Deterministic testing tools for MCP servers
This report summarizes scanner evidence for modelcontextprotocol/inspector, a TypeScript project with 11,200 GitHub stars. SynthScan examined 432,406 lines of code across 1525 source files, recording 695 pattern matches distributed across 10 syntactic categories. The legacy adjusted pattern signal is 1.7 (Low pattern signal); it is not an authorship estimate.
Use the findings to ask whether maintainers can explain intent, verify dependencies, simplify unnecessary scaffolding, and focus review effort. Risk Payload v1 adds ownership, supply-chain, over-engineering, and review-effort vectors when available. These are prompts for human verification, not probabilities, security findings, or measured maintenance costs.
Use each vector to guide manual verification of the underlying findings.
Payload schema: 1.0.0 · Engine: 2.0.0 · Scoring: heuristic-density-v1 · Scan date: 2026-10-31.
Can maintainers explain intent, assumptions, and trade-offs? 676 finding(s).
Are imports declared and package/API names verified? 18 finding(s).
Are wrappers, guards, and repeated structures necessary? 288 finding(s).
Which changes need focused human review? 695 finding(s).
This chart tracks the legacy adjusted pattern score across scan runs. Changes can reflect source changes, scan coverage, or detector/scoring versions; they do not measure AI adoption or prove that a team refactored code. Compare runs only when their scoring versions are compatible. The dashed line tracks the raw pattern-hit count.
Groups findings by configured severity weight. Severity is not a confidence estimate, security rating, or proof that a package is missing. Verify imports against the project's manifests and inspect each finding in its local design context.
This horizontal bar chart shows where configured pattern scores accumulate across directories. Treat the bars as locations to inspect, not as evidence of authorship or code quality. Use the file-level findings to decide whether a directory needs a focused ownership, dependency, complexity, or review check.
The scanner identified 695 distinct pattern matches across 10 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a detector match to inspect in context. 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 configured finding weight (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — legacy comment-context matches receive a ×1.5 score weight. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier under the legacy scoring model.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | tsconfig.lint.json | 1 | { | COMMENT |
| LOW | eslint.config.js | 1 | import js from "@eslint/js"; | COMMENT |
| LOW | eslint.config.js | 21 | // re-sync #1955 fixed sat here unreported while the identical shape was an | COMMENT |
| LOW | clients/launcher/tsconfig.test.json | 1 | { | COMMENT |
| LOW | clients/tui/tsdown.config.ts | 1 | import { defineConfig } from "tsdown"; | COMMENT |
| LOW | clients/tui/tsdown.config.ts | 21 | // mounts. That is the reported crash, and inlining them is its fix. | COMMENT |
| LOW | clients/tui/tsdown.config.ts | 41 | // `react` is deliberately external — the single instance every inlined | COMMENT |
| LOW | clients/tui/tsdown.config.ts | 61 | "@modelcontextprotocol/core", | COMMENT |
| LOW | clients/tui/tsdown.config.ts | 81 | // reached by a manifest edit rather than an omission. | COMMENT |
| LOW | clients/tui/vitest.config.ts | 21 | // here waits on a React commit under v8 instrumentation — the shape behind | COMMENT |
