Concepts

Understanding-oriented — the model behind the API and the reasons for it. Read these to build a mental model; reach for How-to when you have a task in hand.

The surface is small, but the ideas behind it — one contract for every wire pattern, a server that owns the truth, two independent seams for scaling — repay a few minutes of reading before you start wiring things together.

• Why super-line — the assembly-tax thesis, and how one typed data bus answers it.
• The contract — the two-axis model (direction × role) and the five interaction flavors it encodes.
• Server-authoritative — why the server owns rooms, topics, validation, and the role boundary.
• Transports and adapters — the two independent seams: the client↔server wire versus node↔node fan-out.
• Reconnection and delivery — what survives a drop, how resubscription works, and what await sub.ready guarantees.
• Plugins — the contract-time and runtime halves of a plugin, and how they compose into a host.
• Queues and workers — durable server-only jobs, leases, cluster-wide slots, and cron schedules.
• Comparison and FAQ — how super-line differs from Socket.IO, tRPC, and the alternatives.