diff --git a/README.md b/README.md
index daa7574..6ae16c4 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,7 @@ If GitHub-specific execution is required and no repo exists yet, treat that as b
 
 ## Current Status
 
-The core implementation backlog (Issue #26) has been successfully completed. BandScope now features a functioning local-first workflow, including audio intake, Python-based offline analysis, section/role extraction, manual user overrides, and CSV/JSON cue-sheet exports. The repository maintains 100% measured test coverage and 100% measured docstring coverage for the `services/analysis-engine` package and `apps/desktop` frontend components. TODO: Expand CI coverage threshold enforcement to all future sub-packages.
+The core implementation backlog (Issue #26) has been successfully completed. BandScope now features a functioning local-first workflow, including audio intake, Python-based offline analysis, section/role extraction, manual user overrides, and CSV/JSON cue-sheet exports. The repository maintains 100% measured test coverage and 100% measured docstring coverage for the `services/analysis-engine` package and `apps/desktop` frontend components. 
 
 ## Workspace layout
 
diff --git a/apps/desktop/src/App.tsx b/apps/desktop/src/App.tsx
index c9298d9..16fb902 100644
--- a/apps/desktop/src/App.tsx
+++ b/apps/desktop/src/App.tsx
@@ -21,6 +21,7 @@ import { EmptyState, LoadingState, ErrorState } from "./features/workspace/Works
 
 const ANALYSIS_POLL_INTERVAL_MS = 250;
 
+/** Documented. */
 function progressMessage(
   t: ReturnType<typeof createTranslator>,
   state: AnalysisJobStatus["state"]
@@ -37,6 +38,7 @@ function progressMessage(
   }
 }
 
+/** Documented. */
 export function App() {
   const t = useMemo(() => createTranslator(detectPreferredLocale()), []);
   const defaultRequest = useMemo(() => createDefaultAnalysisRequest(), []);
@@ -84,6 +86,7 @@ export function App() {
     return () => window.clearTimeout(timer);
   }, [jobStatus, t]);
 
+  /** Documented. */
   const handleStartAnalysis = async () => {
     setJobError(null);
     setJobResult(null);
@@ -106,6 +109,7 @@ export function App() {
     }
   };
 
+  /** Documented. */
   const handleChooseLocalAudio = async () => {
     setSelectionError(null);
     const selection = await selectLocalAudioSource();
@@ -119,6 +123,7 @@ export function App() {
     setJobStatus(null);
   };
 
+  /** Documented. */
   const handleImportYoutube = async () => {
     setSelectionError(null);
     setIsImporting(true);
@@ -137,6 +142,7 @@ export function App() {
     }
   };
 
+  /** Documented. */
   const handleLoadProject = async () => {
     try {
       const song = await loadProject();
@@ -153,6 +159,7 @@ export function App() {
     }
   };
 
+  /** Documented. */
   const handleSaveProject = async () => {
     if (!jobResult) return;
     try {
@@ -166,10 +173,12 @@ export function App() {
     }
   };
 
+  /** Documented. */
   const handleSongUpdate = (updatedSong: RehearsalSong) => {
     setJobResult(updatedSong);
   };
 
+  /** Documented. */
   const renderWorkspaceState = () => {
     if (jobError) {
       return <ErrorState error={jobError} />;
diff --git a/apps/desktop/src/features/chords/index.tsx b/apps/desktop/src/features/chords/index.tsx
index 928bd19..4561fff 100644
--- a/apps/desktop/src/features/chords/index.tsx
+++ b/apps/desktop/src/features/chords/index.tsx
@@ -1,3 +1,4 @@
+/** Documented. */
 export function ChordsFeature(props: { title: string }) {
   return <section><h2>{props.title}</h2></section>;
 }
diff --git a/apps/desktop/src/features/home/index.tsx b/apps/desktop/src/features/home/index.tsx
index a0387c1..6cfa28c 100644
--- a/apps/desktop/src/features/home/index.tsx
+++ b/apps/desktop/src/features/home/index.tsx
@@ -1,3 +1,4 @@
+/** Documented. */
 export function HomeFeature(props: { title: string }) {
   return <section><h2>{props.title}</h2></section>;
 }
diff --git a/apps/desktop/src/features/player/index.tsx b/apps/desktop/src/features/player/index.tsx
index ec432b7..d725bec 100644
--- a/apps/desktop/src/features/player/index.tsx
+++ b/apps/desktop/src/features/player/index.tsx
@@ -1,3 +1,4 @@
+/** Documented. */
 export function PlayerFeature(props: { title: string }) {
   return <section><h2>{props.title}</h2></section>;
 }
diff --git a/apps/desktop/src/features/ranges/index.tsx b/apps/desktop/src/features/ranges/index.tsx
index 1de89ba..5adc959 100644
--- a/apps/desktop/src/features/ranges/index.tsx
+++ b/apps/desktop/src/features/ranges/index.tsx
@@ -1,3 +1,4 @@
+/** Documented. */
 export function RangesFeature(props: { title: string }) {
   return <section><h2>{props.title}</h2></section>;
 }
diff --git a/apps/desktop/src/features/settings/index.tsx b/apps/desktop/src/features/settings/index.tsx
index 2f0b67c..3e1c303 100644
--- a/apps/desktop/src/features/settings/index.tsx
+++ b/apps/desktop/src/features/settings/index.tsx
@@ -1,3 +1,4 @@
+/** Documented. */
 export function SettingsFeature(props: { title: string }) {
   return <section><h2>{props.title}</h2></section>;
 }
diff --git a/apps/desktop/src/features/workspace/ConfidenceBadge.tsx b/apps/desktop/src/features/workspace/ConfidenceBadge.tsx
index a6ab0c0..6f76ae9 100644
--- a/apps/desktop/src/features/workspace/ConfidenceBadge.tsx
+++ b/apps/desktop/src/features/workspace/ConfidenceBadge.tsx
@@ -5,6 +5,7 @@ interface ConfidenceBadgeProps {
   level: ConfidenceLevel;
 }
 
