agent configuration is a real lifecycle risk. Because it registers this package’s own MCP server and no separate concrete attack behavior was established, classify it as suspicious and warn rather than block.

Static reason

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

Trigger

Installing the package through npm runs its postinstall hook.

Impact

The project’s supported AI clients can load the package-owned MCP server; no credential theft or remote payload execution was established from the inspected path.

Mechanism

The hook calls the MCP installer for the consumer project, which writes a Chemical X server entry into .cursor/mcp.json and .vscode/mcp.json without an interactive consent step.

AI rationale

Evidence

package.jsoncli/postinstall.jscli/mcp/installer.js.cursor/mcp.json.vscode/mcp.json

Decision evidence

public snapshot

AI called this Suspicious at 89.0% confidence as Dangerous Capability with medium false-positive risk.

Evidence for warning

package.json defines a postinstall hook that runs cli/postinstall.js.
The hook targets the installing project and calls installAllMcpConfigs without a consent check.
The MCP installer writes a package-owned server entry into the project’s Cursor MCP configuration.
The installer also writes the server entry into the project’s VS Code MCP configuration.
When no local starter-kit executable is found, the configured server command is npx -y chemx mcp.
The source also contains separate project setup behavior: a scaffold copies AGENTS.md only when the destination does not already exist.

Evidence against

The registered MCP server is the package’s own Chemical X service; the inspected code does not show credential collection, exfiltration, destructive behavior, or a remote payload being fetched and executed by the postinstall hook.
The package’s separate interactive installer presents MCP setup as a selectable option, but that prompt does not guard the postinstall path.

Behavioral surface

Source

ChildProcessEnvironmentVars

Source & flagged code

11 flagged

package.jsonView file

Lines 29-69json

29 "README.md",

30 "LICENSE",

31 "docs",

32 "assets"

33 ],

34 "exports": {

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 "./errors": "./cli/errors/index.js"

43 },

44 "scripts": {

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

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

47 "typecheck": "tsc --noEmit",

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

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

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L49

Medium

Ambiguous Install Lifecycle Script

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

package.jsonView on unpkg · L49

50 "chemx:mcp": "chemx mcp",

51 "chemx:verify": "chemx verify",

52 "chemx:test": "chemx test",

53 "chemx:typecheck": "chemx typecheck"

54 },

55 "dependencies": {

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

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

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

59 "react": "^18.3.1",

60 "react-dom": "^18.3.1"

61 },

62 "devDependencies": {

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

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

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

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

67 "chemx": "26.9.17-1100",

68 "typescript": "^5.9.3"

69 }

cli/errors/errors.spec.jsView file

Lines 7-47javascript

7 maskSensitiveTokens,

8 normalizeHomePath,

9 sanitizeText,

10 sanitizeStackTrace

11} from './sanitizer.js';

12import {

13 buildIssueTitle,

14 buildIssueBody,

15 buildIssueWebUrl,

16 formatIssueContent

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/build/executor.jsView file

Lines 1-31javascript

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

3export const executeBuild = (command, cwd = process.cwd(), options = {})

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

•Manifest-trigger-reachable source links an external AI-agent control path to a behavior-bearing write operation. 'no background telemetry is exfiltrated without your explicit consent.\n' + 'thank you for supporting chemical x!\n\n' ); files = loadlocalblueprintfiles(); iscommunity = true; } else { files = await fetchstarterkitfiles(licensekey); } let targetname = projectname; if (!targetname) { const isheadless = rawargs.includes('--headless') || rawargs.includes('--yes') || rawargs.includes('-y') || rawargs.includes('--ci') || rawargs.includes('--non-interactive') || rawargs.includes('--no-interactive') || boolean(process.env.ci) || process.stdout?.istty === false || process.stdin?.istty === false ||

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.

cli/scaffold.jsView on unpkg

scripts/pre-commit.shView file

•path = scripts/pre-commit.sh kind = build_helper sizeBytes = 5174 magicHex = [redacted]

Medium

Ships Build Helper

Package ships non-JavaScript build or shell helper files.

scripts/pre-commit.shView on unpkg

Source & flagged code

11 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/errors/errors.spec.jsView file

27patternName = github_pat severity = critical line = 27

Critical

Critical Secret

Package contains a critical-looking secret pattern.

cli/errors/errors.spec.jsView on unpkg · L27

Findings

3 Critical6 High5 Medium4 Low

CriticalCritical Secretcli/errors/errors.spec.js

CriticalAi Agent Control Hijackcli/mcp/installer.js

CriticalSecret Patterncli/errors/errors.spec.js

HighInstall Time Lifecycle Scriptspackage.json

HighChild Processcli/audit-preflight-git.js

HighShellcli/build/executor.js

HighSame File Env Network Executioncli/license.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

Affected versions and remediation

This report applies to @chemx/starter-kit@26.9.20-369.

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

Review the evidence and your use of @chemx/starter-kit@26.9.20-369 before allowing it. Restrict the permissions described in this report.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.

Evidence last updated: 2026-10-12 06:20:54.913Z (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

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Behavioral surface

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Source & flagged code