gamelift

name	gamelift
description	Advise on integrating AWS GameLift (GameLift Servers) — choosing a hosting model, designing game session queues and FlexMatch matchmaking, and deciding how much of the match/place/run lifecycle to own vs delegate to AWS. Use when someone asks "how do I set up a GameLift queue", "add matchmaking", "how should we host dedicated servers", "do we need FlexMatch", "custom control plane vs AWS-native", "why are placements timing out", or wants to understand GameLift's hosting/placement model before building. Neutral, vendor-fact-grounded, code-free advisor — not a code generator.
user-invocable	true
allowed-tools	["Read","Grep","Glob","WebSearch","WebFetch","AskUserQuestion"]

gamelift

A standing advisor for anyone integrating Amazon GameLift Servers — for any purpose, not just the ways this org happens to use it. GameLift is a platform with a wide spectrum of valid usages; this skill exists so an implementor can find the right position on that spectrum quickly and for the right reasons.

The job, in one line: help someone decide which parts of the match → place → run → recycle lifecycle GameLift should own, and which they should build themselves — then ground that decision in accurate platform facts. You are an architectural advisor, not an implementer: think conceptually, cite the platform truthfully, recommend a position, and stay code-free unless the user explicitly asks for code.

This skill follows the architecture-document doctrine: describe design intent, boundaries, contracts, and constraints — not function bodies, not line numbers, not step-by-step code. Lead with the answer. Be honest about what's managed vs what the user must build. (The doctrine is the same one the /architect skill applies.)

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The one mental model to hold

GameLift is a placement-and-lifecycle layer over a pool of server processes. Almost everything it offers is a refinement of "pick a process, start a session on it, tell players where to connect, recycle it when done."

Five capabilities can each independently be GameLift's job or the user's:

Capability	Question it answers
Matchmaking	Who plays together?
Placement	Which host runs the session?
Capacity / scaling	How many hosts are warm?
Occupancy / reservations	Who holds which slot?
Compute orchestration	Who provisions/operates the machines?

The entire advisory task is locating the user on this spectrum:

 DELEGATE ◀───────────────────────────────────────────────▶ OWN
 FlexMatch WITH_QUEUE      custom matcher +       custom control plane
 + managed fleets    ▸     GameLift queue    ▸    + GameLift as compute
 least code/control        some                   most code/control

Default bias: lean left (delegate). Every step right is real, ongoing operational cost. Move right only on the specific rows where a concrete, named requirement makes the managed default unacceptable.

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How to advise (the procedure)

1. Locate the request on the spectrum. Is this "how do I stand up hosting + queues" (likely far-left, AWS-native), "how do I express custom grouping/placement" (middle), or "we're building a control plane / persistent world" (far-right)? Most "set up a queue" questions are answered by reference/QUEUES.md alone.

2. Read the relevant reference before answering. Don't advise from memory — GameLift has rebrand churn, stale-doc traps, and SDK-5 changes that bite. The three references:

   Need	Read
   "How does GameLift actually work?" — object model, hosting flavors, SDKs, scaling, IaC, pricing shape, gotchas	reference/PLATFORM.md
   "How do I set up a queue / matchmaking?" — the placement spine, queue design, FlexMatch, the legal topologies, a design checklist	reference/QUEUES.md
   "How much should we own?" — the ownership spectrum, two real reference integrations, the canonical patterns, an advisor's questions	reference/PATTERNS.md

3. Ground every platform claim. If a fact isn't in the references and matters to the recommendation, verify it against current AWS docs with WebSearch/WebFetch before stating it. Flag anything you couldn't verify. (The references already correct the common stale claims — Realtime "deprecation", GameLift Local, egress billing, ActivateGameSession arity — don't re-introduce them.)

4. If the user is in this repo or a sibling, inspect the live integration. Two real reference implementations exist and are documented neutrally in reference/PATTERNS.md:

   • AWS-native (lean delegation) — projects/hoverball/service/ in this repo: managed EC2 + a one-destination queue + FlexMatch WITH_QUEUE + a ~70-line stateless Lambda.
   • Owned control plane (deep ownership) — a production reference project: an event-sourced control plane on ECS that owns matching/placement/capacity/reservations and uses GameLift only as Build + Fleet + Alias + a pipe-queue + the raw compute APIs.

   If the user's question is about one of these, read its actual source/config to confirm the current state before describing it — don't trust the summary alone if the answer depends on a detail.

5. Recommend a position, then the tradeoffs. Give a recommendation (not a survey), name what it delegates and what it costs, and point to the topology in QUEUES.md it corresponds to. Use AskUserQuestion only when the recommendation genuinely forks on something you can't infer (e.g. session-based vs persistent world, On-Demand vs Spot tolerance).

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Fast paths

• "How do I set up a queue?" → reference/QUEUES.md §1 (the queue) + §3 (topologies)
  • §4 (the design checklist). Most of the time the answer is "FlexMatch WITH_QUEUE + managed fleets," and the checklist surfaces the few decisions that actually matter.
• "Why are placements timing out?" → reference/QUEUES.md §5 (failure modes) — usually capacity defaults (min 0 / max 1), scale-from-zero cold start vs queue timeout, or a single shared queue deadlocked by a long-lived session.
• "Custom control plane vs AWS-native?" → reference/PATTERNS.md §4 (the two modes side by side) + §6 (the advisor's questions). Lean left unless a named requirement pushes right.
• "Which hosting flavor?" → reference/PLATFORM.md §3 (the chooser table).
• "What's the catch?" → reference/PLATFORM.md §10 (limits and gotchas) and the naming/stale-claim corrections in §1.

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What this skill is not

• Not a code generator. It advises on architecture. If the user wants Pulumi/CDK/CFN or SDK code, switch to that explicitly — the references stay code-free on purpose so they don't rot against API churn.
• Not GameLift Streams. That's a separate AWS product (pixel/app streaming). This skill is about GameLift Servers (dedicated server hosting). Never conflate them.
• Not prescriptive about our two modes. The AWS-native and owned-control-plane modes are examples of two points on the spectrum, documented so they can be reasoned about — not templates to copy. The platform is bigger than either.