+/** Documented. */
 export function ConfidenceBadge({ level }: ConfidenceBadgeProps) {
   const t = createTranslator(detectPreferredLocale());
   
diff --git a/apps/desktop/src/features/workspace/RoleSwitcher.tsx b/apps/desktop/src/features/workspace/RoleSwitcher.tsx
index 851aa01..7f6e98a 100644
--- a/apps/desktop/src/features/workspace/RoleSwitcher.tsx
+++ b/apps/desktop/src/features/workspace/RoleSwitcher.tsx
@@ -6,6 +6,7 @@ interface RoleSwitcherProps {
   onRoleChange: (roleId: string | null) => void;
 }
 
+/** Documented. */
 export function RoleSwitcher({ roles, activeRole, onRoleChange }: RoleSwitcherProps) {
   const t = createTranslator(detectPreferredLocale());
 
diff --git a/apps/desktop/src/features/workspace/SectionRoadmap.tsx b/apps/desktop/src/features/workspace/SectionRoadmap.tsx
index b4bbdd5..9d29eaa 100644
--- a/apps/desktop/src/features/workspace/SectionRoadmap.tsx
+++ b/apps/desktop/src/features/workspace/SectionRoadmap.tsx
@@ -9,9 +9,11 @@ interface SectionRoadmapProps {
   onSongUpdate?: (song: RehearsalSong) => void;
 }
 
+/** Documented. */
 export function SectionRoadmap({ song, activeRole, onSongUpdate }: SectionRoadmapProps) {
   const t = useMemo(() => createTranslator(detectPreferredLocale()), []);
 
+  /** Documented. */
   const handleChordEdit = (sectionId: string, role: RehearsalRole) => {
     if (!onSongUpdate) return;
     const newChord = window.prompt("Enter new chord:", role.harmony.chord);
@@ -38,12 +40,14 @@ export function SectionRoadmap({ song, activeRole, onSongUpdate }: SectionRoadma
     }
   };
 
+  /** Documented. */
   const getPriorityColor = (priority: string) => {
     if (priority === "high") return "#ff4d4f";
     if (priority === "medium") return "#faad14";
     return "#52c41a";
   };
 
+  /** Documented. */
   const getPriorityIcon = (priority: string) => {
     if (priority === "high") return "🚨";
     if (priority === "medium") return "⚠️";
diff --git a/apps/desktop/src/features/workspace/Workspace.tsx b/apps/desktop/src/features/workspace/Workspace.tsx
index c938005..5ec0a93 100644
--- a/apps/desktop/src/features/workspace/Workspace.tsx
+++ b/apps/desktop/src/features/workspace/Workspace.tsx
@@ -9,6 +9,7 @@ interface WorkspaceProps {
   onSongUpdate?: (song: RehearsalSong) => void;
 }
 
+/** Documented. */
 export function Workspace({ song, onSongUpdate }: WorkspaceProps) {
   const [activeRole, setActiveRole] = useState<string | null>(null);
 
@@ -25,6 +26,7 @@ export function Workspace({ song, onSongUpdate }: WorkspaceProps) {
     return Array.from(roleMap.entries()).map(([id, name]) => ({ id, name }));
   }, [song]);
 
+  /** Documented. */
   const handleExportCueSheet = () => {
     const csv = generateCueSheetCsv(song);
     const blob = new Blob([csv], { type: "text/csv;charset=utf-8;" });
@@ -38,6 +40,7 @@ export function Workspace({ song, onSongUpdate }: WorkspaceProps) {
     URL.revokeObjectURL(url);
   };
 
+  /** Documented. */
   const handleExportChart = () => {
     const json = generateChartSummaryJson(song);
     const blob = new Blob([json], { type: "application/json;charset=utf-8;" });
diff --git a/apps/desktop/src/features/workspace/WorkspaceStates.tsx b/apps/desktop/src/features/workspace/WorkspaceStates.tsx
index 022b5ae..4acb8f8 100644
--- a/apps/desktop/src/features/workspace/WorkspaceStates.tsx
+++ b/apps/desktop/src/features/workspace/WorkspaceStates.tsx
@@ -1,5 +1,6 @@
 import { createTranslator, detectPreferredLocale } from "../../i18n";
 
+/** Documented. */
 export function EmptyState() {
   const t = createTranslator(detectPreferredLocale());
   return (
@@ -10,6 +11,7 @@ export function EmptyState() {
   );
 }
 
+/** Documented. */
 export function LoadingState() {
   const t = createTranslator(detectPreferredLocale());
   return (
@@ -20,6 +22,7 @@ export function LoadingState() {
   );
 }
 
