# soundcloud/roshi

Roshi is a large-scale CRDT set implementation for timestamped events.

Repository: https://github.com/soundcloud/roshi
Canonical: https://ross.abutalabs.com/products/roshi
Language: Go
License: BSD-2-Clause
License Family: permissive
Last push: 2026-08-21T06:42:39+00:00

## Health v2 (maintenance only)
Score: 76/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 98, release rhythm 35, longevity 100
- inputs: {"age_days": 4614, "days_push": 12, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3180, forks 155 (observed 2026-08-28T04:07:47.792329+00:00)

## What it is
Roshi is a distributed CRDT set implementation for timestamped events, built in Go as a stateless layer on top of sharded Redis clusters. It implements a LWW-element-set with limited inline garbage collection, providing fault tolerance via duplicated clusters without consensus protocols.

## Use cases
- store timestamped event streams at scale
- build a high-performance index for time-series data
- implement activity feeds like a social stream
- achieve eventual consistency without consensus protocols
- shard datasets across multiple Redis instances with fault tolerance

## When to choose
- you need a highly available, partition-tolerant store for timestamped sets in the request path
- you want CRDT semantics to avoid running a consensus protocol
- your dataset is too large for a single Redis instance and needs sharding plus replication

## When to avoid
- you need strong consistency or transactions rather than eventual consistency
- your data model needs rich queries beyond ordered set selection by key
- you don't already operate Redis infrastructure and multiple clusters

## Facets
- artifact type: library
- maturity: maintenance
- function: database, caching, concurrency
- domain: databases, microservices
- platform: go
- tags: crdt, lww-element-set, redis, timestamped-events, event-stream, eventual-consistency, real-time, linux, macos

## Member repositories
- soundcloud/roshi (main) score 76

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:47.792329+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 2026-08-30T07:25:05.668718+00:00, confidence not recorded.
  - readme: https://github.com/soundcloud/roshi (fetched 2026-08-28T04:07:47.792329+00:00, sha ac825f4d4503)
- Data as of 2026-08-30T08:39:29.467469+00:00.