| LOW | clients/tui/__tests__/setup.ts | 1 | // Shared vitest setup for the TUI renderer tests. | COMMENT |
| LOW | clients/tui/__tests__/SkillsTab.test.tsx | 761 | // | COMMENT |
| LOW | clients/tui/__tests__/helpers/renderTui.tsx | 1 | // A drop-in replacement for ink-testing-library's `render` that strips ANSI | COMMENT |
| LOW | clients/tui/src/utils/clipboard.ts | 1 | // Getting a value out of the TUI and onto the user's clipboard (#2421). | COMMENT |
| LOW | clients/tui/src/utils/schemaToForm.ts | 421 | type: "select", | COMMENT |
| LOW | clients/web/tsdown.runner.config.ts | 41 | // actually reaches it is a function of what `core/` imports, not of this | COMMENT |
| LOW | clients/web/vite.config.ts | 41 | // misclassification trap where a file's environment depended on whether | COMMENT |
| LOW | clients/web/vite.config.ts | 61 | // | COMMENT |
| LOW | clients/web/vite.config.ts | 101 | export default defineConfig(({ command }) => { | COMMENT |
| LOW | clients/web/vite.config.ts | 121 | // (`core/mcp/remote/node/server.ts`), so Vite's config bundler (Rolldown) | COMMENT |
| LOW | clients/web/vite.config.ts | 141 | // Browser code reaches the node-side stack via the Hono plugin only. | COMMENT |
| LOW | clients/web/vite.config.ts | 161 | find, | COMMENT |
| LOW | clients/web/vite.config.ts | 181 | // picking a different port (which would leave `allowedOrigins` wrong). | COMMENT |
| LOW | clients/web/vite.config.ts | 241 | "src/components/**/types.ts", | COMMENT |
| LOW | clients/web/vite.config.ts | 301 | // reach core/, which leaves core/'s own bare imports with nothing to | COMMENT |
| LOW | clients/web/vite.config.ts | 321 | // `AsyncTaskManager destroyed` output. The component tests only assert | COMMENT |
| LOW | clients/web/vite.config.ts | 341 | // Integration tests run in the integration project below (node env). | COMMENT |
| LOW | clients/web/vite.config.ts | 381 | // Same keychain guard as the unit project: never let a test that | COMMENT |
| LOW | clients/web/vite.config.ts | 421 | storybookTest({ | COMMENT |
| LOW | clients/web/vite.config.ts | 461 | }, | COMMENT |
| LOW | clients/web/server/web-server-config.ts | 541 | // host, an explicit `:80` — match the canonical `Origin` the browser sends | COMMENT |
| LOW | clients/web/server/vite-base-config.ts | 21 | "atomically", | COMMENT |
| LOW | clients/web/server/vite-base-config.ts | 41 | // it is CJS with a `graceful-fs`/`signal-exit`/`retry` graph that Vite's | COMMENT |
| LOW | clients/web/server/browser-externalized-builtin-gate.ts | 21 | COMMENT | |
| LOW | clients/web/server/vite-hono-plugin.ts | 41 | // when none is supplied). Captured here so the `transformIndexHtml` hook — | COMMENT |
| LOW | clients/web/server/start-vite-dev-server.ts | 61 | host: config.hostname, | COMMENT |
| LOW | clients/web/server/run-web.ts | 121 | protocolEra?: ServerProtocolEra; | COMMENT |
| LOW | clients/web/static/sandbox_proxy.html | 121 | COMMENT | |
| LOW | clients/web/static/sandbox_proxy.html | 161 | // origins. | COMMENT |
| LOW | clients/web/static/sandbox_proxy.html | 181 | // | COMMENT |
| LOW | clients/web/static/sandbox_proxy.html | 221 | } | COMMENT |
| LOW | clients/web/static/sandbox_proxy.html | 281 | } | COMMENT |
| LOW | clients/web/static/sandbox_proxy.html | 301 | innerOrigin = srcUrl.origin; | COMMENT |
| LOW | clients/web/src/App.tsx | 341 | // to read *currently* rather than as of the render that created it. Declared | COMMENT |
