Is Relay(circuit) transparent to application?

[spgyip]

I have read the Relay specs, also test codes as relay_test.go.

It seems that using the Relay way is not transparent to my codes?

Which means I have to write codes:

1. Try using a direct way
2. If 1) fail, try using relay way

Like:

s, err := host.NewStream(context.Background(), peerID, "/echo/1.0.0")
if err!=nil {
    r := NewRelay(context.Background(), host)
    r.DialPeer(rctx, rinfo, dinfo)
    ....
}

If this is true, I think this is a little complex to application codes, or something I have mis-understand?

[vyzo]

Relay, once configured in libp2p, is transparent in the sense that it automatically connects to relay addresses.

[whyrusleeping]

@anticpp the relay is transparent. It is embedded inside the host as a transport, so if you try to dial a relay address, you will automatically use the relay.

However, it is not yet automatic. You need to explicitly specify a relay address for the peer you wish to relay a connection to

[Stebalien]

AutoRelay has been created (although it doesn't always work all that well at the moment). #1039 replaces this.