@promin/topology

Stateful stream processing — keyed state, time windows, joins, distributed shuffle.

Install

bun add @promin/topology

Quick Example

import { StreamTopology, TopologyRunner } from "@promin/core";

const topology = StreamTopology.source(clickEvents)
  .filter((e) => e.type !== "bot")
  .keyBy((e) => e.userId)
  .tumbling(60_000)
  .count()
  .to(outputTopic);

await TopologyRunner.run(topology, {
  group: "click-counter",
  checkpointIntervalMs: 10_000,
});

Build a declarative processing DAG from a message source. Partition by key, apply time windows, aggregate, join streams, and sink results. State is checkpointed periodically and restored on crash or rebalance.

Features

• Keyed state — per-key stateful processing with typed state
• Time windows — tumbling, sliding, and session windows
• Stream joins — join multiple streams by key and time
• Distributed shuffle — repartition data across instances with .shuffle()
• Checkpointing — periodic state snapshots, automatic recovery
• Deduplication — exactly-once processing semantics

Documentation

Full docs and examples: packages/topology