NPCs, mobs and pets

The mobs, NPCs and pets of one area of the world, moved on a timer and shown to nearby players as server-driven actors. Mobs wander near home, chase the nearest player in range, go home past their leash, take players' hits and respawn; NPCs walk their routes and talk; pets belong to a player and follow them while summoned. The type needs the world.read scope (to see where players are) and calls world (for its topic). areaAt(chunkX, chunkZ) finds the area for where a player stands.

Starter: crate npc-mobs, node type npcs, keyed by the area's centre chunk (a shard key of 8 chunks, "x,z"). Module: kit.npcs.area(key) in CrowdyJS, npcs().area(key) in CrowdyCPP, kit.npcs.area(key) in CrowdyPy.

Endpoints

Endpoint	Who	What
state	anyone	Every member's public view
attack { mob }	players	The hub decides reach, cooldown and damage: not_in_area, out_of_reach, cooldown, down
talk { npc }	players	What the NPC says
adopt { species, name }	players	A pet where the player stands: not_in_area, limit, full
rename, summon, dismiss, release { pet }	the pet's owner	forbidden for anyone else
pets	players	The caller's pets, with their bond (private: never on the topic)

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

Topics

area: a delta per member once a second (type_name Mob, Npc or Pet, their public properties).

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. The area's spawn table, routes and pet species; see the crate.

CrowdyJS

const area = kit.npcs.areaAt(chunkX, chunkZ);
await area.watch();
try {
  await area.attack(area.mobs()[0].id);
} catch (e) {
  if (e instanceof KitError && e.code === 'cooldown') showCooldown();
}
const pet = await area.adopt('cat', 'Mog');
await area.summon(pet);

CrowdyCPP

auto& area = kit->npcs().areaAt(chunkX, chunkZ);
area.watch([&](crowdy::kit::KitReply) {
  area.attack(area.mobs().at(0).id, [](crowdy::kit::KitReply r) {
    if (r.code() == "cooldown") showCooldown();
  });
});
game.poll(); // replies, topic messages and mirror changes arrive here

CrowdyPy

area = kit.npcs.area_at(chunk_x, chunk_z)
await area.watch()
try:
    await area.attack(area.mobs()[0].id)
except KitError as e:
    if e.code == "cooldown":
        show_cooldown()