> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aiparlance.org/llms.txt
> Use this file to discover all available pages before exploring further.

# CRUD walkthrough

> Build a complete blog CRUD in .aip — entities, policies, API, seeds, and emit

# CRUD walkthrough

End-to-end path from a multi-entity `.aip` to Preview artifacts. Canonical example: [`examples/blog-crud.aip`](https://github.com/eudameron/aiparlance/blob/main/examples/blog-crud.aip).

Related: [`inventory-crud.aip`](https://github.com/eudameron/aiparlance/blob/main/examples/inventory-crud.aip) (stock moves + workers) · [`mysql-minimal.aip`](https://github.com/eudameron/aiparlance/blob/main/examples/mysql-minimal.aip) (MySQL).

***

## 1. App + auth

```aip theme={null}
app Blog @0.1 {
  database postgres
  auth jwt
}
```

***

## 2. Entities and CRUD

Define the graph, then declare `crud` for each resource you want as an HTTP resource:

```aip theme={null}
entity Author {
  timestamps
  soft_delete
  name: string required
  email: email required unique
  role: enum(admin, editor, writer) default(writer)
}

entity Post {
  timestamps
  soft_delete
  title: string required
  slug: string required unique
  body: text required
  status: enum(draft, published, archived) default(draft)
  author: belongs_to Author
}

entity Comment {
  timestamps
  body: text required
  post: belongs_to Post
  author: belongs_to Author optional
}

crud Author
crud Post
crud Comment
```

***

## 3. Validation, policy, index, API

```aip theme={null}
validation Post {
  title required
  slug required unique
  body required
}

policy Post {
  create authenticated
  read public
  update owner_or_manager(Post.author)
  delete role(admin)
}

index Post {
  status
  slug
}

api {
  prefix "/v1"
  format json
  rate_limit 120/minute
}
```

OpenAPI paths become `/v1/authors`, `/v1/posts`, `/v1/comments` (and `/{id}` variants).

***

## 4. Seed + light Behavior

```aip theme={null}
seed Author {
  name: "Site Admin"
  email: "admin@blog.example.com"
  role: admin
}

workflow PostPublished {
  when Post.updated
  notify(Post.author, "Post status may have changed")
  emit PostStatusChanged {
    post: Post
    author: Post.author
  }
}

event PostStatusChanged {
  post: Post
  author: Author
}
```

***

## 5. Validate and emit

```bash theme={null}
npm ci && npm run build

node packages/cli/dist/cli.js validate examples/blog-crud.aip

node packages/cli/dist/cli.js emit sql examples/blog-crud.aip
node packages/cli/dist/cli.js emit openapi examples/blog-crud.aip
node packages/cli/dist/cli.js emit typescript examples/blog-crud.aip
node packages/cli/dist/cli.js emit go examples/blog-crud.aip
node packages/cli/dist/cli.js emit tests examples/blog-crud.aip
node packages/cli/dist/cli.js emit docs examples/blog-crud.aip
```

Expect PostgreSQL tables for authors/posts/comments, indexes, a seed `INSERT`, and OpenAPI CRUD under `/v1`.

For MySQL:

```bash theme={null}
node packages/cli/dist/cli.js emit mysql examples/mysql-minimal.aip
```

For jobs/queues (inventory example):

```bash theme={null}
node packages/cli/dist/cli.js emit workers examples/inventory-crud.aip
```

***

## Checklist

* [ ] One `app` with `database` (+ `auth` if needed)
* [ ] Entities with relations + `crud` per resource
* [ ] `validation` / `policy` / `index` / `api` as needed
* [ ] Optional `seed`, `workflow`, `event`
* [ ] `aip validate` green before emit
* [ ] Review Preview artifacts before shipping

Next: [Get started here](/en/getting-started) · [First emitters](/en/first-transpiler) · [Security](/en/security) · [Workflows](/en/workflows)