Sutra

Your academic life, woven into one private workspace. One workspace. Every thread.

Sutra is a private, local-first workspace for students. It brings structured notes, homework, AP exam prep, college applications, spaced-repetition review, focus tools, calendar planning, and life and work trackers behind one calm interface — with no Sutra backend, no required account, and no telemetry. Optional Google Drive sync is off by default and uploads only browser-encrypted snapshots to the user's own Drive app-data folder.

If you can open an HTML file, you can run Sutra.

Eyebrow: PRIVATE · LOCAL-FIRST · STUDENT-BUILT. Built by Tanuj Ranjith.

Sutra was previously released as NoteFlow Atelier. It is the same workspace, rebranded. Your existing data loads automatically — see Rebrand & Compatibility. NoteFlow Classic is a separate legacy app and is not Sutra.

Table of Contents

1. What Sutra Is
2. Who It's For
3. Why the Name Sutra
4. Local-First Philosophy
5. Quick Start
6. Static-App Architecture
7. Product Map
8. Sutra Assistant & Sutra Intelligence
9. Themes, Customization, CSS Overrides, Plugins, Safe Mode
10. Backups & File Formats
11. Mobile & Tablet Behavior
12. Accessibility
13. Keyboard Shortcuts
14. Onboarding & Help
15. Privacy
16. Troubleshooting
17. Limitations
18. Release Checklist
19. License & Attribution

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What Sutra Is

Sutra is one app for everything a student carries:

• Notes — hierarchical pages, a rich editor with slash commands, Page Mode, document backgrounds, handwriting, split view, and templates.
• Planning — a Today command center with a Daily Thread, Shape My Day, a deterministic Next Step, Deadline Radar, and a full Timeline calendar.
• Homework — class and activity lanes, due-state tracking, and Import from School Portal.
• AP exam prep — units, sessions, practice logs, weak-area tracking, exam countdowns, an automated AP Battle Plan, and a Testing Hub.
• Review — spaced repetition and active recall with five study modes.
• College applications — trackers, essays, scholarships, scores, and decision matrices.
• Life — habits, sleep, journal, spending, goals, books, fitness, calories, and more.
• Projects & Work — a local operations dashboard for projects, clients, invoices, and deadlines.
• Focus — a Pomodoro-style Focus Timer with reusable templates, plus a writing-only Focus Mode.
• Sutra Assistant — an optional, bring-your-own-key AI panel that reads your workspace and proposes changes you approve one card at a time.

Everything is stored on your device by default. If you explicitly enable Google Drive sync, Sutra encrypts workspace snapshots in your browser before uploading them to your Drive app-data folder.

Who It's For

• High-school and college students juggling classes, AP exams, college apps, deadlines, extracurriculars, and a life.
• Self-directed writers and planners who want a Notion-style notebook without an account.
• Solo operators and freelancers who want a local CRM, invoice list, and deadline radar in the same workspace as their notes.
• Anyone who wants a single offline workspace they can carry between devices via one portable backup file.

Why the Name Sutra

Sutra is Sanskrit for a thread or string — the line that holds separate beads together into one piece. That is the whole idea: your notes, assignments, exams, deadlines, and reviews are usually scattered across apps and tabs. Sutra runs a single thread through them so they read as one continuous workspace instead of a pile of fragments.

We use the thread metaphor sparingly. Inside the app, labels stay literal — Today, Notes, Homework, Timeline. The thread is the spirit of the product, not a costume on every button.

Local-First Philosophy

• Local-first. Your workspace lives in browser storage on the device. No login. No telemetry. No required server.
• One surface, many modes. Sutra Modes promote the views you need now without deleting the others.
• Calm by default. Glass / neumorphic styling, configurable density, and a per-page theme system. Motion and contrast are tunable.
• Bring your own AI key. The Sutra Assistant is optional and uses a key you supply. Keys stay on this device for the session only and are never exported.
• Portable. A single password-encrypted .sutra file is a complete backup of your workspace.

