# Project structure

URL: https://docs.domainruntime.dev/docs/introduction/project-structure
Status: Planned
Reviewed: 2026-09-22



<div className="docs-note">
  **Planned layout.**

   

  `create-app`

   today also generates 

  `src/runtime.ts`

  , 

  `instant.schema.ts`

   and an 

  `/api/domain`

   route for the standalone adapter; 

  `druntime`

   does not need them.
</div>

```text
my-app/
├─ src/
│  ├─ domain.ts              your domain: entities, links, actions
│  ├─ lib/db.ts              the browser client, typed from the domain
│  └─ app/                   your Next.js app
├─ .domainruntime/
│  ├─ dev.json               what druntime runs: domain entry and client commands
│  ├─ link.json              the project and environment this folder is linked to (druntime link)
│  └─ dev-session.json       the running development session (not in git)
├─ .env.local                DOMAIN_RUNTIME_URL and public configuration, written by druntime (not in git)
├─ DOMAIN.md                 your business in plain words, for people and agents
└─ package.json
```

## `src/domain.ts` [#srcdomaints]

The source of truth. The database schema, the typed client and the action endpoints are derived from it. Keep it free of UI code: it runs in the runtime, not in the browser.

For a larger product, split it and compose:

```text
src/domain/
├─ index.ts        export default the root domain
├─ orders.ts       domain("orders").withSchema({…}).withActions({…})
└─ billing.ts      domain("billing").includes(orders).withSchema({…}).withActions({…})
```

## `.domainruntime/dev.json` [#domainruntimedevjson]

```json
{
  "name": "my-app",
  "domain": "src/domain.ts",
  "clients": [
    { "name": "web", "cwd": ".", "command": ["pnpm", "run", "dev"] }
  ]
}
```

`clients` lists the commands `druntime` starts and gives the environment's URL. Add an Expo or desktop app the same way. See [Local development](/docs/environments/local-development).

## Naming [#naming]

* Domain names are camelCase: `orders`, `supplierNetwork`.
* Entities are prefixed with their domain: `orders_order`, `orders_lineItem`. Entities share one namespace per environment and domains are composed, so the prefix keeps them apart and tells a reader which domain owns each one.
* Action ids are `<domain>.<action>`: `orders.place`.