| LOW | clients/web/src/App.tsx | 361 | // the level — visible on the auth-recovery path, which reconnects the same | COMMENT |
| LOW | clients/web/src/App.tsx | 421 | activeServerEntry?.settings?.paginatedLists ?? false; | COMMENT |
| LOW | clients/web/src/App.tsx | 761 | // OAuth details — both are co-located here so the modal opens against the | COMMENT |
| LOW | clients/web/src/App.tsx | 781 | // | COMMENT |
| LOW | clients/web/src/App.tsx | 861 | // applies to the instance that exists now. | COMMENT |
| LOW | clients/web/src/App.tsx | 1121 | COMMENT | |
| LOW | clients/web/src/App.tsx | 1241 | // ServerConfigModal's own `useValueChange` reset then blanks the open form | COMMENT |
| LOW | clients/web/src/App.tsx | 1281 | // | COMMENT |
| LOW | clients/web/src/App.tsx | 1361 | if (baseline) syncHeadersReconnectToast(id, baseline); | COMMENT |
| LOW | clients/web/src/App.tsx | 1741 | () => setConnectionInfoModalOpen(true), | COMMENT |
| LOW | clients/web/src/App.tsx | 1761 | // transport close propagate. `onDisconnect` is that `try/finally` alone. | COMMENT |
| LOW | clients/web/src/App.test.tsx | 41 | vi.mock("@mantine/notifications", () => ({ | COMMENT |
| LOW | clients/web/src/App.test.tsx | 61 | // failure). | COMMENT |
| LOW | clients/web/src/App.test.tsx | 3181 | }; | COMMENT |
| LOW | …eb/src/types/react-syntax-highlighter-prism-light.d.ts | 1 | // Type stub for the deep `react-syntax-highlighter` runtime import. Under | COMMENT |
| LOW | clients/web/src/test/setup.ts | 1 | import "@testing-library/jest-dom/vitest"; | COMMENT |
| 316 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | clients/tui/__tests__/tsdownConfig.test.ts | 100 | function reactRenderingDependencies(): string[] { | CODE |
| LOW | clients/tui/src/utils/oauthDisplay.ts | 25 | export function formatClientRegistrationKind( | CODE |
| LOW | clients/web/vite.config.ts | 73 | function browserExternalizedBuiltinGate(): Plugin { | CODE |
| LOW | clients/web/server/web-server-config.ts | 116 | function defaultEnvironmentFromProcess( | CODE |
| LOW | clients/web/server/web-server-config.ts | 155 | export function webServerConfigToInitialPayload( | CODE |
| LOW | clients/web/server/web-server-config.ts | 621 | export function buildWebServerConfigFromEnv(): WebServerConfig { | CODE |
| LOW | clients/web/server/app-origin-controller.ts | 242 | export function createAppOriginController( | CODE |
| LOW | clients/web/server/browser-externalized-builtin-gate.ts | 39 | export function isBrowserExternalizedBuiltinLog( | CODE |
| LOW | clients/web/server/browser-externalized-builtin-gate.ts | 50 | export function browserExternalizedBuiltinError(messages: string[]): Error { | CODE |
| LOW | clients/web/server/browser-externalized-builtin-gate.ts | 87 | export function createBrowserExternalizedBuiltinGate(): BrowserExternalizedBuiltinGate { | CODE |
| LOW | clients/web/server/public-address.ts | 182 | export function resolveAppOriginPublicOrigin( | CODE |
| LOW | clients/web/src/App.test.tsx | 2056 | async function openSettingsForConnectedServer( | CODE |
| LOW | clients/web/src/test/scrollAreaStoryAssertions.ts | 9 | export async function expectScrollbarGutterIdleHidden( | CODE |
| LOW | clients/web/src/test/scrollAreaStoryAssertions.ts | 50 | export async function expectNoHorizontalOverflow(canvasElement: HTMLElement) { | CODE |
| LOW | clients/web/src/test/renderWithMantine.tsx | 76 | export function renderWithMantineTransitions( | CODE |