Quick Start

1. Open Sutra.html directly (double-click is fine), or open the landing page HomePage.html and click Start your session. (index.html simply redirects to HomePage.html.)
2. On first launch, the Sutra Setup wizard offers to add your classes, AP subjects, college focus, and a Sutra Mode. Skip it if you prefer a blank slate.
3. Open Today to see the Daily Thread and one Next Step.
4. Press Ctrl/⌘+K to open the Command Palette and try Quick Capture, Create Weekly Review note, or Export backup.
5. Open Settings → Data and save a password-encrypted .sutra backup as soon as your workspace feels real.

For a full walkthrough, see the Sutra Guidebook.

Developers can use the built-in static server and Playwright matrix:

npm install
npm run serve
npm run check:all
npm run test:e2e

If your browser blocks some features under file:// (certain image-upload paths), serve the folder over HTTP with any static server — for example python -m http.server 5173, then visit http://localhost:5173/Sutra.html.

Static-App Architecture

Sutra is a plain static site. There is no backend, no build step, no bundler, and no required server. The page you open is the app.

Sutra/
├─ index.html            # Tiny redirect to HomePage.html
├─ HomePage.html         # Landing page with the thread scrollytelling + "Start your session"
├─ Sutra.html            # The app shell (views, modals, structural markup)
├─ manifest.webmanifest · sw.js   # PWA manifest + offline service worker
├─ assets/               # Brand logos (assets/brand/sutra/), favicon, marketing imagery, vendored JSZip
├─ styles/               # Stylesheets by cascade layer (see styles/README.md)
│  ├─ base/              # styles.css (core tokens/components/layout), microinteractions.css
│  ├─ themes/            # sutra-pro.css, glass.css, macos26-redesign.css
│  ├─ views/             # focus-session.css, settings-redesign.css
│  ├─ features/          # per-feature CSS (assistant, customization, notifications, academic, …)
│  ├─ responsive/        # mobile.css (loads late on purpose)
│  └─ legacy/            # large blocks externalized 1:1 from inline <style> in Sutra.html
├─ src/                  # Application source — classic scripts, no build (see src/README.md)
│  ├─ boot/              # startup-intro.js, sw-register.js
│  ├─ core/              # app.js (the global runtime) + safety layer (safe-storage, dom-safety, …)
│  ├─ state/             # workspace-normalizers.js (pure state, extracted from app.js)
│  ├─ config/            # sutra-runtime-config.js
│  ├─ features/          # assistant/ academic/ study/ customization/ workspace/ (see src/features/README.md)
│  ├─ ui/                # date/time/select enhancers
│  ├─ components/icons/  # icon path data + fallback patcher
│  └─ data/              # daily-lock-in-quotes.js, emoji-keywords.generated.js
├─ scripts/              # Node checks/build/probes + lib/ (flat; see scripts/README.md)
├─ tests/                # Playwright: e2e/ bench/ fixtures/ (see tests/README.md)
├─ docs/                 # architecture/ features/ privacy-security/ release/ archive/ (see docs/README.md)
├─ examples/plugins/     # Example plugin bundle
├─ noteflow-classic/   # The separate legacy app (NoteFlow Classic)
├─ LICENSE / NOTICE      # Apache License 2.0
└─ TRADEMARK.md          # Brand usage guidelines

The core runtime in src/core/app.js is a single large global-scope script — feature modules attach to it rather than importing it as a module. That is why the app opens straight from a file with no module resolver.

Heads-up for contributors: because app.js runs in global scope, top-level names live in one shared namespace. Watch for name collisions when adding new top-level functions or variables.

Renamed files (this release)

Old	New
NoteflowAtelier.html	Sutra.html
styles/atelier-pro.css	styles/themes/sutra-pro.css
scripts/atelier-persistence-qa.js	scripts/sutra-persistence-qa.js
docs/atelier-save-systems-audit.md	docs/architecture/sutra-save-systems-audit.md

Product Map

The top tab switcher exposes the workspace (visibility depends on the active Sutra Mode). All labels below are the literal names used in the app.

