start-core/execution-model

Enforce isomorphic execution boundaries in TanStack Start projects.

Updated Apr 1, 2026

Search Tags:#security #frontend-backend #environment-variables #server-client #tanstack-start #isomorphic #execution-model

Ready to run

npx skills add https://github.com/cill-i-am/task-tracker --skill start-core-execution-model-cill-i-am

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: start-core/execution-model
Source: https://github.com/cill-i-am/task-tracker/tree/main/.agents/skills/tanstack-start-execution-model
Command: npx skills add https://github.com/cill-i-am/task-tracker --skill start-core-execution-model-cill-i-am

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Isomorphic-by-default principle, environment boundary functions (createServerFn, createServerOnlyFn, createClientOnlyFn, createIsomorphicFn), ClientOnly component, useHydrated hook, import protection, dead code elimination, environment variable safety (VITE_ prefix, process.env).

Core Features & Use Cases

Isomorphic by default: code runs in both server and client unless you opt into a specific boundary.
Boundary primitives: createServerFn, createServerOnlyFn, createClientOnlyFn, createIsomorphicFn to control execution, plus ClientOnly and useHydrated for UI and hydration behavior.
Environment variable safety: enforce VITE_ prefix usage on client and require server-only access for secrets.

Quick Start

Install and start using createServerFn and createClientOnlyFn in your TanStack Start project to enforce safe, isomorphic execution across your app.

Frequently Asked Questions about start-core/execution-model

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I prevent server secrets from leaking in TanStack Start isomorphic code?▼

Prevent server secret leaks in TanStack Start isomorphic code by enforcing execution boundaries using createServerOnlyFn and createServerFn to strictly isolate server-side logic and environment variable access from client bundles.

What's the best way to share isomorphic logic between server and client in TanStack Start?▼

The best way to share isomorphic logic is using createIsomorphicFn, which allows you to define unified interfaces that execute differently on the server and client while safely maintaining the isomorphic execution boundary.

How do I safely use environment variables in TanStack Start client-side code?▼

Safely use environment variables in TanStack Start client-side code by enforcing the VITE_ prefix for public variables, while requiring strict server-only access for secrets to prevent accidental leakage into client bundles.

When do I need to use ClientOnly and useHydrated in an isomorphic application?▼

Use ClientOnly and useHydrated in isomorphic applications when rendering UI components that must only execute or display after client-side hydration, preventing server execution mismatches and protecting client-only utility boundaries.

Does TanStack Start support createServerFn for RPC-style server functions?▼

Yes, TanStack Start supports createServerFn for RPC-style server functions, enabling strict server-side execution boundaries to safely handle data fetching and mutations without exposing server secrets to the client.