Avahi browsing example in Vala

After recently posting an example of publishing services in Vala using Avahi, let’s try to paint the whole picture by posting an example of  browsing those services. Enjoy !

using Avahi;
public class AvahiBrowser {
    private const string service_type = "_demo._tcp";

    private Client client;
    private MainLoop main_loop;
    private List<ServiceResolver> resolvers;
    private ServiceBrowser service_browser;

    public AvahiBrowser () {
    main_loop  = new MainLoop ();
    try {
        service_browser = new ServiceBrowser (service_type);
        service_browser.new_service.connect (on_new_service);
        service_browser.removed_service.connect (on_removed_service);
        client = new Client ();
        client.start ();
        service_browser.attach (client);
        resolvers = new List<ServiceResolver> ();
        main_loop. run ();
     } catch (Avahi.Error e) {
     warning (e.message);

public void on_found (Interface @interface, Protocol protocol, string name, string type, string domain, string hostname, Address? address, uint16 port, StringList? txt) {
    print ("Found name %s, type %s, port %u address%s\n", name, type, port, address.to_string ());
public void on_new_service (Interface @interface, Protocol protocol, string name, string type, string domain, LookupResultFlags flags) {
    ServiceResolver service_resolver = new ServiceResolver (Interface.UNSPEC,
                                                            service_resolver.found.connect (on_found);
    service_resolver.failure.connect ( (error) => {
        warning (error.message);

    try {
        service_resolver.attach (client);
    } catch (Avahi.Error e) {
        warning (e.message);

    resolvers.append (service_resolver);

public void on_removed_service (Interface @interface, Protocol protocol, string name, string type, string domain, LookupResultFlags flags) {
    print ("Removed service %s, type %s domain %s\n", name, type, domain);

static int main (string[] args) {
    AvahiBrowser browser = new AvahiBrowser ();

    return 0;

For any questions or for any suggestions on improving this example, feel free to contact me at viorel.visarion@gmail.com.

4 thoughts on “Avahi browsing example in Vala

    1. Nice example, looks a lot more straightforward than using Avahi.
      It would be a better option, but I am doing both service publishing and service service resolving in my project and it would be best to do both in the same manner.


  1. This is great, device discovery has really improved in the last couple years and really makes life easier.


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