Python client unable to dial Java host — Swarm missing _manager

[seetadev]

Hi everyone! Maciej is working on a university project where he needs to connect a Python libp2p node as a client (dialer) to a Java libp2p node (host) using a custom protocol.

• ✅ When Python is the host and Java is the client, everything works perfectly.
• ❌ But when trying the reverse—Python as client → Java host—he encounter this error:

AttributeError: 'Swarm' object has no attribute '_manager'

He has tried patching the Swarm object to add _manager, but it didn’t help. He is using the latest official py-libp2p (v0.2.7).

We should check whether this is a known issue. If we haven’t found a working solution or maintained fork that fixes the _manager bug, it would be great task to take up.

**🧩 Questions from Maciej **

1. Is there any way to get Python libp2p working as a client (dialer) with a Java libp2p host right now?
2. Or is there a fork/patch that successfully addresses this _manager bug?

Maciej's university project depends on two-way compatibility (Python ↔ Java) and he would love to avoid rewriting everything in Java.

🙏 Thank you so much for any help, pointers, or workaround suggestions!

[acul71]

Hi Maciej @mkg20001
Can you add some code and logs so that I can reproduce the error and work on it?

[mkg20001]

You've pinged the wrong one

[acul71]

Sorry about that

[paschal533]

Hi @seetadev, can you tag the right Maciej to share his code and logs like @acul71 suggested? That will be quite helpful.