# nisshi-io/nisshi

Apache Kafka® compatible broker with S3, PostgreSQL, SQLite, Apache Iceberg and Delta Lake

Repository: https://github.com/nisshi-io/nisshi
Canonical: https://ross.abutalabs.com/products/nisshi
Homepage: https://docs.nisshi.io
Language: Rust
License: Apache-2.0
License Family: permissive
Topics: built-with-rust, postgres, postgresql, s3, apache-iceberg, apache-kafka, apache-arrow, datafusion, parquet, delta-lake, datalake, sqlite
Last push: 2026-08-26T06:44:55+00:00

## Health v2 (maintenance only)
Score: 88/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 95, longevity 53
- inputs: {"age_days": 742, "days_push": 7, "days_rel": 33, "gap_med": 5, "n_releases_24m": 28}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1851, forks 76 (observed 2026-08-28T04:05:44.385765+00:00)

## What it is
Nisshi is a stateless, Kafka API-compatible message broker written in async Rust with pluggable storage engines (PostgreSQL, SQLite/libSQL, S3, or memory). It includes an embedded schema registry (Avro, JSON Schema, Protobuf) and can write schema-backed topics as Apache Iceberg or Delta Lake tables.

## Use cases
- run a kafka-compatible message broker without zookeeper or raft consensus
- store kafka topic data in s3 or postgresql instead of replicated broker storage
- validate avro, json, or protobuf messages against schemas at produce time
- stream kafka topics into apache iceberg or delta lake tables
- spin up an ephemeral in-memory kafka broker for testing
- migrate off apache kafka without rewriting kafka clients

## When to choose
- you want kafka API compatibility with cheaper, simpler durability via S3 or PostgreSQL
- you need schema validation and a schema registry built into the broker
- you want topic data landing directly in Iceberg or Delta Lake for analytics
- you prefer a single statically linked binary with no cluster coordination overhead

## When to avoid
- you need battle-tested, large-scale Kafka ecosystem features like Kafka Connect, Streams, or tiered storage parity
- you require broker-side replication semantics and in-sync replicas for strict durability guarantees
- your tooling depends on Kafka-specific protocols beyond the core client API
- you need a mature project - it is relatively young with a small download base

## Facets
- artifact type: service
- maturity: active
- function: message-queue, streaming, serialization, database, object-storage, cli, proxy
- domain: big-data, databases, developer-tools, self-hosted
- platform: rust, self-hosted, cloud
- tags: kafka-compatible, apache-iceberg, delta-lake, schema-registry, avro, protobuf, s3-storage, stateless-broker, parquet, apache-arrow, messaging, data-engineering, linux, macos, docker

## Member repositories
- nisshi-io/nisshi (main) score 88

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:44.385765+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 2026-08-30T03:16:55.977626+00:00, confidence not recorded.
  - readme: https://github.com/nisshi-io/nisshi (fetched 2026-08-28T04:05:44.385765+00:00, sha 6355914491b4)
  - homepage: https://docs.nisshi.io (fetched 2026-08-29T10:56:19.216231+00:00, sha 5f169f30bc02)
  - site_page: https://docs.nisshi.io/docs/features (fetched 2026-08-29T10:56:19.219259+00:00, sha 4244827e0b5a)
  - site_page: https://docs.nisshi.io/docs/installation (fetched 2026-08-29T10:56:19.221412+00:00, sha e7dee960755c)
  - site_page: https://docs.nisshi.io/docs/build (fetched 2026-08-29T10:56:19.223315+00:00, sha 3d44a082b002)
  - site_page: https://docs.nisshi.io/docs/storage-engine (fetched 2026-08-29T10:56:19.225226+00:00, sha e6da70f2fcc1)
  - site_page: https://docs.nisshi.io/docs/stateless-brokers (fetched 2026-08-29T10:56:19.227107+00:00, sha c2df48566fec)
  - site_page: https://docs.nisshi.io/docs/schema-registry (fetched 2026-08-29T10:56:19.229328+00:00, sha ec3a1c052993)
  - site_page: https://docs.nisshi.io/docs/data-lake (fetched 2026-08-29T10:56:19.231130+00:00, sha a5939973d3f1)
  - site_page: https://docs.nisshi.io/docs/storage-engine-memory (fetched 2026-08-29T10:56:19.232647+00:00, sha 8b2791767509)
- Data as of 2026-08-30T08:39:29.467469+00:00.