Broker Mode

Broker Mode

Broker mode accepts multiple clients and forwards received bytes to the other connected clients. It is useful for manual collaboration, local labs, CTFs, debugging, and simple multi-peer terminal chat.

It is not a C2 component. It does not provide persistence, stealth, autonomous operation, embedded scripting, or tasking behavior.

Basic Broker

Start a broker:

wcat broker 0.0.0.0 5555

Connect clients:

wcat connect 127.0.0.1 5555

Chat Mode

--chat prefixes relayed messages with client labels and escapes terminal control bytes.

wcat broker --chat 0.0.0.0 5555

Client Limits

Limit connected clients:

wcat broker --chat --max-clients 16 0.0.0.0 5555

Set the per-client output buffer:

wcat broker --chat --broker-buffer 131072 0.0.0.0 5555

Slow clients are dropped when their output buffer cannot keep up. This keeps one slow receiver from blocking the whole broker.

Unix Socket Broker

Use a Unix domain socket for local-only broker workflows:

wcat broker --unix --chat /tmp/wcat-chat.sock
wcat connect --unix /tmp/wcat-chat.sock

Access Control

Restrict TCP broker peers with CIDR or exact IP rules:

wcat broker --allow 192.0.2.0/24 0.0.0.0 5555
wcat broker --deny 198.51.100.10 0.0.0.0 5555

Deny rules are evaluated before allow rules.