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

# SwiftData

> PrismContainer, PrismModelStore, PrismQuery builder, and PrismLiveQuery for SwiftData integration

## PrismContainer

Factory for creating `ModelContainer` instances with sensible defaults.

```swift theme={null}
// In-memory (testing)
let container = try PrismContainer.inMemory(for: [User.self, Post.self])

// Persistent
let container = try PrismContainer.create(
    for: [User.self, Post.self],
    inMemory: false,
    cloudKitContainerID: "iCloud.com.myapp" // optional
)
```

## PrismModelStore

`@ModelActor` providing generic CRUD for any `PersistentModel`. Runs on its own `ModelContext` — safe for background work.

```swift theme={null}
let store = PrismModelStore<User>(modelContainer: container)

// Insert
await store.insert(User(name: "Alice", age: 30))

// Batch insert
let users = names.map { User(name: $0, age: 25) }
await store.insertBatch(users)

// Fetch
let all = try await store.fetch()
let adults = try await store.fetch(
    predicate: #Predicate { $0.age >= 18 },
    sortBy: [SortDescriptor(\.name)],
    limit: 50
)

// Count & exists
let count = try await store.count()
let hasUsers = try await store.exists()

// Delete
await store.delete(user)
try await store.deleteAll()

// Transaction
try await store.transaction { context in
    context.insert(User(name: "Bob", age: 28))
    context.insert(Post(title: "Hello", authorName: "Bob"))
}
```

## PrismQuery

Fluent query builder that produces a `FetchDescriptor`.

```swift theme={null}
let query = PrismQuery<User>()
    .where(#Predicate { $0.age >= 18 })
    .sort(SortDescriptor(\.name))
    .limit(20)
    .offset(40)

let descriptor = query.build()
let results = try await store.fetch(descriptor)
```

## PrismLiveQuery

Polling-based change detection. Emits count updates via `AsyncStream` — use to trigger UI re-fetches.

```swift theme={null}
let live = PrismLiveQuery<User>(
    container: container,
    descriptor: FetchDescriptor<User>(),
    interval: 2.0 // poll every 2s
)

for await count in live.countStream() {
    print("Users changed: \(count) total")
    // Re-fetch on main context
}
```

<Note>
  `countStream()` yields `Int` (not `[T]`) to avoid Sendable violations with `PersistentModel`.
</Note>