WarpStream Kafka client API Documentation

Package: @alt-stack/kafka-client-warpstream

This is a generated-schema Kafka producer with fixed WarpStream-oriented KafkaJS defaults. It is distinct from @alt-stack/workers-warpstream: this package publishes domain events to topics; the Workers package routes named job executions.

createWarpStreamClient

async function createWarpStreamClient<T extends TopicsMap>(
  options: WarpStreamClientOptions<T>,
): Promise<KafkaClient<T, Producer>>

import { createWarpStreamClient } from "@alt-stack/kafka-client-warpstream";
import { Topics } from "./generated-events.js";

const client = await createWarpStreamClient({
  bootstrapServer: "localhost:9092",
  clientId: "accounts-publisher",
  topics: Topics,
});

await client.send("user-events", { userId: "u_123", kind: "created" });
await client.disconnect();

WarpStreamClientOptions<T>

Property	Type	Required	Behavior
bootstrapServer	string	yes	the only broker placed in the KafkaJS brokers array
topics	T extends TopicsMap	yes	topic schemas for inference and runtime validation
clientId	string	no	defaults to "warpstream-client"
producerConfig	Partial<ProducerConfig>	no	spread over the adapter defaults
onError	(error: Error) => void	no	called before connection, validation, or send errors are thrown

The KafkaJS connection timeout is fixed at 10,000 ms. Producer defaults are metadataMaxAge: 60_000 and allowAutoTopicCreation: false; explicit producerConfig values override those producer defaults. Every send explicitly uses KafkaJS LZ4 compression.

The options do not currently expose KafkaJS ssl, sasl, a custom socket factory, or a prebuilt Kafka instance. If the endpoint requires those settings, use the KafkaJS client and provide a fully configured KafkaJS instance.

Send and error behavior

send and sendBatch validate through the supplied Zod schema, JSON-stringify records, and apply SendOptions. They throw ValidationError, SendError, or ConnectionError from @alt-stack/kafka-client-core. producer exposes the connected KafkaJS Producer; disconnect() delegates to it.

Re-exports

The package re-exports KafkaClient, TopicsMap, SendOptions, KafkaClientError, ValidationError, SendError, and ConnectionError. See Kafka client core for exact properties.