| LOW | clients/web/src/test/renderWithMantine.tsx | 315 | function assertLiveContainersConnected( | CODE |
| LOW | clients/web/src/test/core/auth/ema/wire.test.ts | 49 | async function useRealDiscoverAndRequestJwtAuthGrant() { | CODE |
| LOW | …t/core/mcp/inspectorClient-peer-handler-timing.test.ts | 1317 | function clientWithFreshTransports() { | CODE |
| LOW | …test/core/mcp/state/resourceSubscriptionsState.test.ts | 12 | function waitForSubscriptionsChange( | CODE |
| LOW | …/src/test/integration/auth/node/secretStoreContract.ts | 33 | export function describeSecretStoreContract( | CODE |
| LOW | …c/test/integration/auth/node/file-secret-store.test.ts | 878 | async function writeEncryptedFixtureWithPayload( | CODE |
| LOW | …c/test/integration/auth/node/file-secret-store.test.ts | 893 | async function writeEncryptedFixtureWithPlaintext( | CODE |
| LOW | …/integration/auth/node/oauth-secrets-namespace.test.ts | 162 | async function assertTwoProfileIsolation(store: SecretStore): Promise<void> { | CODE |
| LOW | …ients/web/src/test/integration/mcp/ema-mock-servers.ts | 300 | export async function startMockResourceAsServer( | CODE |
| LOW | …c/test/integration/mcp/inspectorClient-ema-e2e.test.ts | 56 | async function waitForProtectedResourceMetadata( | CODE |
| LOW | …ration/mcp/inspectorClient-timeout-diagnostics.test.ts | 198 | async function waitForNotificationStream(c: InspectorClient): Promise<void> { | CODE |
| LOW | …tegration/mcp/inspectorClient-modern-era-oauth.test.ts | 84 | async function startProtectedModernServer(): Promise<string> { | CODE |
| LOW | …t/integration/mcp/remote/server-extra-coverage.test.ts | 1114 | async function readSuppressNotificationStream() { | CODE |
| LOW | …st/integration/mcp/remote/remote-auth-branches.test.ts | 65 | async function startUnauthorizedUpstream(): Promise<{ | CODE |
| LOW | …egration/mcp/remote/remoteClientTransport-unit.test.ts | 120 | function createPushableEventStream() { | CODE |
| LOW | …/src/test/integration/helpers/oauth-client-fixtures.ts | 15 | export function createStaticRedirectUrlProvider( | CODE |
| LOW | …/src/test/integration/helpers/oauth-client-fixtures.ts | 103 | export async function createClientMetadataServer( | CODE |
| LOW | …/src/test/integration/helpers/oauth-client-fixtures.ts | 153 | export async function completeOAuthAuthorization( | CODE |
| LOW | clients/web/src/utils/sandbox-csp.ts | 144 | export function approveSandboxPermissions( | CODE |
| LOW | clients/web/src/utils/jsonObjectDraft.ts | 49 | export function findUnsendableNumberLiteral(text: string): string | null { | CODE |
| LOW | clients/web/src/utils/correlateTransportErrors.ts | 52 | function indexTransportFetchErrors( | CODE |
| LOW | clients/web/src/utils/correlateTransportErrors.ts | 133 | export function correlatedFetchStatusById( | CODE |
| LOW | clients/web/src/utils/mcpNetworkHeaders.ts | 266 | export function classifyProtocolSpecError( | CODE |
| LOW | clients/web/src/utils/malformedListReport.ts | 40 | export function visibleMalformedListItems( | CODE |
| LOW | clients/web/src/utils/connectionActivity.ts | 27 | export function formatOutstandingRequests( | CODE |
| LOW | clients/web/src/utils/replayableProtocolMethods.ts | 26 | export function isReplayableProtocolMethod(method: string): boolean { | CODE |
| LOW | clients/web/src/utils/oauthClearKey.ts | 68 | export function resolveOAuthClearIdentity({ | CODE |
| LOW | clients/web/src/utils/toasts/progressToasts.ts | 33 | export function formatProgressToastMessage( | CODE |
