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 5,089 GitHub stars. SynthScan v2.0 examined 55,504 lines of code across 116 source files, recording 138 pattern matches distributed across 8 syntactic categories. The overall adjusted score of 3.9 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).
This chart maps the temporal evolution of the adjusted synthetic code score across successive scan runs. An upward trajectory indicates ongoing incorporation of AI-generated code or expanding LLM-assisted scaffolding; a stable or declining trajectory may reflect active human refactoring, code removal, or the adoption of stricter authorship policies. The dashed secondary line (right axis) independently tracks total raw pattern hit count, which can diverge from the normalised score when codebase size changes significantly between scans.
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 138 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 | 625 | // ════════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 627 | // ════════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1343 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1345 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1365 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1367 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1416 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1418 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1451 | // ── loopback port-range fence ──────────────────────────────────── | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1484 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1486 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1550 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1552 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1644 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 1646 | // ════════════════════════════════════════════════════════════════ | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 2040 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 2042 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 2468 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | test/sandbox/winsrt.test.ts | 2475 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | .github/workflows/integration-tests.yml | 66 | # ─── Windows: srt-win helper binary ───────────────────────────── | COMMENT |
| MEDIUM | src/cli.ts | 49 | // ── Windows install/uninstall ───────────────────────────────── | COMMENT |
| MEDIUM⚡ | src/sandbox/windows-sandbox-utils.ts | 2147 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM⚡ | src/sandbox/windows-sandbox-utils.ts | 2149 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 58 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 60 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 153 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 155 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 479 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 481 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 606 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 608 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 781 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 783 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 1998 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | src/sandbox/windows-sandbox-utils.ts | 2000 | // ──────────────────────────────────────────────────────────────────── | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/sandbox/http-proxy-verdict-liveness.test.ts | 273 | async function clientSupportsHalfOpenReceive(): Promise<boolean> { | CODE |
| 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/sandbox-utils.ts | 824 | export function encodedCommandFromProxyUser( | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 254 | function findFirstNonExistentComponent(targetPath: string): string { | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 275 | async function linuxGetMandatoryDenyPaths( | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 413 | function registerExitCleanupHandler(): void { | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 605 | export async function initializeLinuxNetworkBridge( | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 769 | function resolveApplySeccompPrefix( | CODE |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1686 | export async function wrapCommandWithSandboxLinux( | CODE |
| LOW | src/sandbox/body-substitution.ts | 107 | export function createBodySubstitutionTransform( | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 79 | export function macGetMandatoryDenyPatterns(allowGitConfig = false): string[] { | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 331 | function generateReadDenyUnlinkRules( | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 448 | function generateMoveBlockingRules( | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 995 | export function wrapCommandWithSandboxMacOS( | CODE |
| LOW | src/sandbox/macos-sandbox-utils.ts | 1204 | export function startMacOSSandboxLogMonitor( | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 407 | function buildBodyCredentialInjector(): GetBodySubstitutions | undefined { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 476 | function shouldTerminateTLSForHost(host: string): boolean { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1066 | function getCredentialRestrictions( | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1147 | function getCredentialDenyReadPaths( | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1273 | function computeWindowsFsAccessSet(c: SandboxRuntimeConfig): { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1370 | function getNetworkRestrictionConfig(): NetworkRestrictionConfig { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1410 | function getEnableWeakerNestedSandbox(): boolean | undefined { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1414 | function getEnableWeakerNetworkIsolation(): boolean | undefined { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1426 | function getMandatoryDenySearchDepth(): number { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 1477 | async function waitForNetworkInitialization(): Promise<boolean> { | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 2222 | function annotateStderrWithSandboxFailures( | CODE |
