The Fluent API configuration is made possible because Microsoft has exposed a series of extension methods, which allows us to execute appropriate functionality against the property of the model that supports it. In our blogging system, we will configure the Url of the Post entity as the concurrency token by enabling the property using IsConcurrencyToken() as shown in the following code:

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
      // Code removed for brevity
      modelBuilder.Entity<Post>()
        .ToTable("Post")
        .Property(x=>x.Url)
        .IsConcurrencyToken();
      // Code removed for brevity
    }

The preceding configuration will let EF Core consider the Url column as the concurrency token, and any further update to this column will restrict users from performing parallel updates, as it did in the data annotation configuration.

We have exhaustively seen how this concurrency token works, so let's move on to the next section that explores timestamp-based concurrency tokens.