Compiling CAF requires CMake and a C++11-compatible compiler. To get and compile the sources on UNIX-like systems, type the following in a terminal:

We recommended to run the unit tests as well:

If the output indicates an error, please submit a bug report that includes (a) your compiler version, (b) your OS, and (c) the content of the file build/Testing/Temporary/LastTest.log.


  • Lightweight, fast and efficient actor implementations
  • Network transparent messaging
  • Error handling based on Erlang’s failure model
  • Pattern matching for messages as internal DSL to ease development
  • Thread-mapped actors for soft migration of existing applications
  • Publish/subscribe group communication

Minimal Compiler Versions

  • GCC 4.8
  • Clang 3.4
  • Visual Studio 2015, Update 3

Supported Operating Systems

  • Linux
  • Mac OS X
  • Windows (static library only)

Hello World Example

#include <string>
#include <iostream>

#include "caf/all.hpp"

using std::endl;
using std::string;

using namespace caf;

behavior mirror(event_based_actor* self) {
  // return the (initial) actor behavior
  return {
    // a handler for messages containing a single string
    // that replies with a string
    [=](const string& what) -> string {
      // prints "Hello World!" via aout (thread-safe cout wrapper)
      aout(self) << what << endl;
      // reply "!dlroW olleH"
      return string(what.rbegin(), what.rend());

void hello_world(event_based_actor* self, const actor& buddy) {
  // send "Hello World!" to our buddy ...
  self->request(buddy, std::chrono::seconds(10), "Hello World!").then(
    // ... wait up to 10s for a response ...
    [=](const string& what) {
      // ... and print it
      aout(self) << what << endl;

void caf_main(actor_system& system) {
  // create a new actor that calls 'mirror()'
  auto mirror_actor = system.spawn(mirror);
  // create another actor that calls 'hello_world(mirror_actor)';
  system.spawn(hello_world, mirror_actor);
  // system will wait until both actors are destroyed before leaving main

// creates a main function for us that calls our caf_main