# FieldHeaderCodec.ReadFieldHeader(Reader<TInput>)

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.serialization/orleans.serialization.codecs.fieldheadercodec/) | [Methods](/orleans/docs/api/csharp/microsoft.orleans.serialization/orleans.serialization.codecs.fieldheadercodec/methods/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Serialization/Buffers/Writer.FieldHeader.cs#L124-L138)

```csharp
public static Field ReadFieldHeader<TInput>(this ref Reader<TInput> reader)
```

Reads a field header.

### Parameters

- `reader` (`Reader<TInput>`): The reader.

### Returns

The field header.