Today

The default landing experience — your daily command center.

• Daily Thread — overdue / today / tomorrow / this-week counts plus a deterministic Next Step you can run directly.
• Shape My Day — sequences your committed priorities against the calendar; the result appears under a Recommended sequence disclosure, and you can apply it back to the Timeline.
• Next Step — the single most useful action computed from your data, runnable in one click.
• Deadline Radar — a modal grouping every deadline (tasks, homework, AP exams, college, timeline blocks, work deadlines) by overdue / today / tomorrow / this week / later. Each row offers Open and Schedule this to convert it into a Timeline block.
• Quick Capture — a natural-language modal (from the Capture button or the Command Palette) that parses phrases like "Chem essay due Friday hard" into the right surface (task / homework / note / block / AP session / college item).
• Plus habits, a schedule snapshot, a completed-today strip, life signals, an academic planner, and Momentum (progress and analytics).

Timeline

A calendar planner with Month, Planner, Week, Day, and Year views; a time-block modal (name, start/end, category, color, recurrence, reference URL); a live Current Block card; a time-of-day surface tint; and ICS export/import. Schedule this actions across the app drop blocks here without retyping.

Notes

Sutra's writing surface.

• Page tree — hierarchical titles using :: (e.g. Projects::Website::Launch), with search, tag filter, drag-and-drop reordering, favorites, duplicate, rename, delete, emoji icons, and breadcrumbs. Temporary pages can self-expire. A built-in Help & Docs page always lives at the top of the tree.
• Rich editor — toolbar formatting (bold, italic, underline, strikethrough, H1–H3, lists, quote, code), an insert menu (link, table, image, video, audio, embed, checklist, collapsible section, page link), a slash menu (/), list indent with Tab / Shift+Tab, live word count, and configurable autosave.
• Page Mode — a document-style page presentation for the note surface.
• Document Backgrounds — a per-page background image set from the editor toolbar's Document Background button. Upload a .png, .jpg, .jpeg, or .webp (max 6 MB; large images auto-downscale), then tune a Background Blur slider (0–32 px) and a Dim Background slider (0–80%, default 25%). The dim overlay tints toward the editor surface so text stays readable in light, dark, and custom themes, and blur applies only to the image, never the text. Backgrounds work in the standard editor, Page Mode, split view, on mobile and tablet, and under custom CSS; they survive refresh, page duplication, and .sutra export/restore. Locked pages never show their background behind the PIN screen. See Document Backgrounds and CHANGELOG.
• Handwriting — insert a handwriting block to write, sketch, or annotate with mouse, trackpad, touch, or stylus (pen, highlighter, eraser; blank / lined / grid / dotted paper). Strokes are stored as vectors and round-trip through backups. Full guide: docs/features/HANDWRITING_AND_DRAWING.md.
• Split view — a second pane beside the current note, with split presets (Note + Assignment, Note + AP Unit, Essay + Research, Today Plan + Notes, Calendar + Note) and swap/close controls.
• Locked pages — PIN-protect any page (4–8 digits, stored as a salted SHA-256 hash, never as the raw PIN), with auto-lock options.

Homework

Two lanes — Subjects (your classes) and Activities (extracurriculars). Per-assignment fields cover title, due date/time, priority, difficulty, notes, and done state, with due-state chips (no date / upcoming / due soon ≤ 48 h / overdue). Import from School Portal pastes lines copied from a school portal (pipe-, tab-, or dash-separated), previews each parsed row, and lets you correct title / class / date / time / difficulty / priority before saving. JSON import/export is available, and each row's menu offers Schedule this and Open class dashboard. Any assignment can expand into an Assignment Studio (milestones, subtasks, rubric, linked notes/files, effort, revisions) whose milestones surface in All Due and Timeline — with Schedule remaining, Make focus plan, and Make review cards actions.

