Json5 1.0.4

A JSON5 parser for .NET built entirely on top of the public System.Text.Json API surface. Requires .NET 10+.

Usage

Parse to JsonNode

using Json5;

JsonNode? node = Json5.Parse("""
    {
        // comments are allowed
        unquoted: 'single-quoted string',
        hex: 0xDECAF,
        leadingDot: .5,
        trailing: 'comma',
    }
    """);

Deserialize to a typed object

var config = Json5.Deserialize<AppConfig>(json5String);

Parse to JsonDocument

using var doc = Json5.ParseDocument(json5String);
JsonElement root = doc.RootElement;

Convert to standard JSON

string json = Json5.ToJson(json5String);
byte[] utf8 = Json5.ToUtf8Json(json5Bytes);

Write to Utf8JsonWriter

Json5.WriteTo(json5String, writer);

JSON5 Features

All JSON5 extensions beyond standard JSON are supported:

Auto-Dedent Multi-line Strings

When parsing multi-line string values, you can automatically remove common leading whitespace via Json5ReaderOptions.AutoDedent. This makes it easier to write readable indented code without the indentation appearing in the final string value.

var options = new Json5ReaderOptions { AutoDedent = true };
var node = Json5.Parse("""
    {
        description: '
            This is a multi-line string
            with consistent indentation
            that will be removed.
        '
    }
    """, options);
// description will be: "This is a multi-line string\nwith consistent indentation\nthat will be removed."

The algorithm:

1. Strips the first line if blank
2. Strips the last line if blank
3. Finds the minimum common leading whitespace across all remaining non-blank lines
4. Removes that minimum indent from every line

Only string values are affected; property names are never dedented. Blank lines within the string are preserved.

Infinity / NaN Handling

Since standard JSON has no representation for Infinity and NaN, the behavior is configurable via Json5ReaderOptions.SpecialNumbers:

var options = new Json5ReaderOptions 
{ 
    SpecialNumbers = SpecialNumberHandling.AsNull 
};
var node = Json5.Parse("Infinity", options); // returns null

Open Source Maintenance Fee

To ensure the long-term sustainability of this project, users of this package who generate revenue must pay an Open Source Maintenance Fee. While the source code is freely available under the terms of the License, this package and other aspects of the project require adherence to the Maintenance Fee.

To pay the Maintenance Fee, become a Sponsor at the proper OSMF tier. A single fee covers all of Devlooped packages.

Sponsors

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