`, favicon, and body of `Root()` to\nmatch your app's existing `index.html`, and stamp anything else your shell\nreferences directly (images, css) with `immutableFileUrl()`.\n\n1. Create `frontend/root.tsx`:\n\n```tsx\n/** @jsxImportSource npm:hono@4/jsx */\nimport { raw } from \"npm:hono@4/html\";\nimport { immutableFileUrl } from \"https://esm.town/v/std/utils/index.ts\";\n\n// The HTML shell for the app. It is never cached, so immutableFileUrl can stamp\n// the current val version into each asset URL — the browser caches those\n// immutably, and publishing the val changes the URLs, refetching exactly once.\nexport function Root() {\n return (\n <>\n {raw(\"<!DOCTYPE html>\")}\n <html lang=\"en\">\n <head>\n <meta charSet=\"UTF-8\" />\n <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\" />\n <title>React Hono Val Town Starter

[{"_1":2,"_3":-5,"_4":-5},"loaderData",{"_5":6,"_7":8,"_9":10},"actionData","errors","root",{"_320":321,"_322":323},"routes/_app.x.$handle.$name",{"_11":12,"_13":14,"_15":-7,"_18":19,"_17":-7,"_240":-5,"_20":241,"_22":242,"_243":244,"_245":246,"_26":247,"_24":248,"_249":-5,"_250":-5,"_251":59,"_252":253,"_254":56,"_255":-5,"_256":-5,"_257":258},"routes/_app.x.$handle.$name.code.$",{"_11":12,"_13":14,"_15":16,"_17":-7,"_18":19,"_20":21,"_22":23,"_24":25,"_26":27,"_28":-5,"_29":-5,"_30":-5,"_31":-5,"_32":-5},"handle","test_account_001","name","guitar-lab","branchName","main","version","path","index.ts","project",{"_33":183,"_13":14,"_45":184,"_185":-5,"_186":59,"_187":188,"_189":188,"_190":191,"_192":-5,"_193":194,"_195":38,"_196":56,"_197":-5,"_198":-5,"_199":43,"_200":201,"_202":203,"_204":205,"_206":207,"_208":-5,"_209":210,"_211":210,"_212":213,"_214":213,"_215":213,"_216":210,"_217":210,"_218":219,"_220":221,"_222":223,"_224":59},"tree",[51,52,53,54],"file",{"_33":34,"_35":36,"_37":38,"_13":19,"_39":40,"_41":42,"_17":43,"_44":-5,"_45":46,"_47":48,"_49":14,"_18":50},"contents",[],"upstream","pull","ahead","behind","envVars","id","880e574a-09c0-49a4-a75e-cac9fd705d83","branchId","fe3da5af-30a0-482c-9cfe-bded055894d0","fileId","01a02aa4-dbb8-719f-bc43-19e2bc8208fe","content","import { parseVal, serveImmutableFile } from \"https://esm.town/v/std/utils/index.ts\";\nimport { Hono } from \"npm:hono\";\nimport { Root } from \"./frontend/root.tsx\";\n\nconst app = new Hono();\n\n// Serve the (never-cached) HTML shell at the root /\napp.get(\"/\", (c) => c.html(Root()));\n\n// Serve frontend files at the version-addressed URLs Root() stamps, cached immutably\napp.get(\"/__immutable/*\", (c) => serveImmutableFile(c.req.path));\n\n// View source redirect\napp.get(\"/source\", (c) => c.redirect(parseVal().links.self.val));\n\n// Add your API routes here\n// app.get(\"/api/data\", c => c.json({ hello: \"world\" }));\n\n// Unwrap and rethrow Hono errors as the original error\n// If you delete this, all errors will be \"Internal Server Error\"\napp.onError((err) => Promise.reject(err));\n\n// HTTP vals expect an exported \"fetch handler\"\n// This is how you \"run the server\" in Val Town with Hono\nexport default app.fetch;\n","fileType","http",0,"parentId","createdAt",["D",1787421842194],"branchVersion",1,"label",[19],{"_33":78,"_13":79,"_37":80,"_44":-5,"_35":36,"_47":48,"_55":56,"_45":81,"_17":43,"_41":82,"_39":-5,"_58":59,"_49":-5,"_60":83,"_18":84},{"_33":71,"_13":72,"_37":73,"_44":-5,"_35":36,"_47":48,"_55":56,"_45":74,"_17":43,"_41":24,"_39":75,"_58":59,"_49":-5,"_60":76,"_18":77},{"_33":63,"_13":64,"_37":65,"_44":-5,"_35":36,"_47":66,"_55":56,"_45":67,"_17":48,"_41":24,"_39":68,"_58":59,"_49":-5,"_60":69,"_18":70},{"_33":34,"_13":19,"_37":38,"_44":-5,"_35":36,"_47":48,"_55":56,"_45":57,"_17":43,"_41":42,"_39":40,"_58":59,"_49":14,"_60":61,"_18":62},"latest",true,["D",1787421842194],"deleted",false,"children",[],[19],"25b11362-17a0-4df7-b216-341ce700c92f","README.md","01a02aa4-dbb8-719f-bc43-17d83a46fa8b",22,["D",1787422030009],"# Guitar Lab 🎸\n\nA personal music theory & scales workbench — visualize any scale on the fretboard,\nwork through a structured curriculum, and drill your ear. Built for an intermediate\nguitarist whose main goal is scales and music theory.