What is chumak?

`chumak` is a library written in [Erlang]( It implements the ZeroMQ Message Transport Protocol (ZMTP). `chumak` supports ZMTP version [3.1](


The goal of `chumak` application is to provide up-to-date native Erlang implementation of ZMTP.

1. Resource Property *(NEW in 3.1!)*
2. Request-Reply pattern
3. Publish-Subscribe pattern
4. Pipeline Pattern	
5. Exclusive Pair Pattern
6. Version Negotiation
7. NULL Security Mechanism
8. Error Handling
9. Framing
10. Socket-Type Property & Identity Property
11. Backwards Interoperability with ZMTP 3.0


You can install `chumak` from []( by including the following in your `rebar.config`:

	{chumak, "X.Y.Z"}
where _X.Y.Z_ is one of the [release versions](

For more info on rebar3 dependencies see the [rebar3 docs](


See [examples](examples). Otherwise use just like a regular Erlang/OTP application.

If you would like to use [python tests](python-test) to try language interop, you need to have [pyzmq]( installed. 

$ rebar3 compile

$ rebar3 eunit -c
The `-c` will allow you to see the test coverage by running the command below.

$ rebar3 cover

Generate Docs
$ rebar3 edoc

[Architecture](docs/ describes the system structure.


See  [Contributing](

1. Why another Erlang implementation?

   Because the existing Erlang implementations and bindings are out of date.

2. Can I use `chumak` for free?

   Yes, as long as you abide by the terms of the [MPLv2 license](LICENSE). In short, you can include this code as a part of a larger work, even commercial. It is only when you modify `chumak` source code itself that you have to make that change available. Please read the license, as this description is not complete by any means.

3. Do I have to sign over my copyright when contributing?

   No. Everyone owns the piece of code they contribute.
   Please see [Contributing]( for details.

Future work
1. CurveZMQ - add security, with which chumak is compatible.

This project is licensed under Mozilla Public License Version 2.0.
See [license](LICENSE) for complete license terms.

From [Wikipedia](

>Chumak (Ukrainian: чумак) is a historic occupation on the territory of the modern Ukraine 
>as merchants or traders, primarily known for the trade in salt.