sdk/lib/sys/cpp/tests/meta/echo_server.cml

{
    include: [ "syslog/client.shard.cml" ],
    program: {
        runner: "elf",
        binary: "bin/helper_proc_bin",
        args: [ "--echo" ],
    },
    capabilities: [
        { protocol: "test.placeholders.Echo" },
    ],
    expose: [
        {
            protocol: "test.placeholders.Echo",
            from: "self",
        },
    ],
}