package zmq

6.0.0: 2026-09-27

• Fix Eio multipart sending: send_all and send_msg_all now pass their messages correctly and use the sender queue. Add multipart send/receive coverage (#132, @ComanderP).

• Handle EINTR without leaving sockets in an inconsistent multipart state:

  • ZMQ operations automatically retry on EINTR, except context termination, polling, and proxying, which remain interruptible.
  • Async and Lwt multipart operations can resume after EAGAIN, and their event loop handles EAGAIN while reading socket events.
  • Add EINTR regression tests for the core, Async, Lwt, and Eio packages. Thanks to @rand00 for reporting and working on the multipart problems.
• Allow other OCaml threads to run while Context.terminate waits for all sockets to close.
• Keep the Async bindings compatible with Async v0.15 while suppressing the deprecation warning for Async_kernel.Ivar.fill.

5.3.0

• Add eio binding in zmq-eio (#126, @andersfugmann)

5.2.2

• Fix race in monitor test (#129, @andersfugmann)

5.2.1

• Forward compatibility with Lwt 6.0 (#122, @andersfugmann)
• Fix wrong fd type for zmq-async, effecting s390x (#123, @andersfugmann)

5.2.0

• Remove dependency on StdInt (#121, @andersfugmann)
• Silence warnings about const char* when writing to the inside of an allocated string value (#116, @Leonidas-from-XIV)

5.1.5

• fix bug in STREAM sockets (#114, @c-cube)

5.1.4

• Add poll helpers: mask_in, mask_out, mask_in_out
• Fix build with OCaml 4.13 (#108, #110, @Leonidas-from-XIV)
• Fix Xpub typo (#107, @roddyyaga)

5.1.3

• Support building with dune 1.x and 2.x (#104)
• Bring back support for OCaml 4.03 for zmq and zmq-lwt (#101, #102)

5.1.2

• Use unix sockets in tests to avoid permission problems when running in a sandbox environment.
• Make monitor test more reliable by explictly waiting for each event to arrive.

5.1.1

• Fix EINVAL when attempting to get the curve encryption keys (#85, #86, #91)
• Do not depend on configurator anymore (#96)
• Depend on v0.11 versions of Jane Street packages to not fail on makedev issue. This requires us to drop support for OCaml 4.03 (#93)

5.1.0

• Implement Msg.gets (#87, #90)
• Improve support for OCaml 4.08+ (#83, #89)
• Properly allocate right size of caml block (#88)
• Update build config to use new dune syntax
• Remove configurator in favor of dune.configurator. This removes the build time dependency on the configurator and base packages.

5.0.0

• Change build system to use jbuilder instead of oasis. This also adds proper support for pkg-config installed zmq.
• Import zmq-async and zmq-lwt. The old bindings async-zmq and lwt-zmq are now deprecated.
• Refactor zmq-async and zmq-lwt to be supported out of a single code base. This regularizes the interface, and dramatically improves and stability.
• Add support for and reading & writing bigarrays. This interfaces allows the user to reduce needless copying of packets sent by the bindings.
• Rename module ZMQ to Zmq.

4.0-8

• Add threading example by Stavros Polymenis
• Minor addition to API documentation
• Remove OCaml version requirement in opam package (strictly not part of this release, but still)

4.0-7

• Fixes compilation errors when compiling with 4.03 (and 4.04)
• Fixes a generic problem with deallocating resources though finalisers. As a result no resources are automatically released though finalisers. However a warning will be printed to stdout if resources are leaked
• Include oasis autogenerated files, removing the dependency on oasis when installing

4.0-5

• The build system now also looks for ZMQ headers and libraries in /usr/local

4.0-4

• Compatibility with ZeroMQ 4.1

4.0-3

• Fixed error when GC collecting contexts freed by ZMQ.Context.terminate
• Fixed overflow bug in get_bytes_option

3.2-2

• Remove get_identity/set_identity socket-type restrictions