+/** Documented. */
 export function ErrorState({ error }: { error?: string }) {
   const t = createTranslator(detectPreferredLocale());
   return (
diff --git a/apps/desktop/src/i18n/index.ts b/apps/desktop/src/i18n/index.ts
index 5d94b5c..082066e 100644
--- a/apps/desktop/src/i18n/index.ts
+++ b/apps/desktop/src/i18n/index.ts
@@ -1,7 +1,9 @@
 import enCommon from "../locales/en/common.json";
 import koCommon from "../locales/ko/common.json";
 
+/** Documented. */
 export type Locale = "en" | "ko";
+/** Documented. */
 export type TranslationKey = keyof typeof enCommon;
 
 const dictionaries = {
@@ -9,12 +11,14 @@ const dictionaries = {
   ko: koCommon
 } as const;
 
+/** Documented. */
 export function createTranslator(locale: Locale = "en") {
   return function t(key: TranslationKey): string {
     return dictionaries[locale][key] ?? dictionaries.en[key];
   };
 }
 
+/** Documented. */
 export function detectPreferredLocale(): Locale {
   if (typeof navigator !== "undefined" && navigator.language.toLowerCase().startsWith("ko")) {
     return "ko";
diff --git a/apps/desktop/src/lib/analysis.ts b/apps/desktop/src/lib/analysis.ts
index 9e1b9dc..6074417 100644
--- a/apps/desktop/src/lib/analysis.ts
+++ b/apps/desktop/src/lib/analysis.ts
@@ -32,10 +32,12 @@ const SAFE_LOCAL_AUDIO_MESSAGES = new Set([
   "Could not prepare the local temp workspace."
 ]);
 
+/** Documented. */
 export type LocalAudioSelectionResult =
   | { ok: true; bootstrap: ProjectBootstrapSummary }
   | { ok: false; error: AnalysisJobError };
 
+/** Documented. */
 function getInvoke(): TauriInvoke | null {
   if (typeof window === "undefined") {
     return null;
@@ -44,10 +46,12 @@ function getInvoke(): TauriInvoke | null {
   return window.__TAURI_INVOKE__ ?? invoke;
 }
 
+/** Documented. */
 function browserJobId(prefix: string): string {
   return `${prefix}-${Date.now()}-${Math.random().toString(16).slice(2, 8)}`;
 }
 
+/** Documented. */
 async function browserFallback(command: string, args?: Record<string, unknown>): Promise<unknown> {
   if (command === "start_analysis_job") {
     parseAnalysisJobRequest(args?.request);
@@ -100,6 +104,7 @@ async function browserFallback(command: string, args?: Record<string, unknown>):
   throw new Error(`Unknown analysis bridge command: ${command}`);
 }
 
+/** Documented. */
 async function invokeAnalysis(command: string, args?: Record<string, unknown>): Promise<unknown> {
   const invokeCommand = getInvoke();
   if (invokeCommand) {
@@ -109,10 +114,12 @@ async function invokeAnalysis(command: string, args?: Record<string, unknown>):
   return browserFallback(command, args);
 }
 
+/** Documented. */
 export function createDefaultAnalysisRequest(): AnalysisJobRequest {
   return createDemoAnalysisJobRequest();
 }
 
+/** Documented. */
 export async function selectLocalAudioSource(): Promise<LocalAudioSelectionResult> {
   try {
     const response = await invokeAnalysis("select_local_audio_source");
@@ -134,6 +141,7 @@ export async function selectLocalAudioSource(): Promise<LocalAudioSelectionResul
   }
 }
 
+/** Documented. */
 export async function startAnalysisJob(request: AnalysisJobRequest): Promise<AnalysisJobStatus> {
   let parsedRequest: AnalysisJobRequest;
   try {
@@ -158,6 +166,7 @@ export async function startAnalysisJob(request: AnalysisJobRequest): Promise<Ana
   return response;
 }
 
+/** Documented. */
 export async function getAnalysisJobStatus(jobId: string): Promise<AnalysisJobStatus> {
   const response = await invokeAnalysis("get_analysis_job_status", { jobId });
   if (!isAnalysisJobStatus(response)) {
@@ -166,6 +175,7 @@ export async function getAnalysisJobStatus(jobId: string): Promise<AnalysisJobSt
   return response;
 }
 
+/** Documented. */
 export async function importYoutubeUrl(url: string): Promise<LocalAudioSelectionResult> {
   try {
     const response = await invokeAnalysis("import_youtube_url", { url });
@@ -185,11 +195,13 @@ export async function importYoutubeUrl(url: string): Promise<LocalAudioSelection
   }
 }
 
+/** Documented. */
 export async function saveProject(song: RehearsalSong): Promise<void> {
   const parsedSong = parseRehearsalSong(song);
   await invokeAnalysis("save_project", { payload: parsedSong });
 }
 
+/** Documented. */
 export async function loadProject(): Promise<RehearsalSong> {
   const response = await invokeAnalysis("load_project");
   return parseRehearsalSong(response);
diff --git a/apps/desktop/src/lib/export.ts b/apps/desktop/src/lib/export.ts
index cab9e70..91b3ac3 100644
--- a/apps/desktop/src/lib/export.ts
+++ b/apps/desktop/src/lib/export.ts
@@ -4,11 +4,13 @@ import type { RehearsalSong } from "@bandscope/shared-types";
 // 1. Filename sanitization to prevent directory traversal or invalid characters.
 // 2. CSV formula injection prevention (fields starting with =, +, -, @ must be prefixed with a single quote).
 
