What problem does it solve? Working on SparkEngine's multiplayer stack requires knowing which networking and security components are actually wired versus test-only, what the wire protocol guarantees, and where the known gaps are. This Skill provides a verified runbook of the UDP transport, packet validation, client prediction, lag compensation, and MMO account security so changes are made against real code behavior rather than assumptions. ## Core Features & Use Cases - Wire protocol and ingress rules: Documents the SPRK magic header, channel limits, payload caps, PacketValidator schema enforcement, and the absence of protocol version negotiation. - Auth and credential security ledger: Reconciles exact claims about PBKDF2-HMAC-SHA256 at 600k iterations, OS-backed CSPRNG usage, 128-bit session tokens, and fail-closed login behavior in MMOAccountSystem. - Open gaps and decision rules: Lists unwired encryption, stub SteamTransport, fallback singleton, and skip-trap test caveats, plus rules for adding message types, hashing passwords, and generating tokens. - Use Case: When asked to add a new network message type, follow the decision rule to add the MessageType enum, register a MessageSchema in PacketValidator, update the wire-format spec, and add an adversarial test case. ## Quick Start Ask the assistant to verify whether the login system is secure and to walk through the session token and password hashing implementation using this Skill.
