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Copyright 2025-2026, Matthias Reik <fledex@reik.org>
Modified version of : https://github.com/SchedEx/SchedEx
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# Fledex Scheduler
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[](https://hex.pm/packages/fledex_scheduler)
[](https://hexdocs.pm/fledex_scheduler)
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[](https://www.bestpractices.dev/projects/10474)
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> #### [!IMPORTANT] {: .warning}
>
> This repository is based on [SchedEx](https://github.com/SchedEx/SchedEx), but got
> heavily modified to fit the needs of [Fledex](https://github.com/a-maze-d/fledex). I tried
> to keep the interface still the same, so you should be able to use it as a drop-in
> replacement as well.
>
> If you don't see a need for the additional features (like defining jobs) you probably want
> to use SchedEx instead. This `README.md` only describes the parts that differ from `SchedEx`.
> For the other parts, look at the [`SchedEx` library documentation](https://hexdocs.pm/sched_ex/readme.html).
>
> Not everything has been adjusted to the new home and therefore you will still find a lot
> of references to SchedEx (that might, or might not be accurate).
`Fledex_Scheduler` is a "simple yet deceptively powerful scheduling library for Elixir. Though it is almost trivially simple by design, it enables a number of very powerful use cases to be accomplished with very little effort".
Fledex_Scheduler is a fork of SchedEx that is written by [Mat Trudel](http://github.com/mtrudel), and development is generously supported by the fine folks
at [FunnelCloud](http://funnelcloud.io). It has been adapted to easily integrate into [Fledex](https://github.com/a-maze-d/fledex)
For usage details, please refer to the [documentation](https://hexdocs.pm/fledex_scheduler) and look at the original [`SchedEx` library documentation](https://hexdocs.pm/sched_ex/readme.html).
## Basic Usage
`Fledex.Scheduler.run_job/2` is the function most commonly used. You first define a `Fledex.Scheduler.Job` before you schedule the job. Thus, your code will look something like the following:
```elixir
alias Fledex.Scheduler
alias Fledex.Scheduler.Job
job =
Job.new()
|> Job.set_name(:test_job)
|> Job.set_schedule(crontab)
|> Job.set_task(fn ->
# do something useful
:ok
end)
|> Job.set_repeat(true)
|> Job.set_run_once(false)
|> Job.set_timezone("Etc/UTC")
|> Job.set_overlap(false)
|> Job.set_nonexistent_time_strategy(:adjust)
|> Job.set_context(%{strip_name: :test_strip, job: :test_job})
{:ok, pid} = Scheduler.run_job(job)
```
If more control over the scheduling process is required (for example by integrating it into a supervision tree) it's also possible to use the Runner (`Fledex.Scheduler.Runner`) directly.
The `Fledex.Scheduler.run_job/2` maps directly to the `Fledex.Scheduler.Runner.run/3` or `Fledex.Scheduler.Runner.start_link/3` with additional server options.
## Differences vs SchedEx
`SchedEx` was the base for this library and the core implementation hasn't changed. A [`Job`](`Fledex.Scheduler.Job`)
definition has been added. This `Job` is not only used in the [`run_job`](`Fledex.Scheduler.run_job/2`) but also under the hood in all the other interface functions, i.e. [`run_every`](`Fledex.Scheduler.run_every/3`), [`run_at`](`Fledex.Scheduler.run_at/3`), and [`run_in`](`Fledex.Scheduler.run_in/3`). An attempt was
made to keep the same semantics in the interface so it can act as a drop-in replacement for SchedEx. Still, no guarantee can be given that this is true in all cases.
The scheduling can happen in various forms:
* delay based (in milliseconds)
* delay based with a unit (as a tuple [`{unit, amount}`](c:Fledex.Scheduler.Job.unit/0))
* crontab based, either as a `Crontab.CronExpression` or as a string (that will be parsed)
In addition a clearer definition was introduced between the different type of options (`job_opts`, `test_opts`, and `server_opts`), 100% test, `@spec` and `@doc` coverage has been added, and
a lot of automatisms in the CI pipeline.
## Copyright and License
Copyright (c) 2025-2026, Matthias Reik <fledex@reik.org>
Copyright (c) 2018 Mat Trudel on behalf of FunnelCloud Inc.
This work is free. You can redistribute it and/or modify it under the
terms of the MIT License. See the [LICENSE.md](./LICENSE.md) file for more details.
