Support Policy

The supported runtime and peer lines, mirroring the project's constitution and the package's published peer ranges.

Supported Lines

Item	Supported
Node.js	>=22 (>=22.12 with NestJS 12 — see the note below the table)
NestJS	^11.0.0 || ^12.0.0
@confluentinc/kafka-javascript	^1.9 (pin the major; it tracks librdkafka)
TypeScript	^6
Validation	class-validator and Zod, both app-owned
Kafka brokers	tested against KRaft 3.8.1 and 4.3.1

Both ends of the NestJS range are tested, not assumed. The default lockfile keeps the suite on an 11.x in the middle of the range; the nestjs-compat CI matrix installs each end on top of it and runs the unit suite and the sample matrix. The oldest installable 11 graph we run is 11.0.0, pinned exactly, because nothing this package uses was added by a later 11.x; the other leg floats on ^12.0.0. See Quality & CI for how each leg proves it is testing the tree it claims to.

The Node.js floor depends on which end of that range you are on. NestJS 11 runs on any Node.js >=22. NestJS 12 is ESM-only; loading it from CommonJS code (this package, and every sample) goes through Node's require(esm), which is behind a flag before Node.js 22.12.0, so NestJS 12 needs Node.js >=22.12. engines stays >=22 because the 11 end does not need more; CI's NestJS 12 leg runs on a current 22.x.

The broker range is tested the same way: the real-broker integration suite runs once per end, against a single-node KRaft 3.8.1 and 4.3.1. Kafka 4 is KRaft-only and removed the old protocol API versions (KIP-896); the Confluent client negotiates versions with the broker, and the suite, including the broker-restart case and the @nestjs/microservices interop cases, passes against both. Brokers in between are not run, but nothing in this package depends on a feature one of them added or removed.

Peer Dependencies

The published package keeps "dependencies": {}. Everything the runtime needs is a peer, so applications install only the ecosystems they use:

• @confluentinc/kafka-javascript is an optional peer — it is loaded only when you open a real broker connection. Unit tests on KafkaTestModule never load it.
• class-validator and Zod are optional peers — install whichever validator your app uses, or neither.
• @nestjs/common, @nestjs/core, @nestjs/microservices, reflect-metadata, and rxjs are required peers.

This keeps the supply chain lean and the install matrix under the host application's control. See Quality and CI for how the empty runtime-dependency contract is enforced.

librdkafka Note

@confluentinc/kafka-javascript ships a native librdkafka binding. Alpine, Windows, and ARM64 each have their own install considerations. Because the client is an optional peer, you only take on that install when you actually connect to a broker — local development and the test suite run entirely on the in-memory broker.

Upgrade Contract

The Confluent client tracks librdkafka, so the package pins to a major (^1.9) and documents behavioral deltas on upgrade. Treat a Confluent major bump as a coordinated change.