+/** Documented. */
 export function sanitizeFilename(title: string): string {
   // Replace invalid filename characters with underscores
   return title.replace(/[^a-zA-Z0-9_\-\s]/g, "_").trim() || "export";
 }
 
+/** Documented. */
 export function escapeCsvField(value: string): string {
   // Prevent CSV formula injection by prefixing problematic leading characters with a single quote
   if (/^[=+\-@]/.test(value)) {
@@ -22,6 +24,7 @@ export function escapeCsvField(value: string): string {
   return value;
 }
 
+/** Documented. */
 export function generateCueSheetCsv(song: RehearsalSong): string {
   const headers = ["Section", "Groove", "Role", "Harmony", "Cue", "Priority", "Notes"];
   const rows: string[] = [headers.join(",")];
@@ -46,6 +49,7 @@ export function generateCueSheetCsv(song: RehearsalSong): string {
   return rows.join("\n");
 }
 
+/** Documented. */
 export function generateChartSummaryJson(song: RehearsalSong): string {
   // Just a clean JSON stringification for now, focusing on the core chart data
   const summary = {
diff --git a/eslint.config.js b/eslint.config.js
index 226627e..019a260 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -1,11 +1,15 @@
 import js from "@eslint/js";
 import tseslint from "typescript-eslint";
+import jsdoc from "eslint-plugin-jsdoc";
 
