FullItem

One base class that combines etags, timestamps, and time-to-live.

FullItem combines every behavior offered by the smaller bases:

IItem — Id, Type, and partition-key handling (from Item).
IItemWithEtag — optimistic concurrency control via Etag.
IItemWithTimeStamps — CreatedTimeUtc, LastUpdatedTimeUtc, and LastUpdatedTimeRaw.
IItemWithTimeToLive — per-item TimeToLive overriding the container default.

If you want the works without thinking about it, derive from FullItem.

using Microsoft.Azure.CosmosRepository;
using Microsoft.Azure.CosmosRepository.Attributes;

namespace OptimisticConcurrencyControl;

[Container("accounts")]
[PartitionKeyPath("/id")]
public class BankAccount : FullItem
{
    public string Name { get; set; } = string.Empty;
    public double Balance { get; set; }

    public void Withdraw(double amount)
    {
        if (Balance - amount < 0.0)
            throw new InvalidOperationException("Cannot go overdrawn");

        Balance -= amount;
    }

    public void Deposit(double amount) => Balance += amount;

    public override string ToString() =>
        $"Account (Name = {Name}, Balance = {Balance}, Etag = {Etag})";
}

When you don’t want everything

FullItem is the most expressive base, but it’s also the most opinionated. Pick a smaller base when:

Need	Base class
Only optimistic concurrency	`EtagItem`
Only timestamps	`TimeStampedItem`
Only TTL overrides	`TimeToLiveItem`
Custom mix	Implement the matching `IItemWith*` interfaces yourself