system-text-json-net11
This skill documents new `System.Text.Json` APIs introduced in .NET 11, including strongly-typed `JsonTypeInfo<T>` access via `GetTypeInfo<T>()` and `TryGetTypeInfo<T>()` methods, plus the `JsonNamingPolicy.PascalCase` property for PascalCase serialization. Use this when serializing or deserializing JSON in .NET 11 or later projects requiring type-safe metadata access or PascalCase property naming conventions.
git clone --depth 1 https://github.com/managedcode/dotnet-skills /tmp/system-text-json-net11 && cp -r /tmp/system-text-json-net11/catalog/Platform/Official-DotNet-Dotnet11/skills/system-text-json-net11 ~/.claude/skills/system-text-json-net11SKILL.md
# System.Text.Json — .NET 11
New APIs added to `System.Text.Json` across .NET 11 releases.
## When to Use
- Serializing or deserializing JSON in a .NET 11 (or later) project
- Needing strongly-typed `JsonTypeInfo<T>` access instead of the untyped `JsonTypeInfo` overload
- Wanting to safely check whether type metadata is available without catching exceptions (`TryGetTypeInfo<T>`)
- Requiring PascalCase property naming during JSON serialization
## When Not to Use
- The project targets .NET 10 or earlier — these APIs are not available before .NET 11
- Using a JSON library that is not `System.Text.Json` (e.g., Newtonsoft.Json)
- The existing untyped `GetTypeInfo(Type)` / `TryGetTypeInfo(Type, ...)` overloads are sufficient
## Target Framework
```xml
<TargetFramework>net11.0</TargetFramework>
```
## New APIs
### Typed `JsonTypeInfo` Access
#### `JsonSerializerOptions.GetTypeInfo<T>()`
Returns a strongly-typed `JsonTypeInfo<T>` for the specified type, using the
options' configured type-info resolver.
```csharp
JsonTypeInfo<T> GetTypeInfo<T>()
```
#### `JsonSerializerOptions.TryGetTypeInfo<T>(out JsonTypeInfo<T>?)`
Attempts to retrieve typed metadata without throwing if the type is not resolved.
```csharp
bool TryGetTypeInfo<T>(out JsonTypeInfo<T>? typeInfo)
```
### `JsonNamingPolicy.PascalCase`
A new static property that converts property names to PascalCase during
serialization.
```csharp
static JsonNamingPolicy PascalCase { get; }
```
## Examples
### Get Typed JsonTypeInfo
```csharp
using System.Text.Json;
using System.Text.Json.Serialization.Metadata;
var options = new JsonSerializerOptions(JsonSerializerDefaults.Web);
// Retrieve strongly-typed metadata for MyClass
JsonTypeInfo<MyClass> typeInfo = options.GetTypeInfo<MyClass>();
Console.WriteLine($"Type: {typeInfo.Type.Name}");
```
### TryGetTypeInfo for Safe Access
```csharp
using System.Text.Json;
using System.Text.Json.Serialization.Metadata;
var options = new JsonSerializerOptions(JsonSerializerDefaults.Web);
if (options.TryGetTypeInfo<MyClass>(out var info))
{
Console.WriteLine($"Resolved type info for {info!.Type.Name}");
}
else
{
Console.WriteLine("Type info not available");
}
```
### PascalCase Naming Policy
```csharp
using System.Text.Json;
var opts = new JsonSerializerOptions
{
PropertyNamingPolicy = JsonNamingPolicy.PascalCase
};
var obj = new { firstName = "John", lastName = "Doe" };
string json = JsonSerializer.Serialize(obj, opts);
Console.WriteLine(json);
// Output: {"FirstName":"John","LastName":"Doe"}
```
### Combined: Serialize with Typed Metadata
```csharp
using System.Text.Json;
using System.Text.Json.Serialization.Metadata;
var options = new JsonSerializerOptions
{
PropertyNamingPolicy = JsonNamingPolicy.PascalCase
};
JsonTypeInfo<Person> typeInfo = options.GetTypeInfo<Person>();
string json = JsonSerializer.Serialize(new Person("Jane", 30), typeInfo);
Console.WriteLine(json);
// Output: {"Name":"Jane","Age":30}
public record Person(string Name, int Age);
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