The stack

Every Lodekit app is written the same way: TanStack Start with React 19 and TypeScript, styled with Tailwind CSS, importing @lodekit/sdk for services and @lodekit/ui for components. This page is what that stack is, how it gets built, and why Lodekit prescribes exactly one.

What’s in the stack

• TanStack Start — the app framework: file-based routes under src/routes/, loaders for data, server functions for writes, and server-side rendering. Apps are server-rendered: the first paint comes from the server, then React hydrates in the browser.
• TypeScript — everything is typed, end to end. The SDK’s handles, your database schema, and your route params all carry types, so your agent catches mistakes at compile time instead of at runtime.
• Tailwind CSS — utility classes for layout and spacing, on top of the shared theme’s tokens.
• @lodekit/sdk — the typed client into the service catalog: db, kv, files, tasks, events, settings, secrets, logs. It works on both sides of the contract — the browser and the server. See Data and server functions.
• @lodekit/ui — the themed component library every app imports, so all apps look like one product. See Using the UI library.

An app’s server code runs in an app worker — a per-app worker thread inside the engine that executes the app’s built server bundle. Its browser code runs in your browser, like any web app. Both reach services through the same SDK.

One toolchain, shared by every app

Apps carry no dependencies of their own. The build stack — Vite, React, TypeScript, Tailwind — is the shared toolchain: Lodekit installs it once and every app builds against it. There is no package.json and no node_modules inside an app folder.

That single decision buys three things:

• A clean backup tree. The apps tree is source files only — a few kilobytes per app. Backing up your Lodekit root never means backing up dependency trees.
• No version drift. Every app compiles against the same React, the same Vite, the same Tailwind. Two apps can never disagree about a dependency, because neither has any.
• No installs. Creating an app is writing files. Nothing to download, nothing to resolve, nothing to audit per app.

Bundled for apps — no builds for you

Apps are bundled: when a source file is saved, the engine notices, compiles the app into static client assets plus a server bundle, and serves the result. You never run a build, and neither does your agent — saving is deploying. While that happens, the app’s card on the dashboard shows its build state: building…, then ready — or error, with details your agent can read and fix. The full lifecycle is in How Lodekit works.

Built output lands in the Cache, outside your Lodekit root — it’s regenerable, so it’s never part of what you back up.

Why one stack

Lodekit could have stayed neutral and let every app pick its own framework. It deliberately doesn’t, for two reasons.

Agents write best against one well-lit path. Your agent isn’t choosing between frameworks, state libraries, and CSS approaches on every app — the skill teaches one stack with clear guardrails, and every line it writes lands on patterns the platform was built to serve. Fewer choices, fewer novel failure modes, better code.

Every app looks and behaves like one product. Same components, same theme, same routing conventions. The tenth app your agent builds feels like a sibling of the first — and a change to the shared theme restyles all of them at once.

Next, what an app actually looks like on disk: App anatomy.