Crate kojin 

kojin

Async distributed task queue for Rust — the equivalent of Celery (Python), BullMQ (Node.js), Sidekiq (Ruby), and Machinery (Go).

This is the main facade crate. It re-exports types from kojin_core, the #[task] proc-macro from kojin_macros, and optionally the Redis broker from kojin_redis.

Features

• Async-first worker runtime built on Tokio
• #[kojin::task] proc-macro for defining tasks
• Pluggable broker trait (Redis included)
• Composable middleware (tracing, metrics)
• Workflow orchestration: chain, group, chord
• Result backends (memory, Redis, PostgreSQL)
• Graceful shutdown, weighted queues, configurable retries

Quick Start

use kojin::{KojinBuilder, MemoryBroker};

let broker = MemoryBroker::new();
let worker = KojinBuilder::new(broker)
    .concurrency(4)
    .queues(vec!["default".into()])
    .build();
worker.run().await;

Modules

backoff

broker

canvas

codec

context

error

memory_broker

memory_result_backend

message

middleware

queue_weight

registry

result_backend

shutdown

signature

state

task

task_id

worker

Macros

chain

Create a chain of tasks.

group

Create a group of tasks.

Structs

JsonCodec

JSON codec using serde_json.

KojinBuilder

Builder for configuring and running a Kojin worker.

MemoryBroker

In-memory broker for testing and development.

MemoryResultBackend

In-memory result backend for development and testing.

MetricsMiddleware

Simple metrics middleware that tracks task counts.

RedisBroker

Redis-backed message broker.

RedisConfig

Redis broker configuration.

RedisResultBackend

Redis-backed result storage.

Signature

A type-erased task invocation descriptor.

TaskContext

Task execution context providing type-safe access to shared data.

TaskId

Unique task identifier backed by UUID v7 (time-ordered).

TaskMessage

A task message that flows through the broker.

TaskRegistry

Registry mapping task names to type-erased handlers.

TracingMiddleware

Middleware that emits tracing spans for task execution.

WeightedQueue

A queue with an associated weight.

Worker

The worker loop that dequeues and executes tasks.

WorkerConfig

Worker configuration.

WorkflowHandle

Handle returned after submitting a workflow.

Enums

BackoffStrategy

Strategy for calculating retry backoff delays.

Canvas

A composable workflow description.

KojinError

Core error type for Kojin.

QueueWeight

Queue priority weight for weighted queue selection.

TaskState

Lifecycle state of a task.

Traits

Broker

Message broker responsible for enqueuing and dequeuing task messages.

Codec

Serialization codec for task payloads.

Middleware

Middleware hook for task execution pipeline.

ResultBackend

Backend for storing and retrieving task results.

Task

A unit of work that can be enqueued and executed by a worker.

Functions

chord

Create a chord: a group with a callback that fires when all members complete.

Type Aliases

TaskResult

Convenience result alias.

Attribute Macros

task

Derive a task struct and Task impl from an async function.