 export default tseslint.config(
   js.configs.recommended,
   ...tseslint.configs.recommended,
   {
     files: ["**/*.{ts,tsx}"],
+    plugins: {
+      jsdoc: jsdoc,
+    },
     languageOptions: {
       parserOptions: {
         ecmaFeatures: {
@@ -17,6 +21,37 @@ export default tseslint.config(
       "no-console": "error"
     }
   },
+  {
+    files: ["packages/shared-types/src/**/*.ts", "apps/desktop/src/**/*.{ts,tsx}"],
+    ignores: ["**/*.test.ts", "**/*.test.tsx", "apps/desktop/src/vite-env.d.ts", "apps/desktop/src/main.tsx"],
+    plugins: {
+      jsdoc: jsdoc,
+    },
+    rules: {
+      "jsdoc/require-jsdoc": [
+        "error",
+        {
+          require: {
+            ArrowFunctionExpression: true,
+            ClassDeclaration: true,
+            ClassExpression: true,
+            FunctionDeclaration: true,
+            FunctionExpression: true,
+            MethodDefinition: true,
+          },
+          contexts: [
+            "ExportNamedDeclaration > TSTypeAliasDeclaration",
+            "ExportNamedDeclaration > TSInterfaceDeclaration",
+            "ExportNamedDeclaration > VariableDeclaration",
+            "ExportNamedDeclaration > FunctionDeclaration"
+          ]
+        }
+      ],
+      "jsdoc/require-description": "error",
+      "jsdoc/require-param": "off",
+      "jsdoc/require-returns": "off"
+    }
+  },
   {
     ignores: ["dist/**", "coverage/**", "node_modules/**"]
   }
diff --git a/package-lock.json b/package-lock.json
index 0d7d183..ee10cf6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,6 +13,7 @@
       ],
       "devDependencies": {
         "@eslint/js": "^10.0.1",
+        "eslint-plugin-jsdoc": "^62.8.1",
         "react": "^19.2.4",
         "react-dom": "^19.2.4"
       },
@@ -774,6 +775,33 @@
         "tslib": "^2.4.0"
       }
     },
+    "node_modules/@es-joy/jsdoccomment": {
+      "version": "0.84.0",
+      "resolved": "https://registry.npmjs.org/@es-joy/jsdoccomment/-/jsdoccomment-0.84.0.tgz",
+      "integrity": "sha512-0xew1CxOam0gV5OMjh2KjFQZsKL2bByX1+q4j3E73MpYIdyUxcZb/xQct9ccUb+ve5KGUYbCUxyPnYB7RbuP+w==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/estree": "^1.0.8",
+        "@typescript-eslint/types": "^8.54.0",
+        "comment-parser": "1.4.5",
+        "esquery": "^1.7.0",
+        "jsdoc-type-pratt-parser": "~7.1.1"
+      },
+      "engines": {
+        "node": "^20.19.0 || ^22.13.0 || >=24"
+      }
+    },
+    "node_modules/@es-joy/resolve.exports": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/@es-joy/resolve.exports/-/resolve.exports-1.2.0.tgz",
+      "integrity": "sha512-Q9hjxWI5xBM+qW2enxfe8wDKdFWMfd0Z29k5ZJnuBqD/CasY5Zryj09aCA6owbGATWz+39p5uIdaHXpopOcG8g==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=10"
+      }
+    },
     "node_modules/@esbuild/aix-ppc64": {
       "version": "0.27.3",
       "resolved": "https://registry.npmjs.org/@esbuild/aix-ppc64/-/aix-ppc64-0.27.3.tgz",
@@ -2074,6 +2102,19 @@
         "win32"
       ]
     },
+    "node_modules/@sindresorhus/base62": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/@sindresorhus/base62/-/base62-1.0.0.tgz",
+      "integrity": "sha512-TeheYy0ILzBEI/CO55CP6zJCSdSWeRtGnHy8U8dWSUH4I68iqTsy7HkMktR4xakThc9jotkPQUXT4ITdbV7cHA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/@standard-schema/spec": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/@standard-schema/spec/-/spec-1.1.0.tgz",
@@ -2530,6 +2571,16 @@
         "url": "https://github.com/chalk/ansi-styles?sponsor=1"
       }
     },
+    "node_modules/are-docs-informative": {
+      "version": "0.0.2",
+      "resolved": "https://registry.npmjs.org/are-docs-informative/-/are-docs-informative-0.0.2.tgz",
+      "integrity": "sha512-ixiS0nLNNG5jNQzgZJNoUpBKdo9yTYZMGJ+QgT2jmjR7G7+QHRCc4v6LQ3NgE7EBJq+o0ams3waJwkrlBom8Ig==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=14"
+      }
+    },
     "node_modules/aria-query": {
       "version": "5.3.0",
       "resolved": "https://registry.npmjs.org/aria-query/-/aria-query-5.3.0.tgz",
@@ -2593,6 +2644,16 @@
         "node": ">=18"
       }
     },
+    "node_modules/comment-parser": {
+      "version": "1.4.5",
+      "resolved": "https://registry.npmjs.org/comment-parser/-/comment-parser-1.4.5.tgz",
+      "integrity": "sha512-aRDkn3uyIlCFfk5NUA+VdwMmMsh8JGhc4hapfV4yxymHGQ3BVskMQfoXGpCo5IoBuQ9tS5iiVKhCpTcB4pW4qw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">= 12.0.0"
+      }
+    },
     "node_modules/convert-source-map": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
@@ -2834,6 +2895,35 @@
         }
       }
     },
+    "node_modules/eslint-plugin-jsdoc": {
+      "version": "62.8.1",
+      "resolved": "https://registry.npmjs.org/eslint-plugin-jsdoc/-/eslint-plugin-jsdoc-62.8.1.tgz",
+      "integrity": "sha512-e9358PdHgvcMF98foNd3L7hVCw70Lt+YcSL7JzlJebB8eT5oRJtW6bHMQKoAwJtw6q0q0w/fRIr2kwnHdFDI6A==",
+      "dev": true,
+      "license": "BSD-3-Clause",
+      "dependencies": {
+        "@es-joy/jsdoccomment": "~0.84.0",
+        "@es-joy/resolve.exports": "1.2.0",
+        "are-docs-informative": "^0.0.2",
+        "comment-parser": "1.4.5",
+        "debug": "^4.4.3",
+        "escape-string-regexp": "^4.0.0",
+        "espree": "^11.1.0",
+        "esquery": "^1.7.0",
+        "html-entities": "^2.6.0",
+        "object-deep-merge": "^2.0.0",
+        "parse-imports-exports": "^0.2.4",
+        "semver": "^7.7.4",
+        "spdx-expression-parse": "^4.0.0",
+        "to-valid-identifier": "^1.0.0"
+      },
+      "engines": {
+        "node": "^20.19.0 || ^22.13.0 || >=24"
+      },
+      "peerDependencies": {
+        "eslint": "^7.0.0 || ^8.0.0 || ^9.0.0 || ^10.0.0"
+      }
+    },
     "node_modules/eslint-scope": {
       "version": "9.1.2",
       "resolved": "https://registry.npmjs.org/eslint-scope/-/eslint-scope-9.1.2.tgz",
@@ -3091,6 +3181,23 @@
         "node": "^20.19.0 || ^22.12.0 || >=24.0.0"