All Due

One cross-workspace command center for everything with a deadline (tasks, homework, assignment milestones, AP exams, review due, college deadlines, timeline blocks, work, plus workspace signals). Filter by overdue / today / this week / high-risk / unscheduled / review / AP / college / course / timeline, and sort by smart / due / urgency / importance / grade risk / effort / unscheduled-first / source. Every row explains why it's ranked here (one line from the same deterministic engine that powers Today's Next Step) and offers open source, schedule, start focus session, make review cards, open/create linked note, mark done, and defer. See All Due Command Center.

Course Hub

A central dashboard per class — overview, assignments, files, linked notes, linked review decks, schedule periods, teacher/contact, and grade forecast. The overview shows a deterministic "Do this next" card (top-ranked item + reason) for that course. Notes/decks/assignments link by reference (classLinkId / relationships / courseId), never duplicated. See Course Hub.

AP Study

Sections: Overview, Units, Sessions, Practice, Analytics. Subjects carry exam date/time, target score, confidence, teacher, current unit, notes, and an optional linked Homework class. Units track topics, status, and weak-area flags; sessions come in types (review, FRQ, MCQ, practice test, weak area, mixed); practice logs capture score, max score, minutes, confidence-after, and a weak marker. On the AP Study view, Ctrl/⌘+K is reserved for Add subject.

AP Battle Plan

A card at the top of AP Study that auto-picks the soonest exam, weighs weak units, recent practice, confidence, and days-left, and recommends a concrete next session with reasoning. From the card you can create a real AP session, create or open a linked AP unit note, log a task, or schedule a prep block on the Timeline.

Testing Hub

A dashboard-first exam-prep hub for pinned exams, with a per-exam calm overview built from test profiles and an integration with AP Study.

Cram

A focused Cram surface for last-minute sessions; the assistant can create Cram sessions on your approval.

Review

Sutra's spaced-repetition and active-recall center. It stores decks, review items (prompt + answer + tags), and review sessions, each card carrying scheduling state and graded Again / Hard / Good / Easy with a local SM-2-lite algorithm (no backend, no AI). Five study modes:

Mode	Description
Flashcards	Reveal the answer, then grade Again / Hard / Good / Easy.
Learn	Adaptive multiple-choice with mastery levels (new → learning → familiar → mastered).
Write	Type the answer; a fuzzy compare grades the attempt.
Test	Fixed-length mixed-format quiz with a final score and card-by-card review.
Match	Timed pair-up grid; best time is stored per deck.

Review surfaces a Review due card on Today, indexes deck names and card text in global search, links to a Focus template, and can take its source from a note, AP class, or homework class. The Review Generator turns existing work into cards: deterministic extraction (headings→body, term: definition lists, bold-term cloze) from a note, assignment, or All Due item, shown in an editable preview before saving, with each card linked back to its source. Start it from a note's menu (Generate review cards), Assignment Studio, All Due, or the Assistant. See Review Generator.

College

A dashboard with summary metrics (Application Completion %, Upcoming Deadlines, Scholarship Pipeline, SAT Countdown) and a grid into College Tracker, Essay Organizer, Score Tracker, Award/Honors Tracker, Scholarship Tracker, Decision Matrix, Major Deciding Matrix, and Application Sheets (Research, Checklist, Deadlines, Essay Plan, Essay Prompts). Rows with dates expose Schedule this; essay rows can open a draft note.

Life

A dashboard of primary trackers — Goals, Habits, Sleep, Spending, Journal — with a More Life Tools group for Skills, Fitness, Calories, Calculator, and Books.

Projects & Work

A local-first operations dashboard (formerly the Business / Freelancer workspace): Overview, Analytics, Projects, Opportunities, Clients, Invoices, Finance, Meetings, Tasks, Proposals/Contracts, Notes, Documents/Assets, and Goals/Targets, with KPI cards, a quick-actions strip, quick notes, and a deadlines aggregation that feeds the global Deadline Radar.

