halfcycle@0.4.4
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 17d ago · by lpm-firewall-aiThe manifest has no npm lifecycle hook, and the agent configuration changes occur through the explicit CLI setup. Credentialed requests target the configured Halfcycle service or an API caller’s supplied endpoint; the bounded code excerpts are part of the documented check workflow, so the inspected signals do not establish malicious behavior.
Static reason
One or more suspicious static signals were detected.; previous stored version diff introduced dangerous source
Trigger
Running the CLI’s install command configures the project; configured Claude hook events later invoke checks.
Impact
These behaviors enable the advertised code-check workflow. No malicious effect or unconsented install-time activation was established.
Mechanism
The installer merges project-local Claude hooks and deny rules and registers Halfcycle’s MCP service. Guard checks send capped change metadata and optional source excerpts to the configured Halfcycle service.
AI rationale
The manifest has no npm lifecycle hook, and the agent configuration changes occur through the explicit CLI setup. Credentialed requests target the configured Halfcycle service or an API caller’s supplied endpoint; the bounded code excerpts are part of the documented check workflow, so the inspected signals do not establish malicious behavior.
Evidence
.claude/settings.json.claude/hooks/guard-runner.sh.mcp.json.halfcycle/bin/bin.bundle.mjs
Network endpoints2
control.halfcycle.aiguard.halfcycle.ai
Decision evidence
public snapshotAI called this Clean at 93.0% confidence as Benign with low false-positive risk.
Evidence for AI clean decision
- package.json exposes a CLI and import entrypoint, with build and test scripts but no npm install lifecycle hook.
- The CLI’s explicit install path configures project-local Claude hooks and deny rules, then registers Halfcycle’s MCP service; the guarded paths are local to the project.
- Runtime bearer requests use the service URL or an endpoint supplied by the API caller, and the CLI defaults to Halfcycle’s control service.
- Guard checks can send capped source excerpts to Halfcycle; the README describes this data flow as part of the checks and ties it to terms accepted at sign-in.
Evidence against
- Guard checks transmit limited source excerpts by default unless explicitly disabled.
Behavioral surface
ChildProcessCryptoEnvironmentVarsEvalFilesystemNetwork
HighEntropyStringsUrlStrings
Source & flagged code
9 flaggedbin/bin.bundle.mjsView file
15715// dist/git.js
L15716: import { spawnSync } from "node:child_process";
L15717: import { existsSync, readFileSync } from "node:fs";
High
Child Process
Package source references child process execution.
bin/bin.bundle.mjsView on unpkg · L15715dist/cli.jsView file
•matchType = previous_version_dangerous_delta
matchedPackage = halfcycle@0.4.3
matchedIdentity = npm:aGFsZmN5Y2xl:0.4.3
similarity = 0.600
summary = stored previous version shares package body but lacks this dangerous source file
Critical
Previous Version Dangerous Delta
This package version adds a dangerous source file absent from the previous stored version; route for source-aware review.
dist/cli.jsView on unpkg3216// dist/control-origin.js
L3217: var DEFAULT_CONTROL_ORIGIN = "https://control.halfcycle.ai";
L3218: function resolveControlOrigin(env = process.env) {
L3219: const configured = env["HALFCYCLE_SERVICE_URL"]?.trim();
...
L3228: // dist/device-signin.js
L3229: import { spawn } from "node:child_process";
L3230: import { platform as platform3 } from "node:os";
Findings
1 Critical8 High3 Medium5 Low
CriticalPrevious Version Dangerous Deltadist/cli.js
HighChild Processbin/bin.bundle.mjs
HighSame File Env Network Executiondist/cli.js
HighCommand Output Exfiltrationdist/cli.js
HighSandbox Evasion Gated Capabilitydist/cli.js
HighCross File Remote Execution Contextdist/cli.js
HighTrigger Reachable Command Output Exfiltrationdist/cli.js
HighRuntime Package Installdist/cli.js
HighSemantic Analysis Limiteddist/index.js
MediumNetwork
MediumEnvironment Vars
MediumStructural Risk Force Deep Review
LowScripts Present
Affected versions and remediation
This report applies to halfcycle@0.4.4.
See all versions of halfcycle for other recorded verdicts.
- Review the evidence and your use of halfcycle@0.4.4 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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