Postboy Help

Versions

Postboy is published in two active major lines that are maintained in parallel.

Line

RxJS

Example

Notes

3.x

^7

3.5.3

Current line: staged middleware, message-driven bus mutations

1.x

^6

1.4.2

Legacy line for RxJS 6 projects

How versioning works

  • Major — the RxJS generation (1 for ^6, 3 for ^7). When a new RxJS major appears, a corresponding Postboy line follows.

  • Minor — feature and documentation releases are synchronized across lines: a feature that lands in 1.4 also lands in 3.4 with the same changes.

  • Patch — bug fixes and internal improvements may diverge between lines.

Pick the major that matches your project's RxJS version; within it, only the latest minor receives active support.

Release notes

Notes are organized by minor cycle, with the patches included in each:

Upgrading 3.4 → 3.5

The 3.5 line removes the bus-mutation methods from PostboyService and redesigns middleware. Most application code keeps working untouched; the two places to review are custom middleware and any use of lock/unlock/addMiddleware/addNamespace-style calls:

@artstesh/postboy-testing (3.4.x) works against both postboy 3.4.x and 3.5.x.

07 September 2026