halfcycle@0.3.26
Your coding agents are the engineers. Halfcycle is the rest of the team: product owner, architect, planner and independent reviewer for Claude Code.
AI Security Review
scanned 28d ago · by lpm-firewall-aiThe package has no npm install hook, and the agent setup is reached through an explicit CLI command with allowlisted project writes. The first-party Claude Code hook integration remains a warning-level capability, not evidence of a confirmed attack.
Static reason
No blocking static signals were detected.
Trigger
A user runs the package's CLI install command for a repository.
Impact
The repository's Claude Code sessions may invoke the guard runner. No credential theft or other concrete attack was established.
Mechanism
The installer writes designated Claude Code commands and hooks, then configures a hook to invoke the bundled runner; project writes pass through a path allowlist.
AI rationale
The package has no npm install hook, and the agent setup is reached through an explicit CLI command with allowlisted project writes. The first-party Claude Code hook integration remains a warning-level capability, not evidence of a confirmed attack.
Evidence
dist/bin.jsbin/bin.bundle.mjs.claude/commands.claude/hooks.claude/settings.json.halfcycle
Network endpoints1
guard.halfcycle.ai
Decision evidence
public snapshotAI called this Suspicious at 86.0% confidence as Dangerous Capability with medium false-positive risk.
Evidence for warning
- The manifest exposes a CLI but defines no npm install lifecycle hook.
- Running the CLI install command writes Claude Code commands and hooks, including a command hook that launches the bundled guard runner.
- Project writes are checked against a path allowlist.
- The bundled runner reads its guard service URL and token from configuration and environment variables.
Evidence against
- The configuration setup is invoked through the CLI; no automatic npm install trigger was found.
- The CLI limits writes to designated project paths, and the bundled runner obtains guard credentials from its configured service context.
Behavioral surface
ChildProcessCryptoEnvironmentVarsFilesystemNetworkShell
HighEntropyStringsUrlStrings
Source & flagged code
6 flaggedbin/bin.bundle.mjsView file
15448// dist/git.js
L15449: import { spawnSync } from "node:child_process";
L15450: import { readFileSync } from "node:fs";
High
Child Process
Package source references child process execution.
bin/bin.bundle.mjsView on unpkg · L15448dist/bin.jsView file
1860var MCP_HEADERS_HELPER_REL = ".halfcycle/mcp-headers.sh";
L1861: var MCP_HEADERS_HELPER_COMMAND = `/bin/sh -c 'd=$(pwd); while [ ! -f "$d/${MCP_HEADERS_HELPER_REL}" ] && [ "$d" != / ]; do d=$(dirname "$d"); done; [ -f "$d/${MCP_HEADERS_HELPER_RE...
L1862: var GENERATED_MCP_HEADERS_HEADER = "# Halfcycle MCP connection headers \u2014 generated by";
High
2311// dist/control-origin.js
L2312: var DEFAULT_CONTROL_ORIGIN = "https://control.halfcycle.ai";
L2313: function resolveControlOrigin(env = process.env) {
L2314: const configured = env["HALFCYCLE_SERVICE_URL"]?.trim();
...
L2323: // dist/device-signin.js
L2324: import { spawn } from "node:child_process";
L2325: import { platform as platform3 } from "node:os";
Findings
4 High4 Medium4 Low
HighChild Processbin/bin.bundle.mjs
HighShelldist/bin.js
HighSame File Env Network Executiondist/bin.js
HighTrigger Reachable External Post Callbackdist/bin.js
MediumNetwork
MediumEnvironment Vars
MediumSuspicious Lifecycle Evidencepackage.json
MediumAi Review Evidencedist/bin.js
LowScripts Present
LowFilesystem
LowHigh Entropy Strings
LowUrl Strings
Affected versions and remediation
This report applies to halfcycle@0.3.26.
See all versions of halfcycle for other recorded verdicts.
- Review the evidence and your use of halfcycle@0.3.26 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: .
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