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Cue Documentation

Cue is a distributed, in-memory job queue with Raft-based consistency, automatic retries, and dead letter handling.

It is designed for teams that need reliable job dispatch without operating complex infrastructure like Kafka.

Core Components

  • Cue — The distributed cluster (3/5/7 nodes)
  • CueProxy — Stateless HTTP & WebSocket gateway

Architecture

Cue Cluster Architecture with Multiple Proxies

What Cue Guarantees

  • No job loss (Raft WAL survives total cluster crash)
  • At-least-once delivery (duplicates possible, idempotent consumers required for exactly-once)
  • Automatic retries with exponential backoff
  • Dead letter file with rotation
  • Bounded queues with clear backpressure

What Cue Does Not Guarantee

  • Infinite queue size
  • Exactly-once without client idempotency

The Honest Promise

Cue is simple to operate, bounded by design, and honest about its limits. Teams that need Kafka's endless persistence should use Kafka. Teams that need Redis Pub/Sub's fire-and-forget should use Redis. Teams that need an in-memory, durable, retrying job queue with straightforward operations should use Cue.