Focus

A compact Focus Timer in the sidebar (quick presets, custom durations, ringtones, alarm volume, a finish at preview, and reusable Focus Templates like Deep Work and AP Review that link a session to a subject, project, note, or deck). Focus Mode (Alt+Shift+F) is independent — it strips chrome from the writing surface for distraction-free writing.

Sutra Modes

Settings → Data chooses which views are primary. Hidden-by-mode views are never deleted — a view that already contains data stays reachable through the overflow menu.

Mode	Primary emphasis
All Tools	Everything visible.
Student	Today, Timeline, Notes, Homework, AP Study, College, Life.
AP Crunch	Today, AP Study, Homework, Timeline, Notes.
College Apps	Today, College, Notes, Timeline, Homework.
Writing	Notes, Today, Timeline.
Life	Today, Life, Notes, Timeline.
Projects & Work	Full operations dashboard.

Sutra Assistant & Sutra Intelligence

Sutra Assistant is the contextual chat panel — a mascot launcher at the bottom-right that opens a panel which can answer questions about your workspace and propose local changes (tasks, timeline blocks, notes, review cards, and more) that you approve one card at a time. It is optional and uses your own API key.

Sutra Intelligence is the local signal layer behind it. It reads only your workspace — overdue work, workload, schedule conflicts, weak areas, review backlog, and next steps — to ground the assistant's answers. It does not call any server itself.

Powered by Sutra Intelligence

A Powered by Sutra Intelligence badge sits directly under the panel header, with the subtitle "Local signals from your workspace." Hovering, tapping, or focusing it (the text is also the badge's aria-label) explains:

Sutra Intelligence analyzes local workspace signals such as overdue work, workload, schedule conflicts, weak areas, review backlog, and next steps. AI requests are sent only to the provider you choose.

How requests work

AI requests go directly from your browser to the provider you choose — Sutra runs no model servers and does not proxy anything. Supported providers:

• OpenAI
• Anthropic Claude
• Google Gemini
• Groq
• OpenRouter
• Custom OpenAI-Compatible Endpoint (a "Local endpoint")

You bring your own API key and the exact Model ID. Keys live in sessionStorage only (this browser session), are never exported, and are never included in Google Drive sync snapshots; when you send an Assistant request, the key is sent only to the provider you selected for that request.

Controls

• Workspace Access — Current Screen Only / Current Area / Full Workspace Context, plus selected-text awareness.
• Single Request vs Conversation Memory — whether the assistant remembers the thread.
• Suggested Changes — proposals render as Apply / Decline cards (with Apply all for multi-action replies); Confirm Before Applying Changes keeps approval in your hands. Replies also offer Insert into Note and Suggested Prompts.
• Assistant Activity — every applied action is logged locally with undo.

On mobile the panel fits the viewport, the composer stays usable with the software keyboard open, action cards stack, and the badge stays compact.

Themes, Customization, CSS Overrides, Plugins, Safe Mode

Apply any theme to the current page, all pages, or a custom subset (per-page theming). Built-in presets include Default, Dark, Botanical, Editorial, Luxury, Sepia, Ocean, Sunrise, Graphite, Aurora, Rosewater, macOS 26, Windows 11, ChromeOS, Ubuntu, GitHub, Spotify, Netflix, Slack, and Dune. You can create, edit, delete, import, and export custom themes, and set motion intensity to full / reduced / off (also tied to your OS prefers-reduced-motion).

Customization (Settings → Customization) is the power-user layer — everything local-first, no marketplace, traveling inside your workspace backup:

• CSS Overrides — multiple named snippets with enable/disable, live preview, brace-balance validation, duplicate, reorder, .css and JSON import/export, and a non-destructive reset. Custom CSS applies after themes and survives theme changes and refresh.
• Plugins — install local plugin bundles. Plugins are local bundles only (no marketplace), run sandboxed in an iframe behind an explicit permission allowlist, install disabled, and are reviewed before they run (forced on import). On import to a new device, runtime plugins return disabled and require re-review.
• Safe Mode — skip all custom CSS and plugins without deleting anything.