| LOW | src/sandbox/sandbox-manager.ts | 2252 | function getLinuxGlobPatternWarnings(): string[] { | CODE |
| LOW | src/sandbox/generate-seccomp-filter.ts | 160 | export function getApplySeccompBinaryPath( | CODE |
| LOW | src/sandbox/domain-pattern.ts | 108 | export function matchesDomainPatternWithPort( | CODE |
| LOW | src/sandbox/domain-pattern.ts | 134 | export function isInjectHostCoveredByAllowedDomains( | CODE |
| LOW | src/sandbox/linux-violation-monitor.ts | 76 | export function startLinuxSandboxViolationMonitor( | CODE |
| LOW⚡ | src/sandbox/windows-sandbox-utils.ts | 2154 | export function windowsInstallInstructions( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 861 | export function checkWindowsSandboxStatus( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 873 | export async function checkWindowsSandboxStatusAsync( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 1040 | export function getWindowsSandboxUserStatus( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 1049 | export async function getWindowsSandboxUserStatusAsync( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 1241 | export async function ensurePersistentWindowsCa( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 1601 | export async function installWindowsSandboxAsync( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 2020 | export function wrapCommandWithSandboxWindows(p: WindowsSandboxParams): { | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 2186 | function interpretDependencyProbes( | CODE |
| LOW | src/sandbox/windows-sandbox-utils.ts | 2279 | export async function checkWindowsDependenciesAsync( | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/sandbox/credential-mask-sigv4.test.ts | 301 | ) | COMMENT |
| LOW | test/sandbox/glob-expand.test.ts | 41 | COMMENT | |
| LOW | test/sandbox/winsrt.test.ts | 621 | }, | COMMENT |
| LOW | test/sandbox/winsrt.test.ts | 2041 | // Group G — tlsTerminate CA trust via env vars | COMMENT |
| LOW | test/sandbox/winsrt.test.ts | 2241 | // Mirror the network + H-rows describes: leave no WFP filters, | COMMENT |
| LOW | test/sandbox/winsrt.test.ts | 2401 | async () => { | COMMENT |
| LOW | test/sandbox/winsrt.test.ts | 2461 | expectStatus('G9', r, [0]) | 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 | 321 | pathPattern = stripExtendedPathPrefix(expandWindowsEnvRefs(pathPattern)) | COMMENT |
| LOW | src/sandbox/sandbox-utils.ts | 541 | } | COMMENT |
| LOW | src/sandbox/sandbox-utils.ts | 561 | // gRPC-based tools. gRPC C-core (every google-cloud-* Python client, and | COMMENT |
| LOW | src/sandbox/sandbox-utils.ts | 601 | } | COMMENT |
| LOW | src/sandbox/http-proxy.ts | 261 | COMMENT | |
| LOW | src/sandbox/http-proxy.ts | 281 | // (checked again at write time via readableEnded). EOF | COMMENT |
| LOW | src/sandbox/http-proxy.ts | 301 | // | COMMENT |
| LOW | src/sandbox/http-proxy.ts | 441 | if (clientGone || socket.destroyed) { | COMMENT |
| LOW | src/sandbox/http-proxy.ts | 461 | // > external MITM unix socket | COMMENT |
| LOW | src/sandbox/http-proxy.ts | 681 | }) | COMMENT |
| LOW | src/sandbox/request-filter.ts | 101 | ): Promise<Readable | null> { | 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 | 341 | // Host-header note below). | COMMENT |
| LOW | src/sandbox/tls-terminate-proxy.ts | 401 | // substitution below replaces) but on the POST-strip view: the plan's | COMMENT |
| LOW | src/sandbox/tls-terminate-proxy.ts | 521 | // TODO(terminating-tls): honour parentProxy for the upstream leg. | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 921 | // denyWrite binds are buffered and emitted after denyRead processing so that | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 941 | COMMENT | |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1001 | continue | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1021 | // window — the fail-closed direction, since a link now pointing into a | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1141 | const seenDenyWrite = new Set<string>() | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1181 | // Keep every spelling this dest is reached through (the emission | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1201 | // through). Rationale: the only writable emissions that land after the | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1261 | if (rawPath.startsWith('/dev/')) { | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1441 | // Non-glob spellings arrive slash-free from normalizePathForSandbox — the | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1541 | maskedFiles.set(dest, fakePath) | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1941 | // If we don't have --unshare-pid, it is possible to escape the sandbox. | COMMENT |
| LOW | src/sandbox/linux-sandbox-utils.ts | 1961 | // | COMMENT |
| LOW | src/sandbox/macos-sandbox-utils.ts | 561 | resolved.denies.map(d => d.path), | COMMENT |
| LOW | src/sandbox/macos-sandbox-utils.ts | 841 | ' )', | COMMENT |
| LOW | src/sandbox/macos-sandbox-utils.ts | 861 | // | COMMENT |
| LOW | src/sandbox/macos-sandbox-utils.ts | 1101 | // env vars above, so the agent translates them into system properties | COMMENT |
| LOW | src/sandbox/sandbox-manager.ts | 141 | // Windows: the resolved access set that was actually applied at | COMMENT |
| LOW | src/sandbox/sandbox-manager.ts | 161 | // Resolved once at initialize() (`resolveSrtWin` stats the disk). | COMMENT |
| LOW | src/sandbox/sandbox-manager.ts | 781 | } | COMMENT |
| LOW | src/sandbox/sandbox-manager.ts | 1801 | // The dedup against `windowsFsStampedSet` is an OPTIMIZATION, | COMMENT |
| LOW | src/sandbox/sandbox-config.ts | 1181 | ) => { | COMMENT |
| LOW | src/sandbox/windows-sandbox-utils.ts | 2021 | argv: string[] | COMMENT |
| LOW | src/sandbox/windows-sandbox-utils.ts | 2041 | p.caCertPath?.replace(/\\/g, '/'), | 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 |