# share/sharedb

Realtime database backend based on Operational Transformation (OT)

Repository: https://github.com/share/sharedb
Canonical: https://ross.abutalabs.com/products/sharedb
Language: JavaScript
License: NOASSERTION
License Family: other
Last push: 2026-08-25T10:52:13+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 87, longevity 100
- inputs: {"age_days": 4902, "days_push": 8, "days_rel": 8, "gap_med": 49, "n_releases_24m": 8}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 6535, forks 457 (observed 2026-08-28T04:09:45.031327+00:00)

## What it is
ShareDB is a realtime database backend based on Operational Transformation (OT) for synchronizing JSON documents across clients. It supports concurrent multi-user collaboration, realtime query subscriptions, and integrates with any database via pub/sub for horizontal scaling.

## Use cases
- build collaborative document editors with realtime sync
- sync JSON state between multiple users in a web app
- implement multiplayer counters or leaderboards
- add offline change syncing that reconciles on reconnect
- track realtime user presence in an app

## When to choose
- you need concurrent multi-user editing of JSON documents with OT
- you want a database-agnostic realtime sync backend that scales horizontally
- you need historic document versions and presence syncing

## When to avoid
- you need CRDT-based conflict resolution instead of OT
- you want a turnkey hosted realtime service rather than a backend library
- your data model is not JSON documents

## Facets
- artifact type: library
- maturity: stable
- function: database, websocket, middleware, caching
- domain: databases, web-development, backend
- platform: browser, cross-platform
- tags: operational-transformation, collaborative-editing, realtime-sync, -documents, pubsub, real-time, nodejs

## Member repositories
- share/sharedb (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:45.031327+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:44:07.718290+00:00, confidence not recorded.
  - readme: https://github.com/share/sharedb (fetched 2026-08-28T04:09:45.031327+00:00, sha 6f3b239fc2c1)
  - registry_npm: https://registry.npmjs.org/sharedb (fetched 2026-08-29T08:40:41.414401+00:00, sha ddf61c9bb1f5)
- Data as of 2026-08-30T08:39:29.467469+00:00.