Sometimes agents need to talk to each other. Your Chief of Staff might need to ask your Pair Programmer about a deployment timeline. How does that work? OpenClaw supports this through 2 mechanisms.
The /tools/invoke endpoint lets one agent call another agent's tool directly. The sessions_send function lets one agent send a message into another agent's session. Think of invoke as a function call and sessions_send as dropping a note on someone's desk. Use invoke for synchronous requests where you expect a response right away. Use sessions_send for async notifications where an immediate reply isn't needed.