Payload conversion - .NET SDK

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Payload conversion

Temporal SDKs provide a default Payload Converter that can be customized to convert a custom data type to Payload and back.

Conversion sequence

The order in which your encoding Payload Converters are applied depend on the order given to the Data Converter. You can set multiple encoding Payload Converters to run your conversions. When the Data Converter receives a value for conversion, it passes through each Payload Converter in sequence until the converter that handles the data type does the conversion.

Payload Converters can be customized independently of a Payload Codec. Temporal's Converter architecture looks like this:

Temporal converter architecture

Custom Payload Converter

Data converters are used to convert raw Temporal payloads to/from actual .NET types. A custom data converter can be set via the DataConverter option when creating a client. Data converters are a combination of payload converters, payload codecs, and failure converters. Payload converters convert .NET values to/from serialized bytes. Payload codecs convert bytes to bytes (e.g. for compression or encryption). Failure converters convert exceptions to/from serialized failures.

Data converters are in the Temporalio.Converters namespace. The default data converter uses a default payload converter, which supports the following types:

• null
• byte[]
• Google.Protobuf.IMessage instances
• Anything that System.Text.Json supports
• IRawValue as unconverted raw payloads

Custom converters can be created for all uses. For example, to create client with a data converter that converts all C# property names to camel case, you would:

using System.Text.Json;
using Temporalio.Client;
using Temporalio.Converters;

public class CamelCasePayloadConverter : DefaultPayloadConverter
{
    public CamelCasePayloadConverter()
      : base(new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase })
    {
    }
}

var client = await TemporalClient.ConnectAsync(new()
{
    TargetHost = "localhost:7233",
    Namespace = "my-namespace",
    DataConverter = DataConverter.Default with { PayloadConverter = new CamelCasePayloadConverter() },
});