Struct Presence 

pub struct Presence {
    pub mode: Option<String>,
    pub relay: Option<String>,
    pub relays: Vec<String>,
    pub rendezvous: Option<String>,
    pub max_occupants: Option<u32>,
    pub voice: bool,
    pub owner_required: bool,
    pub extra: Extra,
}

Presence policy — the (optional) upgrade from a solo world to a shared one.

Presence on the Thread is federated: a world names its own relay(s), so there is no global chokepoint. Prefer relays — an ordered list of interchangeable, conformant relays (primary first, then fallbacks) — so no single relay URL is a point of failure. The singular relay is retained for backward compatibility; relay_list returns the effective, de-duplicated order to try.

Fields

mode: Option<String>

Presence tier: "solo", "p2p", or "relay" (see presence-topology-v0.1). Absent → inferred from whether any relay is named. Forward-looking; a browser that only implements the relay tier treats "p2p" as a hint it may ignore.

Declaration, not fact. The address fields decide what a browser can actually do; mode states what the author meant, and MUST agree. When they disagree the addresses win — see Presence::effective_mode.

relay: Option<String>

A single presence relay (legacy / old-browser compatibility). Absent → solo.

relays: Vec<String>

Interchangeable relays to try in order (primary first, then fallbacks). Any conformant relay works; if one is unreachable the browser tries the next.

rendezvous: Option<String>

Tier-1 P2P rendezvous URL (wss://…/rtc/<key>), meaningful with mode: "p2p". A different protocol from a relay (mesh Signal introduction, never poses), so it is a distinct field — relays keeps its ordered-failover meaning unconditionally and MAY be present alongside as the Tier-2 fallback when the mesh can’t form (the hybrid story).

max_occupants: Option<u32>

Omitted when unset — null here reads as “someone thought about the cap and chose nothing”, which is not what it means.

voice: bool

Always emitted: false is a decision about this room, not a gap.

owner_required: bool

The room lives only while its owner is present (a traveler’s home with guests over). When such a room closes, browsers SHOULD walk guests back to their own home rather than leave them in a dead copy of the world.

extra: Extra

Unknown fields, preserved across a round trip (see Extra).

Implementations

impl Presence

pub fn effective_mode(&self) -> &'static str

What this world can actually do, as opposed to what it says.

mode is a declaration; the address fields are the facts, and a declaration that contradicts them is not a second source of truth. A world claiming mode: "relay" with no relay named cannot host anyone, and one naming a relay is not solo however it is labelled. An empty relays: [] is the absence of a relay, never a considered choice of none — a consumer deciding whether to supply one should read this rather than test for a key, because which keys are present is an emitter’s business and this is not.

pub fn mode_disagrees(&self) -> bool

Whether mode claims something the addresses don’t support — advisory, for linters and conformance rather than for the render path.

pub fn relay_list(&self) -> Vec<String>

The effective, ordered, de-duplicated list of relays to try: relays first, then the legacy singular relay if it isn’t already present. Empty → solo.

Trait Implementations

impl Clone for Presence

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Presence

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Presence

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Presence

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Presence

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.