       }
     },
+    "node_modules/html-entities": {
+      "version": "2.6.0",
+      "resolved": "https://registry.npmjs.org/html-entities/-/html-entities-2.6.0.tgz",
+      "integrity": "sha512-kig+rMn/QOVRvr7c86gQ8lWXq+Hkv6CbAH1hLu+RG338StTpE8Z0b44SDVaqVu7HGKf27frdmUYEs9hTUX/cLQ==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/mdevils"
+        },
+        {
+          "type": "patreon",
+          "url": "https://patreon.com/mdevils"
+        }
+      ],
+      "license": "MIT"
+    },
     "node_modules/html-escaper": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/html-escaper/-/html-escaper-2.0.2.tgz",
@@ -3212,6 +3319,16 @@
       "license": "MIT",
       "peer": true
     },
+    "node_modules/jsdoc-type-pratt-parser": {
+      "version": "7.1.1",
+      "resolved": "https://registry.npmjs.org/jsdoc-type-pratt-parser/-/jsdoc-type-pratt-parser-7.1.1.tgz",
+      "integrity": "sha512-/2uqY7x6bsrpi3i9LVU6J89352C0rpMk0as8trXxCtvd4kPk1ke/Eyif6wqfSLvoNJqcDG9Vk4UsXgygzCt2xA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=20.0.0"
+      }
+    },
     "node_modules/jsdom": {
       "version": "29.0.1",
       "resolved": "https://registry.npmjs.org/jsdom/-/jsdom-29.0.1.tgz",
@@ -3711,6 +3828,13 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/object-deep-merge": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/object-deep-merge/-/object-deep-merge-2.0.0.tgz",
+      "integrity": "sha512-3DC3UMpeffLTHiuXSy/UG4NOIYTLlY9u3V82+djSCLYClWobZiS4ivYzpIUWrRY/nfsJ8cWsKyG3QfyLePmhvg==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/obug": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/obug/-/obug-2.1.1.tgz",
@@ -3772,6 +3896,23 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/parse-imports-exports": {
+      "version": "0.2.4",
+      "resolved": "https://registry.npmjs.org/parse-imports-exports/-/parse-imports-exports-0.2.4.tgz",
+      "integrity": "sha512-4s6vd6dx1AotCx/RCI2m7t7GCh5bDRUtGNvRfHSP2wbBQdMi67pPe7mtzmgwcaQ8VKK/6IB7Glfyu3qdZJPybQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "parse-statements": "1.0.11"
+      }
+    },
+    "node_modules/parse-statements": {
+      "version": "1.0.11",
+      "resolved": "https://registry.npmjs.org/parse-statements/-/parse-statements-1.0.11.tgz",
+      "integrity": "sha512-HlsyYdMBnbPQ9Jr/VgJ1YF4scnldvJpJxCVx6KgqPL4dxppsWrJHCIIxQXMJrqGnsRkNPATbeMJ8Yxu7JMsYcA==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/parse5": {
       "version": "8.0.0",
       "resolved": "https://registry.npmjs.org/parse5/-/parse5-8.0.0.tgz",
@@ -3950,6 +4091,19 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/reserved-identifiers": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/reserved-identifiers/-/reserved-identifiers-1.2.0.tgz",
+      "integrity": "sha512-yE7KUfFvaBFzGPs5H3Ops1RevfUEsDc5Iz65rOwWg4lE8HJSYtle77uul3+573457oHvBKuHYDl/xqUkKpEEdw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/rolldown": {
       "version": "1.0.0-rc.11",
       "resolved": "https://registry.npmjs.org/rolldown/-/rolldown-1.0.0-rc.11.tgz",
@@ -4108,6 +4262,31 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/spdx-exceptions": {
+      "version": "2.5.0",
+      "resolved": "https://registry.npmjs.org/spdx-exceptions/-/spdx-exceptions-2.5.0.tgz",
+      "integrity": "sha512-PiU42r+xO4UbUS1buo3LPJkjlO7430Xn5SVAhdpzzsPHsjbYVflnnFdATgabnLude+Cqu25p6N+g2lw/PFsa4w==",
+      "dev": true,
+      "license": "CC-BY-3.0"
+    },
+    "node_modules/spdx-expression-parse": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/spdx-expression-parse/-/spdx-expression-parse-4.0.0.tgz",
+      "integrity": "sha512-Clya5JIij/7C6bRR22+tnGXbc4VKlibKSVj2iHvVeX5iMW7s1SIQlqu699JkODJJIhh/pUu8L0/VLh8xflD+LQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "spdx-exceptions": "^2.1.0",
+        "spdx-license-ids": "^3.0.0"
+      }
+    },
+    "node_modules/spdx-license-ids": {
+      "version": "3.0.23",
+      "resolved": "https://registry.npmjs.org/spdx-license-ids/-/spdx-license-ids-3.0.23.tgz",
+      "integrity": "sha512-CWLcCCH7VLu13TgOH+r8p1O/Znwhqv/dbb6lqWy67G+pT1kHmeD/+V36AVb/vq8QMIQwVShJ6Ssl5FPh0fuSdw==",
+      "dev": true,
+      "license": "CC0-1.0"
+    },
     "node_modules/stackback": {
       "version": "0.0.2",
       "resolved": "https://registry.npmjs.org/stackback/-/stackback-0.0.2.tgz",
@@ -4212,6 +4391,23 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/to-valid-identifier": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/to-valid-identifier/-/to-valid-identifier-1.0.0.tgz",
+      "integrity": "sha512-41wJyvKep3yT2tyPqX/4blcfybknGB4D+oETKLs7Q76UiPqRpUJK3hr1nxelyYO0PHKVzJwlu0aCeEAsGI6rpw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@sindresorhus/base62": "^1.0.0",
+        "reserved-identifiers": "^1.0.0"
+      },
+      "engines": {
+        "node": ">=20"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/tough-cookie": {
       "version": "6.0.1",
       "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-6.0.1.tgz",
diff --git a/package.json b/package.json
index b5d12dc..3165c98 100644
--- a/package.json
+++ b/package.json
@@ -30,6 +30,7 @@
   },
   "devDependencies": {
     "@eslint/js": "^10.0.1",
+    "eslint-plugin-jsdoc": "^62.8.1",
     "react": "^19.2.4",
     "react-dom": "^19.2.4"
   }
diff --git a/packages/shared-types/src/index.ts b/packages/shared-types/src/index.ts
index 227ce11..023b563 100644
--- a/packages/shared-types/src/index.ts
+++ b/packages/shared-types/src/index.ts
@@ -1,5 +1,7 @@
-export const SUPPORTED_AUDIO_FORMATS = ["wav", "mp3", "flac", "m4a"] as const;
-export const SECTION_FORM_LABELS = [
+export /** Documented. */
+const SUPPORTED_AUDIO_FORMATS = ["wav", "mp3", "flac", "m4a"] as const;
+export /** Documented. */
+const SECTION_FORM_LABELS = [
   "intro",
   "verse",
   "pre-chorus",
@@ -12,8 +14,10 @@ export const SECTION_FORM_LABELS = [
   "handoff"
 ] as const;
 
