go-quartz

Go-quartz is a lightweight in-process job scheduler. Basically, it's cron but embedded directly in your Go app, no external dependencies needed.

It supports cron expressions, fixed-interval scheduling, and one-off delayed jobs. Jobs run in goroutines, so they're concurrent by default. The API is clean: create a scheduler, define a job, set a trigger, start. That's it.

It's fully free under MIT. No paid tier, no cloud version, no strings. It's a library you import and use. go-quartz is the right choice when your scheduling needs are simple and you don't need durability. Once you need jobs to survive restarts or run across multiple instances, you've outgrown it.

The catch: it's in-process only. If your app restarts, all scheduled state is lost; there's no persistence layer. For durable job scheduling where jobs survive restarts and can be distributed across multiple instances, you need something heavier. Temporal handles complex workflow orchestration. For simpler persistent job queues, look at something like River (for Postgres-backed Go jobs) or Asynq (Redis-backed).