registry / AI-agent control-surface risk / @chemx/starter-kit / 26.9.28-1234

@chemx/starter-kit@26.9.28-1234

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

AI Security Review

scanned 11d ago · by lpm-firewall-ai

The postinstall hook automatically mutates consumer and potentially user-level AI-agent control configuration by adding an MCP server. This meets the policy for blocking unconsented install-time agent control-surface mutation.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

Installing the package with npm in a consumer project.

Impact

An MCP server is added to consumer or user-level agent configuration and can be launched by those agent clients.

Mechanism

The postinstall hook calls the MCP installer for the consumer directory. It writes Cursor and VS Code MCP configuration and can write the user's Antigravity MCP configuration when that directory exists; the server may be launched through npm exec.

Policy narrative

During npm installation, the package's postinstall hook invokes its MCP installer against the consumer directory. The installer writes a Chemical X server entry into Cursor and VS Code configuration and may also update the user's Antigravity configuration. This makes an agent integration active without a separate user-invoked setup step.

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 95.0% confidence with low false-positive risk.

Evidence for policy risk

The package manifest runs cli/postinstall.js during installation.
That hook targets the consumer directory and automatically invokes the MCP configuration installer.
The installer writes MCP server configuration into consumer .cursor/mcp.json and .vscode/mcp.json files.
When an Antigravity config directory exists, the installer also writes its MCP configuration under the user's home directory.
The configured server command can use npm exec to run chemx mcp.

Evidence against

The MCP installer merges the named server entry into existing configuration rather than replacing the full file.
The agent-steering changes in cli/installer.js and cli/pillars-wizard.js are reached through installer or wizard flows, not the postinstall hook. The automatic MCP configuration mutation remains.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStrings

Source & flagged code

11 flagged

package.jsonView file

Lines 35-75json

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 "bench": "node benchmarks/run-benchmark.mjs",

47 "ui": "node cli/index.js ui",

48 "dev:ui": "node cli/index.js ui --dev",

49 "dev:ui:watch": "node --watch --watch-path=cli cli/index.js ui --dev",

50 "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",

51 "check:frameworks": "node scripts/check-framework-generation.mjs",

52 "prepublishOnly": "node scripts/check-framework-generation.mjs",

53 "typecheck": "tsc --noEmit",

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

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 "chemx:mcp": "chemx mcp",

57 "chemx:verify": "chemx verify",

58 "chemx:test": "chemx test",

59 "chemx:typecheck": "chemx typecheck"

60 },

61 "dependencies": {

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

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

64 "@babel/types": "^7.29.8"

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 "chemx": "26.9.20-408",

72 "react": "^18.3.1",

73 "react-dom": "^18.3.1",

74 "typescript": "^5.9.3"

75 }

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/pillars-wizard.jsView file

•Manifest-trigger-reachable source links an external AI-agent control path to a behavior-bearing write operation. st pick = usegum ? gumchoose(choices, 'select architectural pillars configuration') : await promptquestion('select pillars: [1=recommended, 2=strict, 3=custom, 4=minimal, 5=none] (default: 1): '); if (pick && (pick.startswith('2.') || pick === '2')) { selectedpresetkey = 'strict'; selectedpillarids = [...pillar_presets.strict.pillars]; } else if (pick && (pick.startswith('3.') || pick === '3')) { selectedpresetkey = 'custom'; for (const pillar of pillars) { const defaultchoice = pillar_presets.recommended.pillars.includes(pillar.id) ? 'y/n' : 'y/n'; const isdefaultyes = defaultchoice === 'y/n'; const answer = a

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/pillars-wizard.jsView on unpkg

scripts/pre-commit.shView file

•path = scripts/pre-commit.sh kind = build_helper sizeBytes = 8215 magicHex = [redacted]

Medium

Ships Build Helper

Package ships non-JavaScript build or shell helper files.

scripts/pre-commit.shView on unpkg

cli/verify-lint.js#virtual:normalized:round1View file

•stage = ast_semantic_analysis; reason = ast_parse_error; limitedFiles = 1

High

Semantic Analysis Limited

A bounded semantic-analysis stage reached its safety limit; remaining detectors completed, but this package requires AI review.

cli/verify-lint.js#virtual:normalized:round1View 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 Medium5 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/pillars-wizard.js

HighSemantic Analysis Limitedcli/verify-lint.js#virtual:normalized:round1

MediumAmbiguous Install Lifecycle Scriptpackage.json

MediumNetwork

Medium

Affected versions and remediation

This report applies to @chemx/starter-kit@26.9.28-1234.

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

Avoid installing @chemx/starter-kit@26.9.28-1234. 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 06:24:28.622Z (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