spacetime init my-project --lang csharp --dotnet-version 10
# From the generated module directory:
dotnet build                              # managed DLL
dotnet publish -c Release -r wasi-wasm     # NativeAOT-LLVM WASM
spacetime build                           # CLI selects WASM automatically

using SpacetimeDB;

public static partial class Module
{
    [SpacetimeDB.Table(Accessor = "ScoreRecord", Public = true)]
    public partial struct ScoreRecord
    {
        [PrimaryKey]
        [AutoInc]
        public ulong Id;
        public Identity Owner;
        public uint Value;
    }

    [SpacetimeDB.Reducer]
    public static void AddRecord(ReducerContext ctx, uint value)
    {
        ctx.Db.ScoreRecord.Insert(new ScoreRecord { Id = 0, Owner = ctx.Sender, Value = value });
    }
}

[SpacetimeDB.Table(Accessor = "Entity", Public = true)]
public partial struct Entity
{
    [PrimaryKey]
    [AutoInc]
    public ulong Id;
    [SpacetimeDB.Index.BTree]
    public Identity Owner;
    public string Name;
    [SpacetimeDB.Index.BTree]
    public bool Active;
}

[PrimaryKey]          // primary key
[AutoInc]             // auto-increment (use 0 as placeholder on insert)
[Unique]              // unique constraint; indexes the column, enables .Find()
[SpacetimeDB.Index.BTree]  // btree index (enables .Filter() on this column)
[Default(true)]       // migration-safe default for a newly appended field

// Inline (preferred for single-column):
[SpacetimeDB.Index.BTree]
public ulong AuthorId;
// Access: ctx.Db.Post.AuthorId.Filter(authorId)

// Multi-column (struct-level):
[SpacetimeDB.Table(Accessor = "Membership")]
[SpacetimeDB.Index.BTree(Accessor = "ByGroupUser", Columns = new[] { nameof(GroupId), nameof(UserId) })]
public partial struct Membership { public ulong GroupId; public Identity UserId; ... }

[SpacetimeDB.Reducer]
public static void CreateEntity(ReducerContext ctx, string name, int age)
{
    ctx.Db.Entity.Insert(new Entity { Owner = ctx.Sender, Name = name, Age = age, Active = true });
}

// No arguments:
[SpacetimeDB.Reducer]
public static void DoReset(ReducerContext ctx) { ... }

var row = ctx.Db.Entity.Insert(new Entity { Name = "Sample" });   // Insert; returns the row with AutoInc fields assigned
ctx.Db.Entity.Id.Find(entityId);                                  // Find by PK → Entity? (nullable)
ctx.Db.Entity.Identity.Find(ctx.Sender);                          // Find by unique column → Entity?
if (ctx.Db.Entity.Id.Find(entityId) is { } entity) { ... }        // unwrap Entity? before member access
ctx.Db.Item.AuthorId.Filter(authorId);                            // Filter by index → IEnumerable<Item>
ctx.Db.Entity.Iter();                                             // All rows → IEnumerable<Entity>
ctx.Db.Entity.Count;                                              // Count rows
ctx.Db.Entity.Id.Update(existing with { Name = newName });        // Update by PK
ctx.Db.Entity.Id.Delete(entityId);                                // Delete by PK

[SpacetimeDB.Reducer(ReducerKind.Init)]
public static void OnInit(ReducerContext ctx) { ... }

[SpacetimeDB.Reducer(ReducerKind.ClientConnected)]
public static void OnConnect(ReducerContext ctx) { ... }

[SpacetimeDB.Reducer(ReducerKind.ClientDisconnected)]
public static void OnDisconnect(ReducerContext ctx) { ... }

// Anonymous view (same result for all clients):
[SpacetimeDB.View(Accessor = "ActiveUsers", Public = true)]
public static List<Entity> ActiveUsers(AnonymousViewContext ctx)
{
    return ctx.Db.Entity.Active.Filter(true).ToList();
}

// Per-user view:
[SpacetimeDB.View(Accessor = "MyEntities", Public = true)]
public static List<Entity> MyEntities(ViewContext ctx)
{
    return ctx.Db.Entity.Owner.Filter(ctx.Sender).ToList();
}

ctx.From.Article().Where(article => article.Published.Eq(true));
ctx.From.Subscription().RightSemijoin(
    ctx.From.Account(),
    (subscription, account) => subscription.AccountId.Eq(account.Id)
);

