How can I avoid self-referencing loop errors when upserting a JsonObject in Couchbase using C#?

Below is an explanation of what’s happening and one recommended solution.

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What’s the Issue?

When you deserialize a JSON string into a System.Text.Json.Nodes.JsonObject, the resulting tree-like structure includes internal properties (for example, a reference to the parent node) that cause a self‐referencing loop during serialization. When Couchbase SDK (using, by default, Newtonsoft.Json for serialization) attempts to serialize this JsonObject, it gets stuck following those internal loops and throws an exception like:

  Newtonsoft.Json.JsonSerializationException: "Self referencing loop detected for property 'parent'…"

Changing JsonSerializerOptions (with Preserve or IgnoreCycles) doesn’t help because the Couchbase SDK’s serialization behavior is not affected by your local System.Text.Json options.

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Recommended Solution

If you already have a valid JSON string and only need to insert the document as JSON without double‑serialization, consider one of these options:

Option 1: Use Raw JSON with a Transcoder

Convert your JsonObject back to a JSON string (using its built‑in methods) and then tell the Couchbase SDK to treat it as already serialized JSON by using a raw JSON transcoder. For example:

CSHARPCopied
using System.Text.Json.Nodes;
using System.Text.Json;
using Couchbase.KeyValue;
using Couchbase.Core.IO.Transcoders; // Make sure you reference the correct namespace

// Assume jsonString is your raw JSON text.
string jsonString = """
    {
        "Product": "abc",
        "Price": 100
    }
    """;

// Deserialize to JsonObject (this causes the problematic tree structure).
JsonObject jsonToProduce = JsonSerializer.Deserialize<JsonObject>(jsonString);

// Convert the JsonObject back to a string.
// This call produces the intended JSON without the extra escape characters.
string rawJson = jsonToProduce.ToJsonString();

// Use RawJsonTranscoder so that the SDK does not serialize the string again.
await collection.UpsertAsync("1", rawJson,
    options => options.Transcoder(RawJsonTranscoder.Instance));

This approach tells the SDK, “Here is my JSON – please store it as is”, avoiding an extra (and problematic) serialization of the JsonObject.

Option 2: Work with a Plain Data Structure

If you don’t strictly need the JsonObject type, consider deserializing into a dictionary or an anonymous type:

CSHARPCopied
var jsonAsDictionary = JsonSerializer.Deserialize<Dictionary<string, object>>(jsonString);
await collection.UpsertAsync("1", jsonAsDictionary);

This avoids the self‑referencing properties entirely.

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Summary

• The error occurs because the JsonObject object has internal references (like “parent”) that cause a cycle during serialization.
• Simply deserializing a JSON string into a JsonObject and then passing it to UpsertAsync ends up re‑serializing the tree, which fails.
• The workaround is to convert the JsonObject back into a JSON string (using ToJsonString()) and then use the RawJsonTranscoder so Couchbase stores the string as raw JSON.
• Alternatively, deserializing into a type like Dictionary avoids the cycle issues altogether.

Choose the approach that best fits your scenario.