Guides: docs/features/MODS_AND_CUSTOMIZATION.md and docs/features/PLUGIN_SDK.md.

Safe Mode

Safe Mode loads Sutra with no custom CSS and no plugins — and never deletes data, CSS, plugins, or workspace. Enter it any of these ways:

• Add ?sutraSafeMode=1 to the URL (the legacy ?atelierSafeMode=1 still works).
• Hold Shift while the app loads.
• Use the in-app Recovery controls.

Backups & File Formats

.sutra (default)

.sutra is the default backup format — a complete, portable, password-encrypted copy of your workspace. Exports are named sutra_workspace_<YYYY-MM-DD>_<HH-mm-ss>.sutra using your local timezone (24-hour, zero-padded), so same-day exports never collide. A new .sutra file is a binary envelope with magic SUTRAENC, envelope version 1, a small authenticated JSON header, and AES-GCM ciphertext. The ciphertext contains the internal ZIP package with manifest.json, workspace.json, assets/, and metadata/ (export-summary.json, checksums.json). Renaming a new .sutra to .zip should not expose workspace contents.

The encrypted envelope uses PBKDF2-HMAC-SHA-256 with 600,000 iterations, a fresh 16-byte salt for manual exports, AES-GCM-256, a fresh 12-byte IV per export, and a 128-bit authentication tag. The encoded header is authenticated as AES-GCM additional data. Sutra cannot recover a forgotten backup password.

Inside the encrypted package, the manifest identifies Sutra:

{
  "product": "Sutra",
  "format": "sutra-workspace",
  "formatVersion": 1,
  "legacyCompatible": true,
  "appName": "Sutra"
}

Document backgrounds and inline note images ride along as internal assets/ files (with checksums) via recursive inline-asset extraction, so a background survives .sutra export -> wipe -> restore.

Legacy .atelier (still imports)

Old .atelier backups still import — the validator accepts both the new sutra-workspace manifest and the legacy noteflow_atelier_project manifest, and the import dispatcher routes both .sutra and .atelier files to the same package importer. Old backups are never broken.

Older unencrypted .sutra files also still import. Sutra warns that they are legacy plaintext backups, then runs them through the same package validation, checksum, asset rehydration, safety-snapshot, and atomic restore flow.

Optional Google Drive sync

Google Drive sync is optional and disabled by default. When enabled from Settings -> Data, Sutra requests only:

https://www.googleapis.com/auth/drive.appdata

Sutra stores one encrypted sync file named sutra-sync-current-v1.sutra in Drive's hidden appDataFolder. The browser storage remains the working copy. Drive failures never block local saving. The Drive sync password and derived key stay in memory only; the access token is also memory-only. The device-local sync metadata key (sutra:googleDriveSync:v1) is not included in .sutra backups or cloud snapshots.

To configure a hosted deployment, set the public OAuth Web Client ID in src/config/sutra-runtime-config.js or by defining window.SUTRA_CONFIG.googleDriveClientId before src/core/app.js loads. Do not put client secrets, tokens, or passwords in static files. See docs/features/GOOGLE_DRIVE_SYNC_SETUP.md.

Plugins: .sutra-plugin (new) and .atelier-plugin (still imports)

.sutra-plugin is the new plugin export extension. Legacy .atelier-plugin bundles still import. (The bundled example, examples/plugins/study-helper.atelier-plugin, uses the legacy extension and imports fine.)

Never exported

API keys, provider credentials, tokens, backup passwords, cloud-sync passwords, and derived keys are never written into any backup. The assistant activity log (key sutra:activityLog:v1, migrated from the legacy flow:activityLog:v1) is not a secret and travels in backups.

Internal storage names

For compatibility, Sutra intentionally retains its legacy internal identifiers so existing browser data keeps loading: IndexedDB databases noteflow_atelier_db (workspace) and noteflow_attachments_db (course/file binaries), plus the localStorage mirrors hwCourses:v2 / hwTasks:v2. Treat these as legacy-named compatibility identifiers — the names are historical, not a sign that anything still calls itself "Atelier." Full detail in Rebrand & Compatibility.

