Zero (Rocicorp)
activeby Rocicorp · since 2024 · also known as Zero, Zero Sync, zero-cache
Query-driven sync engine: clients run ZQL locally against a Postgres-backed cache for instant UIs.
Overview
Zero is a sync engine from Rocicorp, the makers of Replicache. A zero-cache server replicates your PostgreSQL database into SQLite and keeps client-side caches up to date. Clients write ZQL queries (relational, with nested relationships) that answer instantly from local data and are kept live by incremental view maintenance on the server. Writes are custom mutators that run optimistically on the client and authoritatively in a Postgres transaction on your server. Zero reached 1.0 and is under very active development. It is aimed at snappy web apps like Linear-style tools rather than offline-for-days mobile apps.
Strengths & trade-offs
Strengths
- +Relational queries with nested relationships answered from local cache
- +Incremental view maintenance keeps many live queries cheap
- +Uses your existing Postgres as the source of truth
- +Custom mutators keep server-side validation in normal code
Trade-offs
- −Not designed for long offline write sessions
- −You operate zero-cache yourself; no first-party managed service
- −TypeScript/web focus; native mobile SDKs are limited
Great for
- +Highly interactive SaaS web apps (issue trackers, editors, dashboards)
- +Adding instant UI updates over an existing Postgres schema
- +Replacing Replicache in existing apps
Think twice for
- −Offline-first mobile apps
- −Non-Postgres backends
- −Analytics queries
Capabilities
Native or official first-party support · 3 of 25 tracked
Scale & consistency
- Comfortable data size
- Medium · ≤ 10 TB
- Horizontal scaling
- Manual
- Multi-region
- No
- Transactions
- Full ACID
- Consistency
- Causal
- Schema
- Strict
- Architecture
- Client server
- Query languages
- ZQL
zero-cache supports multiple view-syncer nodes; write capacity is that of the upstream Postgres.
Deployment
Ecosystem
Alternatives to Zero (Rocicorp)
Client-side sync framework for instant web UIs; now free, open source and in maintenance mode.
rocicorp-zero vs replicache →Read-path sync engine that streams partial replicas of Postgres to clients over plain HTTP.
rocicorp-zero vs electricsql →Sync engine that keeps on-device SQLite in sync with Postgres, MongoDB, MySQL or SQL Server.
rocicorp-zero vs powersync →Realtime client-side database with relational queries, auth and permissions; cloud sunsets in 2027.
rocicorp-zero vs instantdb →Reactive TypeScript backend with a transactional document database, server functions and live queries.
rocicorp-zero vs convex →Local-first database with built-in sync, permissions and edit history, being rebuilt as a relational Jazz 2.
rocicorp-zero vs jazz →Zero (Rocicorp) FAQ
What is Zero (Rocicorp)?
Zero (Rocicorp) is a relational database by Rocicorp, first released in 2024. Zero is a sync engine from Rocicorp, the makers of Replicache. A zero-cache server replicates your PostgreSQL database into SQLite and keeps client-side caches up to date. Clients write ZQL queries (relational, with nested relationships) that answer instantly from local data and are kept live by incremental view maintenance on the server. Writes are custom mutators that run optimistically on the client and authoritatively in a Postgres transaction on your server. Zero reached 1.0 and is under very active development. It is aimed at snappy web apps like Linear-style tools rather than offline-for-days mobile apps.
Is Zero (Rocicorp) open source?
Yes. Zero (Rocicorp) is open source. License: Apache License 2.0.
Does Zero (Rocicorp) support ACID transactions?
Yes. Zero (Rocicorp) supports full ACID transactions, with causal consistency.
Does Zero (Rocicorp) scale horizontally?
Zero (Rocicorp) has no built-in sharding; scaling out means partitioning data in your application. It is comfortable at medium scale (≤ 10 TB).
How can I run Zero (Rocicorp)?
You can self-host it.
What is Zero (Rocicorp) best for?
Zero (Rocicorp) is a strong fit for highly interactive SaaS web apps (issue trackers, editors, dashboards); adding instant UI updates over an existing Postgres schema; and replacing Replicache in existing apps. Think twice for offline-first mobile apps.
What are the best alternatives to Zero (Rocicorp)?
Common alternatives to Zero (Rocicorp) include Replicache, ElectricSQL, PowerSync, InstantDB and Convex. The right choice depends on your workload, scale and hosting; WhichDB's smart match ranks them against your requirements.
How popular is Zero (Rocicorp)?
Zero (Rocicorp) ranks #149 of 844 databases on the WhichDB Score (20.8/100), and #48 among relational databases. The score combines public adoption signals such as package downloads, GitHub activity, job posts and developer discussion.