POST with application/json

[Aduen]

Why is this impossible:
<div hx-post="/update" hx-trigger='click' hx-vals='{"hello": [1,2,3], "world": {"beta": [1,2,3], "alpha": 1}}' hx-headers='{"Content-Type": "application/json"}' hx-encoding="application/json">Update</div>

It seems that a simple POST with a slightly complex JSON payload should not be this hard or am I missing something?

I have tried the hx-ext="json-enc-custom" but that doesn't seem to target this use-case.

[Aduen]

Narrowed it down to a certain JSON structure with hx-ext="json-enc" and hx-vals='{"hello": [1,2,3]}'
Causes:
TypeError: Converting circular structure to JSON --> starting at object with constructor 'Array' --- index 3 closes the circle

JSON.parse('{"hello": [1,2,3]}') works as intended
JSON.stringify({"hello": [1,2,3]}) works as intended

hx-vals='{"hello": {"world": [1,2,3]}}'
no issues

It seems that having an array in the first element causes problems. Workaround: hx-vals={"data": {_the actual object_}}

Feels like unintended behavior