ag2-network-discussion

AG2 Network — Discussion Adapter

discussion is an N-party round-robin channel. Participants speak in a fixed order, cycling indefinitely until you close it. The adapter enforces "wait your turn" via validate_send; the hub's can_send probe lets each agent's default handler skip wasted LLM calls when it isn't that agent's turn.

Prerequisite: read ag2-network-quickstart first. This skill assumes you already know Hub.open, HubClient.register, the channel lifecycle, and Envelope basics.

When to use

• "Three agents debating in turn"
• "A panel discussion / brainstorm with a fixed cast"
• "Round-robin reviewers commenting on a draft"
• Any fixed-order N-party turn-taking where each participant gets a slot per cycle

Don't use discussion for:

• Conditional handoffs ("if alice mentions security, hand to the security expert") → use ag2-network-workflow.
• Pipelines where each step happens once → use ag2-network-workflow with TransitionGraph.sequence([...]).
• Two participants with no fixed order → use conversation (covered in ag2-network-quickstart).
• Strict 1Q1R → use consulting (covered in ag2-network-quickstart).

Shape

Participants	2+
Turn order	Round-robin (creator first, then participants in registration order)
Auto-close	No
Termination	Explicit channel.close() or TTL (see "Closing" below)
Default view	NamedWindowedSummary(recent_n=N*2) where N is the participant count
Default expectations	turn_within(120s, warn), turn_within(600s, hide)
Knob	{"ordering": ORDERING_ROUND_ROBIN} (only ordering shipped today)

The view recent-window is sized to N*2 so each agent's projection covers roughly the last two full cycles — enough context for a coherent reply without ballooning the prompt as the discussion grows.

Discussion agents, the NetworkPlugin, and turn-taking

HubClient.register(...) attaches NetworkPlugin by default — that adds peers / channels / tasks / context / delegate, the identity-level verbs. DiscussionAdapter.tools_for(...) returns []: the discussion adapter offers no channel-specific tools (no say). A participant contributes its turn purely by returning a reply — the default handler posts the round-end EV_TEXT(reply.body) as that turn's contribution.