Matchmaking

Players join with a rating; the window of ratings they accept widens the longer they wait; a match is proposed when enough players fall in each other's windows, and every one of them must accept in time. When all do, the queue reserves a session for them and tells each its key. A party queues as one block: its leader joins with party (the other members), each member confirms by joining with leader, and the block is matched whole or not at all.

Starter: crate matchmaker, node type matchmaker, keyed by the queue name (ranked, casual, ...). Module: kit.matchmaking.queue(name) in CrowdyJS, matchmaking().queue(name) in CrowdyCPP, kit.matchmaking.queue(name) in CrowdyPy.

Endpoints

Endpoint	Who	What
join { rating, party?, leader? }	players	Joins, leads a party, or confirms one; answers the player's place. conflict (a match to accept), limit (party size), forbidden, full
leave, decline	players	Leaves the queue, a forming party or a proposal
accept	players	Accepts a proposal; matched with the session key once everyone has
status	players	The player's own place: idle, party, queued, proposed or matched
configure { .. }	developers	players_per_match, the windows, the accept and party times

Every change takes an action_id, answered once; refusals carry the codes above (see the protocol).

Topics

queue: snapshots of how many are waiting, proposed and forming, never who. A waiting client asks status (the module's watch does it on a timer).

Config

A type's seed (seed_b64 in the manifest, the same for every key) is the starter's JSON config; what it leaves out keeps its default. players_per_match, window and widen_per_sec up to max_window, accept_ms, party_ms.

CrowdyJS

const queue = kit.matchmaking.queue('ranked');
queue.onMatched(async (key) => {
  const session = kit.sessions.open(key);
  await session.watch();
  await session.join();
});
await queue.join({ rating: 1200 });
queue.watch(); // asks for the player's place while they wait

CrowdyCPP

auto& queue = kit->matchmaking().queue("ranked");
queue.onMatched([&](const std::string& key) { kit->sessions().open(key).watch(); });
queue.join({.rating = 1200}, [](crowdy::kit::KitReply r) {
  if (!r.ok()) log(r.code().empty() ? r.message() : r.code());
});
queue.watch();
game.poll(); // replies, topic messages and mirror changes arrive here

CrowdyPy

queue = kit.matchmaking.queue("ranked")
queue.on_matched(lambda key: asyncio.create_task(play(key)))
await queue.join(1200)
watching = asyncio.create_task(queue.watch())