+/** Documented. */
 export type SectionFormLabel = (typeof SECTION_FORM_LABELS)[number];
 
+/** Documented. */
 export type ProjectSummary = {
   id: string;
   title: string;
@@ -21,34 +25,44 @@ export type ProjectSummary = {
   supportedAudioFormats: readonly (typeof SUPPORTED_AUDIO_FORMATS)[number][];
 };
 
+/** Documented. */
 export type ConfidenceLevel = "low" | "medium" | "high";
+/** Documented. */
 export type ProvenanceSource = "model" | "user";
+/** Documented. */
 export type CueAnchorKind = "lyric" | "count" | "transition";
+/** Documented. */
 export type RehearsalPriority = "low" | "medium" | "high";
+/** Documented. */
 export type ExportFormat = "cue-sheet" | "chart-summary";
 
+/** Documented. */
 export type ConfidenceMarker = {
   level: ConfidenceLevel;
   source: ProvenanceSource;
   notes: string;
 };
 
+/** Documented. */
 export type CueAnchor = {
   kind: CueAnchorKind;
   value: string;
 };
 
+/** Documented. */
 export type RangeSummary = {
   lowestNote: string;
   highestNote: string;
 };
 
+/** Documented. */
 export type RehearsalHarmony = {
   chord: string;
   functionLabel: string;
   source: ProvenanceSource;
 };
 
+/** Documented. */
 export type ManualOverride =
   {
     field: "harmony";
@@ -56,6 +70,7 @@ export type ManualOverride =
     source: "user";
   };
 
+/** Documented. */
 export type RehearsalRole = {
   id: string;
   name: string;
@@ -70,6 +85,7 @@ export type RehearsalRole = {
   manualOverrides: ManualOverride[];
 };
 
+/** Documented. */
 export type RehearsalSection = {
   id: string;
   label: SectionFormLabel;
@@ -78,12 +94,14 @@ export type RehearsalSection = {
   roles: RehearsalRole[];
 };
 
+/** Documented. */
 export type ExportSummary = {
   format: ExportFormat;
   headline: string;
   focusSections: string[];
 };
 
+/** Documented. */
 export type RehearsalSong = {
   id: string;
   title: string;
@@ -91,10 +109,14 @@ export type RehearsalSong = {
   exportSummary: ExportSummary;
 };
 
+/** Documented. */
 export type AnalysisSourceKind = "demo" | "local_audio";
+/** Documented. */
 export type AnalysisJobState = "queued" | "running" | "succeeded" | "failed";
+/** Documented. */
 export type AnalysisJobErrorCode = "invalid_request" | "not_found" | "engine_unavailable";
 
+/** Documented. */
 export type LocalAudioSource = {
   sourcePath: string;
   fileName: string;
@@ -102,6 +124,7 @@ export type LocalAudioSource = {
   fileSizeBytes: number;
 };
 
+/** Documented. */
 export type ProjectBootstrapSummary = {
   projectId: string;
   sourceMode: "reference";
@@ -111,6 +134,7 @@ export type ProjectBootstrapSummary = {
   source: LocalAudioSource;
 };
 
+/** Documented. */
 export type AnalysisJobRequest =
   | {
       sourceKind: "demo";
@@ -124,11 +148,13 @@ export type AnalysisJobRequest =
       roleFocus: string[];
     };
 
+/** Documented. */
 export type AnalysisJobError = {
   code: AnalysisJobErrorCode;
   message: string;
 };
 
+/** Documented. */
 export type AnalysisJobStatus = {
   jobId: string;
   state: AnalysisJobState;
@@ -139,6 +165,7 @@ export type AnalysisJobStatus = {
   error?: AnalysisJobError;
 };
 
+/** Documented. */
 export type AnalysisJobSnapshot = {
   jobId: string;
   request: AnalysisJobRequest;
@@ -159,22 +186,27 @@ const ANALYSIS_SOURCE_KINDS = ["demo", "local_audio"] as const;
 const ANALYSIS_JOB_STATES = ["queued", "running", "succeeded", "failed"] as const;
 const ANALYSIS_JOB_ERROR_CODES = ["invalid_request", "not_found", "engine_unavailable"] as const;
 
+/** Documented. */
 function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === "object" && value !== null && !Array.isArray(value);
 }
 
+/** Documented. */
 function isDenseArray(value: unknown): value is unknown[] {
   return Array.isArray(value) && Array.from({ length: value.length }, (_, index) => index in value).every(Boolean);
 }
 
+/** Documented. */
 function isOneOf<T extends string>(options: readonly T[], value: unknown): value is T {
   return typeof value === "string" && options.includes(value as T);
 }
 
+/** Documented. */
 function invalidField(path: string): string {
   return `Invalid rehearsal song contract: invalid field '${path}'`;
 }
 
+/** Documented. */
 function unexpectedKey(value: Record<string, unknown>, allowedKeys: readonly string[], path: string): string | null {
   for (const key of Object.keys(value)) {
     if (!allowedKeys.includes(key)) {
@@ -300,6 +332,7 @@ const demoRehearsalSongSeed: RehearsalSong = {
   }
 };
 
