A lightweight sandboxing tool for enforcing filesystem and network restrictions on arbitrary processes at the OS level, without requiring a container.
This report presents the forensic synthetic code analysis of anthropic-experimental/sandbox-runtime, a TypeScript project with 4,670 GitHub stars. SynthScan v2.0 examined 41,704 lines of code across 95 source files, recording 99 pattern matches distributed across 8 syntactic categories. The overall adjusted score of 4.1 places this repository in the Likely human-written band.
The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).
Longitudinal tracking requires multiple scan runs. Once this repository is re-scanned after new commits land, this chart will visualise how the synthetic code signal evolves over time — enabling you to detect whether AI authorship is growing, stabilising, or being actively corrected by human engineers.
Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.
This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.
The scanner identified 99 distinct pattern matches across 8 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.
Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | test/sandbox/winsrt.test.ts | 721 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 723 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 743 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 745 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 794 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 796 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 829 | // ── loopback port-range fence ──────────────────────────────────── | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 862 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 864 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 928 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 930 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1022 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1024 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1416 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1418 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | .github/workflows/integration-tests.yml | 56 | # ─── Windows: srt-win helper binary ───────────────────────────── | COMMENT |
| MEDIUM | src/cli.ts | 49 | // ── Windows install/uninstall ───────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 50 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 52 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 359 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 361 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 462 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 464 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 541 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 543 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 1173 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 1175 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM⚡ | src/sandbox/windows-sandbox-utils.ts | 1400 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM⚡ | src/sandbox/windows-sandbox-utils.ts | 1402 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/sandbox/mandatory-deny-paths.test.ts | 378 | async function runSandboxedWriteWithGitConfig( | CODE |
| LOW | test/sandbox/mandatory-deny-paths.test.ts | 482 | async function runSandboxedWriteWithDenyPaths( | CODE |
| LOW | test/sandbox/mandatory-deny-paths.test.ts | 1017 | async function runSandboxedCommandWithDenyPaths( | CODE |
| LOW | test/sandbox/integration.test.ts | 43 | function assertPrecompiledBpfInUse(): void { | CODE |
| LOW | src/sandbox/sandbox-utils.ts | 51 | export function normalizeCaseForComparison(pathStr: string): string { | CODE |
| LOW | src/sandbox/sandbox-utils.ts | 79 | function containsGlobCharsForPlatform(p: string): boolean { | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 240 | function findFirstNonExistentComponent(targetPath: string): string { | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 261 | async function linuxGetMandatoryDenyPaths( | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 399 | function registerExitCleanupHandler(): void { | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 591 | export async function initializeLinuxNetworkBridge( | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 755 | function resolveApplySeccompPrefix( | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1396 | export async function wrapCommandWithSandboxLinux( | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 60 | export function macGetMandatoryDenyPatterns(allowGitConfig = false): string[] { | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 144 | function generateMoveBlockingRules( | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 783 | export function wrapCommandWithSandboxMacOS( | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 952 | export function startMacOSSandboxLogMonitor( | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 290 | function shouldTerminateTLSForHost(host: string): boolean { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 774 | function getCredentialRestrictions( | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 837 | function getCredentialDenyReadPaths( | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 963 | function computeWindowsFsAccessSet(c: SandboxRuntimeConfig): { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1053 | function getNetworkRestrictionConfig(): NetworkRestrictionConfig { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1093 | function getEnableWeakerNestedSandbox(): boolean | undefined { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1097 | function getEnableWeakerNetworkIsolation(): boolean | undefined { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1109 | function getMandatoryDenySearchDepth(): number { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1145 | async function waitForNetworkInitialization(): Promise<boolean> { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1838 | function annotateStderrWithSandboxFailures( | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1868 | function getLinuxGlobPatternWarnings(): string[] { | CODE |