Mobile & Tablet Behavior

Sutra is responsive from 1440 px down to 320 px. Breakpoints in styles/responsive/mobile.css cover large tablet (1024 px), small tablet (768 px), and phone (640 px).

• The sidebar collapses behind a toggle and a tap-overlay; the pages list scrolls inside the drawer.
• The top tab strip becomes a single current view dropdown that expands the full list; overflowing tabs move into a More menu.
• Modals scroll internally and keep their primary actions visible above mobile browser chrome; under 640 px they stack to a single column.
• Settings → Accessibility → Larger touch targets enlarges interactive elements for thumb use.

Accessibility

• Keyboard navigation throughout, with visible focus and ARIA labels.
• Reduced-motion and JavaScript-disabled fallbacks (the landing thread shows its final connected state with no pinned dead zones).
• Readable at 200% zoom, with attention to color contrast.
• Large touch targets — at least 44 px for primary controls (40 px where space is constrained).

Keyboard Shortcuts

Sutra is keyboard-first. The most important shortcut is the Command Palette (Ctrl/⌘+K) — type to filter, arrow to navigate, Enter to run, Esc to close. From it you can jump to any view, run Quick Capture, export a backup, create a Weekly Review note, restart onboarding, open a class dashboard, and more.

Shortcut	Action
Ctrl/⌘+K	Command Palette (on AP Study, this is Add subject instead).
Shift+Ctrl/⌘+F	Global Search across Notes, Tasks, Homework, AP Study, Review, trackers, College, and Timeline.
Alt+Shift+F	Toggle Focus Mode.
Ctrl/⌘+Shift+M	Toggle the markdown shortcut on the current selection (where supported).
Tab / Shift+Tab	Indent / outdent list items in the editor.
/ (in editor)	Open the slash command menu.

Onboarding & Help

Sutra ships layered help:

1. Sutra Setup — the first-launch wizard that adds classes, AP subjects, and college focus, picks a Sutra Mode, and offers an immediate .sutra backup. Restart it anytime from Settings → Advanced → Restart Sutra Setup.
2. Starter Packs — local, preview-then-apply workspace seeds (notes, courses, review decks, timeline blocks, tasks) for goals like AP season, college apps, SAT/ACT, robotics, senior year, research, freelancing, or a personal life system. Apply all or selected parts, with one-tap undo. Open from Settings → Integrations → Starter Packs or the All Due empty state. See Starter Packs.
3. Help & Docs page — an auto-generated, non-removable page at the top of the page tree, with its own table of contents.
4. Interactive tutorial — a guided overlay tour from Settings → Advanced.

A long-form written tutorial lives in the Sutra Guidebook.

Privacy

• Storage is local-first on this device: IndexedDB holds the workspace; localStorage holds settings, health state, and a few caches.
• There is no Sutra-operated server. Fresh startup, manual encrypted .sutra backup, and JSON backup are designed to make zero third-party requests.
• Optional outbound calls happen only when you trigger them: Google Drive OAuth/sync, Sutra Assistant provider requests, approved feedback-form embeds, approved media embeds (YouTube, Vimeo, Spotify, SoundCloud, CodePen, Figma, and YouTube thumbnails), AP Classroom resource links, AI-console help links, ChatGPT/Spotify launch shortcuts, configurable localhost/127.0.0.1 AI endpoints, and secondary document import/export libraries when a browser-native fallback is not enough.
• API keys never leave sessionStorage and are never exported.
• New .sutra exports are password-encrypted. JSON exports and document exports are not encrypted. Locked-page PINs protect a page within the browser UI (hashed credentials travel in backups), which is not full-disk encryption.
• Clearing browser storage without a backup will lose your local data.