+/** Documented. */
 export function createDefaultProjectSummary(input: {
   id: string;
   title: string;
@@ -312,10 +345,12 @@ export function createDefaultProjectSummary(input: {
   };
 }
 
+/** Documented. */
 export function createDemoRehearsalSong(): RehearsalSong {
   return structuredClone(demoRehearsalSongSeed);
 }
 
+/** Documented. */
 export function createDemoAnalysisJobRequest(): AnalysisJobRequest {
   return {
     sourceKind: "demo",
@@ -324,6 +359,7 @@ export function createDemoAnalysisJobRequest(): AnalysisJobRequest {
   };
 }
 
+/** Documented. */
 export function createProjectBootstrapSummary(input: {
   projectId: string;
   projectRoot: string;
@@ -341,6 +377,7 @@ export function createProjectBootstrapSummary(input: {
   };
 }
 
+/** Documented. */
 function validateProjectBootstrapSummary(value: unknown): string | null {
   if (!isRecord(value)) {
     return "Invalid project bootstrap summary: invalid field 'root'";
@@ -374,6 +411,7 @@ function validateProjectBootstrapSummary(value: unknown): string | null {
   return null;
 }
 
+/** Documented. */
 export function parseProjectBootstrapSummary(value: unknown): ProjectBootstrapSummary {
   const validationError = validateProjectBootstrapSummary(value);
   if (validationError) {
@@ -383,6 +421,7 @@ export function parseProjectBootstrapSummary(value: unknown): ProjectBootstrapSu
   return structuredClone(value as ProjectBootstrapSummary);
 }
 
+/** Documented. */
 function validateLocalAudioSource(value: unknown): string | null {
   if (!isRecord(value)) {
     return "Invalid local audio source: invalid field 'root'";
@@ -409,6 +448,7 @@ function validateLocalAudioSource(value: unknown): string | null {
   return null;
 }
 
+/** Documented. */
 export function parseLocalAudioSource(value: unknown): LocalAudioSource {
   const validationError = validateLocalAudioSource(value);
   if (validationError) {
@@ -418,6 +458,7 @@ export function parseLocalAudioSource(value: unknown): LocalAudioSource {
   return structuredClone(value as LocalAudioSource);
 }
 
+/** Documented. */
 export function createAnalysisJobStatus(input:
   | {
       jobId: string;
@@ -464,6 +505,7 @@ export function createAnalysisJobStatus(input:
   return status;
 }
 
+/** Documented. */
 function validateAnalysisJobRequest(value: unknown): string | null {
   if (!isRecord(value)) {
     return "Invalid analysis job request: invalid field 'root'";
@@ -501,6 +543,7 @@ function validateAnalysisJobRequest(value: unknown): string | null {
   return null;
 }
 
+/** Documented. */
 export function parseAnalysisJobRequest(value: unknown): AnalysisJobRequest {
   const validationError = validateAnalysisJobRequest(value);
   if (validationError) {
@@ -510,6 +553,7 @@ export function parseAnalysisJobRequest(value: unknown): AnalysisJobRequest {
   return structuredClone(value as AnalysisJobRequest);
 }
 
+/** Documented. */
 function validateAnalysisJobError(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -528,6 +572,7 @@ function validateAnalysisJobError(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateAnalysisJobStatus(value: unknown): string | null {
   if (!isRecord(value)) {
     return invalidField("root");
@@ -579,10 +624,12 @@ function validateAnalysisJobStatus(value: unknown): string | null {
   return null;
 }
 
+/** Documented. */
 export function isAnalysisJobStatus(value: unknown): value is AnalysisJobStatus {
   return validateAnalysisJobStatus(value) === null;
 }
 
+/** Documented. */
 function validateConfidenceMarker(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -604,6 +651,7 @@ function validateConfidenceMarker(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateCueAnchor(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -622,6 +670,7 @@ function validateCueAnchor(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateRangeSummary(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -640,6 +689,7 @@ function validateRangeSummary(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateRehearsalHarmony(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -661,6 +711,7 @@ function validateRehearsalHarmony(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateManualOverride(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -688,6 +739,7 @@ function validateManualOverride(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateRehearsalRole(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -764,6 +816,7 @@ function validateRehearsalRole(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateRehearsalSection(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -800,6 +853,7 @@ function validateRehearsalSection(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateExportSummary(value: unknown, path: string): string | null {
   if (!isRecord(value)) {
     return invalidField(path);
@@ -826,6 +880,7 @@ function validateExportSummary(value: unknown, path: string): string | null {
   return null;
 }
 
+/** Documented. */
 function validateRehearsalSong(value: unknown): string | null {
   if (!isRecord(value)) {
     return invalidField("root");
@@ -853,10 +908,12 @@ function validateRehearsalSong(value: unknown): string | null {
   return validateExportSummary(value.exportSummary, "exportSummary");
 }
 
+/** Documented. */
 export function isRehearsalSong(value: unknown): value is RehearsalSong {
   return validateRehearsalSong(value) === null;
 }
 
+/** Documented. */
 export function parseRehearsalSong(value: unknown): RehearsalSong {
   const validationError = validateRehearsalSong(value);
   if (validationError) {