The latest v1.6.0 of SolidQueue brings a long‑awaited feature thanks to @crmne: instead of a thread pool, jobs can now run in a single fiber reactor thread. This change replaces a thread‑per‑worker model with a fiber‑based one, giving finer control over concurrency.

To enable it, set the number of fibers in your worker configuration rather than threads, for example: workers: - queues: "api*" fibers: 100 polling_interval: 0.05. The reactor runs all fibers on one thread, reducing context switches and memory overhead.

The implementation relies on the Async library, so you must add it as a dependency. Additionally, Rails must be running in fiber isolation mode (config.active_support.isolation_level = :fiber) to support the new execution path.

Fiber mode is ideal for I/O‑bound workloads, such as LLM calls, because it allows many lightweight tasks to wait on I/O without blocking other jobs. The changelog also includes transaction rollback fixes, dynamic recurring‑task updates, and first contributions from @wintan1418. Full details are in the v1.5 métachangelog.