| LOW | …xperimentalFeaturesPanel/ExperimentalFeaturesPanel.tsx | 189 | export function ExperimentalFeaturesPanel({ | CODE |
| LOW⚡ | …nents/groups/ServerSettingsForm/ServerSettingsForm.tsx | 662 | function changeAuthorizationParams( | CODE |
| LOW⚡ | …nents/groups/ServerSettingsForm/ServerSettingsForm.tsx | 668 | function handleRequestRefreshTokenChange( | CODE |
| LOW⚡ | …nents/groups/ServerSettingsForm/ServerSettingsForm.tsx | 677 | function handleScopeOnRefreshChange( | CODE |
| LOW⚡ | …nents/groups/ServerSettingsForm/ServerSettingsForm.tsx | 686 | function handleRevokeOnClearChange( | CODE |
| LOW⚡ | …nents/groups/ServerSettingsForm/ServerSettingsForm.tsx | 695 | function handleAddAuthorizationParam(): void { | CODE |
| LOW⚡ | …nents/groups/ServerSettingsForm/ServerSettingsForm.tsx | 699 | function handleRemoveAuthorizationParam(index: number): void { | CODE |
| LOW⚡ | …nents/groups/ServerSettingsForm/ServerSettingsForm.tsx | 705 | function handleAuthorizationParamChange( | CODE |
| LOW | …ents/groups/ResourceControls/ResourceControls.test.tsx | 56 | function ControlledResourceControls(props: Partial<ResourceControlsProps>) { | CODE |
| LOW | …endingClientRequestModal/PendingClientRequestModal.tsx | 87 | function createDefaultSamplingResult(): CreateMessageResult { | CODE |
| LOW | …endingClientRequestModal/PendingClientRequestModal.tsx | 246 | export function PendingClientRequestModal({ | CODE |
| LOW | …nents/groups/ClientSettingsForm/ClientSettingsForm.tsx | 94 | function registrationRejectionSummary(error: OAuthRegistrationError): string { | CODE |
| LOW | …ents/groups/ClientSettingsForm/clientSettingsValues.ts | 172 | export function canPersistClientSettingsDraft( | CODE |
| LOW | …/groups/ClientSettingsForm/ClientSettingsForm.test.tsx | 28 | function ClientSettingsFormHarness({ | CODE |
| LOW⚡ | …nts/groups/ServerSettingsModal/ServerSettingsModal.tsx | 219 | function handlePaginatedListsChange(value: boolean) { | CODE |
| LOW⚡ | …nts/groups/ServerSettingsModal/ServerSettingsModal.tsx | 223 | function handleSuppressNotificationStreamChange(value: boolean) { | CODE |
| LOW⚡ | …nts/groups/ServerSettingsModal/ServerSettingsModal.tsx | 231 | function handleAdvertisedExtensionChange(key: string, checked: boolean) { | CODE |
| 227 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| HIGH | …web/src/test/integration/mcp/import/serverJson.test.ts | 28 | name: "YOUR_API_KEY", | CODE |
| HIGH | …web/src/test/integration/mcp/import/serverJson.test.ts | 73 | name: "YOUR_API_KEY", | CODE |
| HIGH | …web/src/test/integration/mcp/import/serverJson.test.ts | 340 | YOUR_API_KEY: "secret", | CODE |
| HIGH | …web/src/test/integration/mcp/import/serverJson.test.ts | 346 | env: { YOUR_API_KEY: "secret", LOG_LEVEL: "debug" }, | CODE |
| HIGH | …web/src/test/integration/mcp/import/serverJson.test.ts | 425 | YOUR_API_KEY: "secret", | CODE |
| HIGH | …web/src/test/integration/mcp/import/serverJson.test.ts | 430 | env: { YOUR_API_KEY: "secret", LOG_LEVEL: "info" }, | CODE |
| HIGH | clients/cli/README.md | 82 | npx @modelcontextprotocol/inspector --cli https://my-mcp-server.example.com --transport http --method tools/list --heade | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | …groups/ServerImportJsonModal/ServerImportJsonModal.tsx | 19 | * Display shell for the registry `server.json` import (#1348). All orchestration | COMMENT |
| MEDIUM⚡ | docs/quality-gate.md | 40 | | `npm run coverage` | The **per-file ≥90% gate** (lines/statements/functions/branches) under v8 instru | CODE |
