chore(rivetkit): fix run engine config

[NathanFlurry]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[railway-app]

🚅 Deployed to the rivet-pr-4268 environment in rivet-frontend

Service	Status	Web	Updated (UTC)
website	❌ Build Failed (View Logs)	Web	Feb 23, 2026 at 6:38 pm
frontend-inspector	❌ Build Failed (View Logs)	Web	Feb 23, 2026 at 6:37 pm
frontend-cloud	❌ Build Failed (View Logs)	Web	Feb 23, 2026 at 6:36 pm
mcp-hub	✅ Success (View Logs)	Web	Feb 23, 2026 at 6:23 pm
ladle	❌ Build Failed (View Logs)	Web	Feb 23, 2026 at 6:23 pm

[NathanFlurry]

• chore(rivetkit): fix run engine config #4268 : 2 dependent PRs (#4271 , #4273 ) 👈 (View in Graphite)
• chore: multiplayer cookbook patterns #4261 : 1 other dependent PR (#4266 )
• docs: document queue with interval pattern #4265
• chore(rivetkit): migrate to sqlite instance per-actor for concurrency optimizations #4264
• docs: workflows #4256
• chore(rivetkit): update conns to be hibernatable #4260
• chore(inspector): add back database tab #4255
• chore: impl canInvoke for matchmaker #4253
• chore: multiplayer cookbook #4200 : 1 other dependent PR (#4201 )
• feat(dashboard): bring new tabs back #4249
• fix(rivetkit): fix sqlite teardown logic #4259
• main

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[claude]

PR #4268 Review: chore(rivetkit): fix run engine config

Summary

This PR contains two distinct sets of changes:

1. The actual fix (1 line): corrects an env var typo in the engine process config
2. New multiplayer-game-patterns-vercel example and updates to existing Vercel examples (~12k lines)

---

Core Fix

rivetkit-typescript/packages/rivetkit/src/engine-process/mod.ts

-RIVET__RUNTIME__WORKER__SHUTDOWN_DURATION: "1",
+RIVET__RUNTIME__WORKER_SHUTDOWN_DURATION: "1",

The double underscore separator (WORKER__SHUTDOWN) was incorrect — the correct env var uses a single underscore (WORKER_SHUTDOWN). This is the right fix.

---

Issues Found

Pre-built JS bundle committed to source control

examples/multiplayer-game-patterns-vercel/public/assets/index-9bY3DXxE.js and public/index.html are committed as build artifacts. The hashed filename index-9bY3DXxE.js indicates this is the output of vite build, not source. Build artifacts shouldn't live in the repo for several reasons:

• They'll become stale whenever source changes without a rebuild
• public/index.html has a hardcoded reference to the hashed asset filename: src="/assets/index-9bY3DXxE.js"
• The bundle contains minified React, the full RivetKit client library, game logic, etc. — likely >500KB of generated content

If these are needed for Vercel deployment without a build step, that should be explicitly documented. Otherwise, add public/assets/ to .gitignore and let Vercel run vite build.

Wrong domain in README deploy button

examples/multiplayer-game-patterns-vercel/README.md line 4 uses rivet-gg/rivet in the Vercel deploy URL, which should be rivet-dev/rivet per project conventions:

-https://github.com/rivet-gg/rivet/tree/main/examples/multiplayer-game-patterns-vercel
+https://github.com/rivet-dev/rivet/tree/main/examples/multiplayer-game-patterns-vercel

Wrong directory in README "Getting Started"

-cd rivet/examples/multiplayer-game-patterns
+cd rivet/examples/multiplayer-game-patterns-vercel

The README is for the -vercel variant but the cd command points to the non-vercel example. The README also says only "io-style (open lobby, 10 tps)" is covered, but the full example implements 10 game patterns.

as never type assertion in App.tsx

frontend/App.tsx:199:

matchInfo: route.matchInfo as never,

This is a type escape hatch that hides a structural type mismatch. Consider using a typed discriminated union for each game pattern's matchInfo, or casting to unknown first if you want an explicit cast ladder: as unknown as SpecificType. Using as never silently disables type-checking on this prop.

Indentation inconsistency in ranked/match.ts

The createState property in rankedMatch is double-indented compared to sibling properties (onConnect, onDisconnect, etc.):

export const rankedMatch = actor({
    events: { ... },
        createState: (   // <-- extra indent level
            _c,
            input: ...,
        ): State => {
    onConnect: (c, conn) => {  // <-- back to normal indent

---

Minor Observations

• The README description is incomplete — it only mentions "io-style" but the example covers arena, battle-royale, ranked, open-world, idle, turn-based, party, physics-2d, and physics-3d.
• The vercel.json rewrite "source": "/api/(.*)" → "destination": "/api" looks correct for the serverless function routing.
• The queue-based matchmaker patterns (io-style, arena, ranked) are well-structured and the two-phase lobby flow is clearly documented with block comments.
• The ensureColumn migration helper pattern used in the IO-style matchmaker is a nice defensive approach for schema evolution.