[SpacetimeDB.View(Accessor = "EntityById", Public = true)]
public static Entity? EntityById(AnonymousViewContext ctx, ulong id) =>
    ctx.Db.Entity.Id.Find(id);

[ClientVisibilityFilter]
public static readonly Filter PrivateNoteFilter = new Filter.Sql(
    "SELECT * FROM OwnedRow WHERE Owner = :sender"
);

// Auth: ctx.Sender is the caller's Identity
if (row.Owner != ctx.Sender)
    throw new Exception("unauthorized");

// Server timestamp (deterministic per reducer call)
ctx.Db.Item.Insert(new Item { CreatedAt = ctx.Timestamp, .. });

// Timestamp arithmetic
var expiry = ctx.Timestamp + new TimeDuration(delayMicros);

// Deterministic RNG
int roll = ctx.Rng.Next(1, 7);          // [1, 7): inclusive 1, exclusive 7
double f = ctx.Rng.NextDouble();        // [0.0, 1.0)

// Timestamp → milliseconds since epoch
timestamp.MicrosecondsSinceUnixEpoch / 1000

// Root Lib.cs, before namespace/type declarations:
[assembly: SpacetimeDB.Namespace(typeof(AuthLib.Marker), Accessor = "MyAuth", Name = "auth_data")]

[SpacetimeDB.Env]
public partial struct EnvironmentSchema
{
    public string API_KEY;
    [SpacetimeDB.EnvValues("development", "production")]
    public string MODE;
    public string? LOG_LEVEL;
}
// In a root entry point:
// ctx.Env.API_KEY: string; ctx.Env.LOG_LEVEL: string?
// ctx.Env.Get("LOG_LEVEL"): string?

[SpacetimeDB.Table(
    Accessor = "TickTimer",
    Scheduled = nameof(Tick),
    ScheduledAt = nameof(ScheduledAt),
    Public = true
)]
public partial struct TickTimer
{
    [PrimaryKey]
    [AutoInc]
    public ulong ScheduledId;
    public ScheduleAt ScheduledAt;
}

[SpacetimeDB.Reducer]
public static void Tick(ReducerContext ctx, TickTimer timer)
{
    // timer row is auto-deleted after this reducer runs
}

// One-time: fires once at a specific time
var at = new ScheduleAt.Time(ctx.Timestamp + new TimeDuration(10_000_000));
// Repeating: fires on an interval
var at = new ScheduleAt.Interval(TimeSpan.FromSeconds(5));

ctx.Db.TickTimer.Insert(new TickTimer { ScheduledId = 0, ScheduledAt = at });

[SpacetimeDB.Type]
public partial struct ResultValue { public string Value; }

[SpacetimeDB.Procedure]
public static ResultValue Inspect(ProcedureContext ctx, string input) =>
    new() { Value = input };

var result = ctx.Http.Get(uri);
var text = result.Match(
    response => response.Body.ToStringUtf8Lossy(),
    error => throw new Exception(error.Message)
);

ctx.WithTx(tx =>
{
    tx.Db.ScoreRecord.Insert(new ScoreRecord { Id = 0, Owner = ctx.Sender, Value = 1 });
    return 0;
});

var result = ctx.Http.Send(new HttpRequest
{
    Uri = uri,
    Method = SpacetimeDB.HttpMethod.Post,
    Headers = new() { new HttpHeader("content-type", "text/plain") },
    Body = HttpBody.FromString(payload),
});

[SpacetimeDB.HttpHandler]
public static HttpResponse Health(HandlerContext ctx, HttpRequest request) => new(
    200, HttpVersion.Http11, new(), HttpBody.FromString("ok")
);

[SpacetimeDB.HttpRouter]
public static Router Routes() => SpacetimeDB.Router.New().Get("/health", Handlers.Health);

[SpacetimeDB.Type]
public enum Status { Online, Away, Offline }

[SpacetimeDB.Type]
public partial struct Point { public float X; public float Y; }

[SpacetimeDB.Type]
public partial struct Circle { public int Radius; }

[SpacetimeDB.Type]
public partial struct Rectangle { public int Width; public int Height; }

[SpacetimeDB.Type]
public partial record Shape : SpacetimeDB.TaggedEnum<(Circle Circle, Rectangle Rectangle)> { }

// Construct variants via the generated nested constructors:
var a = new Shape.Circle(new Circle { Radius = 10 });
var b = new Shape.Rectangle(new Rectangle { Width = 4, Height = 6 });