| MEDIUM⚡ | docs/quality-gate.md | 49 | | `npm run test:scripts` | Table-driven unit tests (`node --test`) for the guard's own pure parsers (`scrip | CODE |
| MEDIUM⚡ | docs/quality-gate.md | 55 | | `npm run local:gate` | **Mandatory pre-push command.** `local:validate` → `local:dco` → `verify:skills: | CODE |
| MEDIUM | docs/inspector-roadmap-2026-h2.md | 23 | - [3.1 Agentic messaging primitives](#31-agentic-messaging-primitives) | CODE |
| MEDIUM | specification/v2_auth_mid_session.md | 285 | ### App orchestration (`clients/web/src/App.tsx`) | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | clients/web/src/test/narrowSidebarDecorator.tsx | 15 | * (#2675). A raw `div` with inline style is deliberate: this is test harness, | COMMENT |
| MEDIUM | clients/web/src/utils/maskSecrets.ts | 65 | // serializations — reformatting alone can't trip the flag, and it's robust if | COMMENT |
| MEDIUM | …ts/web/src/components/groups/ViewHeader/ViewHeader.tsx | 74 | // signal, gating on that would be more robust than a fixed timer. | COMMENT |
| MEDIUM | clients/web/src/lib/authToken.ts | 22 | // is the robust path: it survives a bare-URL reload, a bookmark, or a | COMMENT |
| MEDIUM | clients/cli/__tests__/emit-result.test.ts | 204 | // stays per-tool robust. readResource must never be reached here. | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | …nts/web/src/test/core/auth/authorizationParams.test.ts | 62 | login_hint: "user@example.com", | CODE |
| LOW | …nts/web/src/test/core/auth/authorizationParams.test.ts | 68 | expect(merged.searchParams.get("login_hint")).toBe("user@example.com"); | CODE |
| LOW | …rc/components/groups/SchemaForm/SchemaForm.stories.tsx | 116 | name: { type: "string", title: "Name", default: "John Doe" }, | CODE |
| LOW | …b/src/components/groups/SchemaForm/SchemaForm.test.tsx | 2150 | '{"kind":"sms","phone":"555-0100"}', | CODE |
| LOW | …/components/elements/CopyButton/CopyButton.stories.tsx | 21 | "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore mag | CODE |
| LOW | …/components/elements/CopyButton/CopyButton.stories.tsx | 21 | "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore mag | CODE |
| LOW | …nents/elements/MessageBubble/MessageBubble.stories.tsx | 59 | text: "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et do | CODE |
| LOW | …nents/elements/MessageBubble/MessageBubble.stories.tsx | 59 | text: "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et do | CODE |
| LOW | …/components/views/InspectorView/InspectorView.test.tsx | 1140 | appArgs: { kind: "sms", phone: "555-0100" }, | CODE |
| LOW | …/components/views/InspectorView/InspectorView.test.tsx | 1159 | expect(await screen.findByDisplayValue("555-0100")).toBeInTheDocument(); | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| HIGH | clients/cli/src/completion.ts | 201 | elif [ "$prev" = "=" ] && [ "$COMP_CWORD" -ge 3 ]; then | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | clients/web/src/App.css | 341 | /* ── Header connect/disconnect animations (#1450) ────────── */ | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | …/integration/auth/node/oauth-secrets-namespace.test.ts | 1118 | // Step 4: a keychain run on the stamped file. Its read already sees | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | …/integration/auth/node/oauth-secrets-namespace.test.ts | 1118 | // Step 4: a keychain run on the stamped file. Its read already sees | COMMENT |