| LOW | src/sandbox/generate-seccomp-filter.ts | 160 | export function getApplySeccompBinaryPath( | CODE |
| LOW | src/sandbox/domain-pattern.ts | 52 | export function isInjectHostCoveredByAllowedDomains( | CODE |
| LOW | src/sandbox/linux-violation-monitor.ts | 71 | export function startLinuxSandboxViolationMonitor( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 689 | export function getWindowsSandboxUserStatus( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 1279 | export function wrapCommandWithSandboxWindows(p: WindowsSandboxParams): { | CODE |
| LOW⚡ | src/sandbox/windows-sandbox-utils.ts | 1407 | export function windowsInstallInstructions( | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/sandbox/glob-expand.test.ts | 41 | const RAW_BASE_DIR = join(tmpdir(), 'glob-expand-test-' + Date.now()) | COMMENT |
| LOW | test/sandbox/winsrt.test.ts | 521 | const sl = '6a1e0f80-2b3c-4d5e-9f8a-1b2c3d4e5f60' | COMMENT |
| LOW | test/sandbox/winsrt.test.ts | 1421 | // tls-terminate-proxy.test.ts); these rows prove the sandboxed | COMMENT |
| LOW | test/sandbox/winsrt.test.ts | 1681 | it.skipIf(NODE === undefined)( | COMMENT |
| LOW | test/sandbox/integration.test.ts | 521 | // The two network-allowlist tests below assert the proxy's 403 body | COMMENT |
| LOW | src/sandbox/sandbox-utils.ts | 481 | // one port, anything that actually speaks SOCKS to this URL still | COMMENT |
| LOW | src/sandbox/mitm-ca.ts | 321 | // Issuer Name: RFC 5280 §5.1.2.3 requires this match the CA subject | COMMENT |
| LOW | src/sandbox/mitm-leaf.ts | 61 | // don't enforce this, but requests/urllib3/httpx/google-auth all reject | COMMENT |
| LOW | src/sandbox/tls-terminate-proxy.ts | 201 | req: IncomingMessage, | COMMENT |
| LOW | src/sandbox/tls-terminate-proxy.ts | 221 | // with `Host: B` (where B is some other allowlisted host). If we | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 901 | const args: string[] = [] | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1061 | // Handle non-existent paths by mounting /dev/null to block creation. | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1241 | // realPath was already normalized (tilde-expanded, realpath'd) by the | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1261 | // --ro-bind /dev/null <host> from denyRead, which landed first. | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1321 | // maskedFiles holds both the symlink path and its resolved target so | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1621 | // Mount fresh /proc if PID namespace is isolated (secure mode). | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1641 | COMMENT | |
| LOW | src/sandbox/macos-sandbox-utils.ts | 321 | // Allow stat/lstat on all directories so that realpath() can traverse | COMMENT |
| LOW | src/sandbox/macos-sandbox-utils.ts | 661 | // ::ffff:127.0.0.1, which Seatbelt's "localhost" filter does not match. | COMMENT |
| LOW | src/sandbox/sandbox-manager.ts | 121 | // under a different SID. | COMMENT |
| LOW | src/sandbox/sandbox-manager.ts | 521 | `(thumb=${installed.thumb}) doesn't match this ` + | COMMENT |
| LOW | src/sandbox/sandbox-manager.ts | 1261 | } | COMMENT |
| LOW | src/sandbox/sandbox-manager.ts | 1421 | // expand, normalize, missing→drop) — so a per-exec entry | COMMENT |
| LOW | src/sandbox/sandbox-config.ts | 961 | entry: { mode: string; injectHosts?: string[] }, | COMMENT |
| LOW | src/sandbox/windows-sandbox-utils.ts | 1281 | env: NodeJS.ProcessEnv | COMMENT |
| LOW | src/sandbox/windows-sandbox-utils.ts | 1301 | p.proxyAuthToken, | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/sandbox/macos-seatbelt.test.ts | 393 | // Step 1: Try to rename the denied directory | COMMENT |
| LOW | test/sandbox/symlink-boundary.test.ts | 81 | // Step 1: Verify sandbox correctly blocks writes outside workspace | COMMENT |
| LOW | test/sandbox/symlink-boundary.test.ts | 107 | // Step 2: Create symlink /tmp/claude -> / | COMMENT |
| LOW | test/sandbox/symlink-boundary.test.ts | 131 | // Step 3: Verify sandbox still blocks writes outside workspace | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/sandbox/macos-seatbelt.test.ts | 393 | // Step 1: Try to rename the denied directory | COMMENT |
| LOW | test/sandbox/symlink-boundary.test.ts | 81 | // Step 1: Verify sandbox correctly blocks writes outside workspace | COMMENT |
| LOW | test/sandbox/symlink-boundary.test.ts | 107 | // Step 2: Create symlink /tmp/claude -> / | COMMENT |
| LOW | test/sandbox/symlink-boundary.test.ts | 131 | // Step 3: Verify sandbox still blocks writes outside workspace | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| HIGH | test/sandbox/macos-allow-local-binding.test.ts | 56 | print('IPC', cli.recv(2).decode()) | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | README.md | 9 | > The Sandbox Runtime is a research preview developed for [Claude Code](https://www.claude.com/product/claude-code) to e | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/sandbox/credential-mask-files.test.ts | 642 | b64u('{"sub":"1234567890","name":"John Doe","iat":1516239022}') + | CODE |