PebblesReal-time spreadsheet infrastructure

Collaborative sheets with instant local edits, durable sync, and formulas kept off the UI thread.

Pebbles is a lightweight collaborative spreadsheet with live sync, durable rooms, and worker-backed formulas.

Grid scale

1M logical cells

Sparse storage and viewport virtualization.

Sync path

BroadcastChannel + WebSocket

Fast local tabs and cross-device collaboration.

Computation

Worker-backed formulas

Computed values stay off the main UI thread.

Document flow

Edits apply locally, sync across tabs, then converge in the shared room.

Yjs stores authored cell input.
Durable Objects persist metadata and rooms.
Firebase Auth establishes identity.
The editor renders only the visible grid.
01

Capture

Raw cell input is stored in the shared Yjs map.

02

Evaluate

HyperFormula recomputes off the main thread.

03

Persist

Room state is kept durable for clean recovery.