Yapper

Shared notes you write together, in real time — and can take back with one click.

Yapper is a collaborative rich-text note app. Several people edit the same note at once and see each other's live cursors. The owner shares a note with a secret link, decides whether people can view or edit, and can flip it back to private at any moment — everyone else is disconnected instantly.

What you get

• Write together, live. Multiple cursors, real names, no "who has the file open?"
• Share with a link. Anyone opening it still has to log in with Google or GitHub — no anonymous guests.
• One switch for access. private → view → edit, set by the owner, applies to everyone on the note.
• Take it back instantly. Going private rotates the link, revokes collaborators, and kicks every other editor with "note made private by owner." The owner stays put.
• Fast, even offline. Notes are stored on-device and render instantly; edits keep working with no connection and sync when you're back.

Why not just use a normal note app?

Sharing usually means picking between a public link anyone can forward, or a permission system that's a chore to manage. Yapper keeps it simple: a link to share, a real identity behind every cursor, and one switch to pull the note back to private with nothing left lingering.

Tech stack

• Monorepo: Turborepo + Bun workspaces — three apps (web, api, socket) plus shared packages (db, auth, editor, permissions, schemas, typescript-config)
• Web: Next.js, TypeScript (strict), Tailwind CSS + shadcn/ui (Radix), TanStack Query (server state), Zustand (UI state), Motion (animation), TipTap editor, Yjs + @hocuspocus/provider
• Local-first: Dexie (IndexedDB) working set, client-minted note ids, push/pull sync engine over REST + SSE (Redis poke), service worker for the offline app shell
• API: Bun + Express, Better Auth handler, notes & sharing REST, sync push/pull endpoints, note metadata + collaborator records
• Socket: Bun + Hocuspocus (Yjs WebSocket backend), Redis extensions for cross-instance fanout and persistence
• Data & realtime: PostgreSQL + Drizzle ORM, Redis (Yjs fanout, revoke broadcast, permissions cache), Yjs CRDT
• Auth: Better Auth (Google + GitHub OAuth, JWT/JWKS — socket verifies the handshake statelessly)
• Validation: Zod schemas shared across web/api/socket via @yapper/schemas — one contract per boundary
• Tooling: Biome (lint + format), Vitest (unit tests)

Getting started

bun install
bun run dev      # boots web, api, and socket via Turborepo

Each app reads its config from a local .env (see each app's .env.example) — you'll need a Postgres URL and a Redis URL (hosted or local) plus Google/GitHub OAuth credentials.

Quality gates: bun run check (Biome), bun run check-types, bun run test. Per-app tests: bun run test:web, test:api, test:socket, test:db.