\n\n**Live:** https://guitar-lab.val.run\n\n## What's inside\n\n| Tab | What it does |\n| --- | --- |\n| **Lessons** | A 6-part curriculum (fretboard logic → intervals → major scale construction → pentatonics → modes → diatonic harmony), each with embedded live fretboard examples |\n| **Scale Lab** | Pick any root + one of 13 scales, see it color-coded across the whole neck. Toggle note names vs interval degrees (1, ♭3, 5…), and *hear* the scale ascend |\n| **Metronome** | Web-audio clicker, BPM 40–240, 3/4 · 4/4 · 6/4 time with accented beat one |\n| **Interval Trainer** | Ear-training game: hear two notes, name the interval, get instant feedback and a score |\n\n## Architecture\n\n```mermaid\ngraph LR\n Browser -->|\"GET /\"| Hono[\"index.ts (Hono server)\"]\n Hono -->|serves| Root[\"frontend/root.tsx (HTML shell)\"]\n Root -->|loads| Entry[\"frontend/index.tsx\"]\n Entry -->|renders| App[\"App.tsx (nav + layout)\"]\n App --> Lessons[\"Lessons.tsx\"]\n App --> Explorer[\"ScaleExplorer.tsx\"]\n App --> Metronome[\"Metronome.tsx\"]\n App --> Trainer[\"IntervalTrainer.tsx\"]\n Explorer --> Fretboard[\"Fretboard.tsx\"]\n Fretboard --> Theory[\"theory.ts (notes, scales, intervals, neck)\"]\n```\n\n## How it works\n\n- **`theory.ts`** is the engine — note names, interval labels, 13 scale formulas, and a\n fretboard grid builder. `mapScale()` colors every note on the neck by its scale degree.\n- **Client-side React** (no build step). Twind/Tailwind utilities for styling.\n- All audio is generated with the **Web Audio API** (oscillators) — no audio files.\n- Every frontend module is served at versioned URLs via `serveImmutableFile` and cached immutably.\n\n## Ideas for next iteration\n\n- A **chord explorer** (stack thirds off any scale degree to derive chords)\n- **Practice tracker** (habit streaks, saved to the val's SQLite + cron daily reminder)\n- **Note-to-fret finder** tool\n- Microphone pitch detection for real guitar input\n\n## File structure\n\n```\nfrontend/\n theory.ts Music theory + fretboard engine\n root.tsx HTML shell (stamps immutable asset URLs)\n index.tsx React entrypoint\n components/\n App.tsx Nav + layout\n Lessons.tsx 6-lesson curriculum\n ScaleExplorer.tsx Interactive root/scale explorer + audio\n Fretboard.tsx Neck renderer\n Metronome.tsx Web-audio clicker\n IntervalTrainer.tsx Ear-training quiz\n```\n",[],[64],"dbc48714-2533-466b-bc51-6d25e955f35e","CHANGELOG.md","01a02aa4-dbb8-719f-bc43-13e217c72655",["D",1787421842194],"# Changelog\n\n## 2026-07-30 — Immutable asset caching\n\nFrontend files are now served at version-addressed URLs\n(`/__immutable/45/frontend/index.tsx`) with\n`Cache-Control: public, max-age=31536000, immutable`, so repeat visits load the\nwhole client graph from the browser cache — roughly 3× faster (~665ms → ~157ms\nmeasured). Publishing your val bumps its version, which changes every URL, so\ncaches invalidate automatically. Old-version URLs return 404 after a publish\n(like Next.js build assets); a reload picks up the new version.\n\nWhat changed in the template:\n\n- `frontend/index.html` → [`frontend/root.tsx`](/frontend/root.tsx): the HTML\n shell is now JSX and stamps asset URLs with `immutableFileUrl()`\n- [`index.ts`](/index.ts): serves `Root()` at `/`, and one\n `app.get(\"/__immutable/*\", (c) => serveImmutableFile(c.req.path))` route\n serves all frontend files\n\n### Upgrading an existing remix\n\nYour copy of this template doesn't update automatically. Two options:\n\n**Minimal (most of the benefit):** point both routes at `serveImmutableFile` —\nyour existing bare URLs redirect into versioned space, the new route serves\nthem, and the whole module graph gets cached (costs one redirect per page view):\n\n```ts\nimport { serveImmutableFile } from \"https://esm.town/v/std/utils/index.ts\";\n\napp.get(\"/__immutable/*\", (c) => serveImmutableFile(c.req.path));\napp.get(\"/frontend/**/*\", (c) => serveImmutableFile(c.req.path)); // was serveFile\n```\n\n**Full upgrade (also removes the redirect):** three self-contained steps —\nno other files needed. Adjust the ``, favicon, and body of `Root()` to\nmatch your app's existing `index.html`, and stamp anything else your shell\nreferences directly (images, css) with `immutableFileUrl()`.\n\n1. Create `frontend/root.tsx`:\n\n```tsx\n/** @jsxImportSource npm:hono@4/jsx */\nimport { raw } from \"npm:hono@4/html\";\nimport { immutableFileUrl } from \"https://esm.town/v/std/utils/index.ts\";\n\n// The HTML shell for the app. It is never cached, so immutableFileUrl can stamp\n// the current val version into each asset URL — the browser caches those\n// immutably, and publishing the val changes the URLs, refetching exactly once.\nexport function Root() {\n return (\n <>\n {raw(\"<!DOCTYPE html>\")}\n <html lang=\"en\">\n <head>\n <meta charSet=\"UTF-8\" />\n <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\" />\n <title>React Hono Val Town Starter\n