Troubleshooting

• App won't open from index.html — it redirects to HomePage.html. If your browser blocks the redirect, open HomePage.html or Sutra.html directly.
• A custom CSS snippet or plugin broke the UI — load Safe Mode (?sutraSafeMode=1, hold Shift at load, or the in-app Recovery button) and disable the offending snippet/plugin. Nothing is deleted.
• Sutra Assistant returns 401 / model errors — re-check the API key for the active provider and the exact Model ID. A wrong Model ID fails at the provider, not in Sutra.
• An imported backup looks wrong - a pre-import safety snapshot is written before every workspace import; restore it from Settings -> Data -> Storage Health.
• Tabs are missing — check Settings → Advanced → Feature Tabs and the active Sutra Mode. Hidden-by-mode tabs with data still appear under the overflow menu.
• Fonts look different offline - external web fonts are not requested on startup. Sutra uses local/system fallbacks unless you explicitly host or allow additional font assets.

Limitations

• Cloud sync is optional and foreground-only. Google Drive sync runs while Sutra is open, online, unlocked, and authorized. It does not sync after the browser is fully closed, and direct file:// launch may not support Google OAuth.
• Browser storage caps. IndexedDB and localStorage quotas vary by browser; very large, media-rich workspaces can hit limits. Export .sutra regularly.
• Document export is native and offline. PDF uses the browser print pipeline (opens a print-ready view — choose Save as PDF); the Word option exports a full-page Word-compatible .doc; HTML, Markdown, RTF, and TXT are produced locally with no third-party library. PDF can render slightly differently across browsers. See Document Export.
• External media embeds depend on the source's CORS / iframe policy and the approved-origin CSP list.
• Sutra Assistant Model IDs must match the provider's exact string; typos fail at the provider.
• file:// sandboxing — some image-upload paths need an http(s):// origin; use a static server if you hit this.
• Document backgrounds in document exports — HTML export includes the background where feasible and PDF preserves it where browser printing allows; Markdown and plain text omit it cleanly. DOCX/RTF background support is not reliably available and is treated as a known limitation.

Release Checklist

The canonical pre-release checklist lives at docs/release/TESTING_AND_RELEASE_CHECKLIST.md. The repository ships Node-based guards you can run with no dependencies:

node scripts/smoke-check.mjs            # structural assertions across the app
node scripts/round-trip-check.mjs       # backup export → import fidelity
node scripts/version-history-check.mjs  # note version history
node scripts/sutra-docbg-check.mjs      # document-background data model + export
node scripts/sutra-brand-assets-check.mjs  # brand logos, favicon, derivatives + references
npm run check:csp                       # CSP/static network policy guard
npm run check:persistence               # centralized persistence-health guard
npm run check:modal                     # modal accessibility primitive guard
npm run check:network                   # approved-origin/CDN guard
npm run test:e2e                        # Chromium, Firefox, WebKit Playwright matrix

Brand icons are generated from two canonical master PNGs (assets/brand/sutra/) with python scripts/generate-sutra-brand-assets.py (requires Pillow). Full reference: docs/features/BRAND_ASSETS.md.

Per the release process, the suite also includes rebrand and responsive guards (scripts/sutra-rebrand-check.mjs, scripts/sutra-responsive-check.mjs) and a node --check syntax pass over each src JS file. A browser QA harness is provided at scripts/sutra-persistence-qa.js.

License & Attribution

Sutra is licensed under the Apache License 2.0. See LICENSE and NOTICE for the full terms.

You may use, modify, and distribute this project under Apache 2.0. When redistributing or building derivative works, please retain the LICENSE and NOTICE files in full, clearly indicate that your version has been modified, and use the recommended attribution phrase: "Based on Sutra by Tanuj Ranjith." (Sutra was formerly NoteFlow Atelier; the legacy attribution phrase remains accurate for older forks.)

The Sutra name, logo, and official branding should not be used in a way that implies endorsement or official affiliation with the original project. See TRADEMARK.md for brand usage guidelines.

NoteFlow Classic is a separate legacy app that lives under noteflow-classic/. It is not Sutra and is maintained independently.

Copyright 2026 Tanuj Ranjith.