Client command
In one line: a typed intent a client sends — "move there", "attack that" — delivered to systems in the next tick, per session and in order, and always answered.
A command type is an unmanaged struct, declared once with its policy: a rate and burst per session, the roles allowed to send
it, whether it coalesces (only the newest per session per tick survives — a move target) or queues, and an optional stateless
pre-check. Its fields travel under codecs like any replicated field; a contracts assembly that references only Typhon.Protocol can
declare them with attributes ([ReplicatedMessage], [Quant], [EntityRef]), so .NET clients share the exact struct.
Two gates, two jobs. On the transport thread, before a tick sees it, a command is checked against the wire, the session's inbound
byte budget, its type's rate, the session's role and the pre-check. What passes is drained into typed buffers at the start of the next
tick and read by systems with ctx.Subscriptions.Commands<T>(). Semantic validation — is the target in range, is the cooldown over,
does the player own that item — is the system's, because the state it must agree with is the system's.
Entities are named by netId, the identity the client was sent. TryResolve(session, netId, out entity) answers only for entities
that session actually holds — in its view as last sent, or the one it controls — so a client cannot target what it was never shown.
Every refused command is answered. A refusal travels back in the session's next frame as an ACK with a reason — rate-limited,
forbidden by role, rejected by the pre-check or by the application (Reject) — while SELF.lastSeq reports the last command the tick
drained, so a predicting client settles every command it sent. A client that keeps sending what is refused is closed with 1008.
How it relates
- Replication session — the session's role decides which commands it may send.
- System — commands are read in the tick, by ordinary systems.
- Replication event — the other direction: the server telling clients something happened.
In the API
SubscriptionsRegistry.Command<T>(…)andCommandBuilder<T>—Rate,Roles,Coalesce,Precheck,Field,Ignore.SubscriptionsCommands—Commands<T>(),TryGetLatest,TryResolve,Reject.ReplicatedMessageAttribute,AckReasons.
Learn & use
- Narrative: Guide ch.7 §5 — commands
- Feature detail: Commands & acknowledgements