(HTTPie maintainer here)

You might be in luck since Nested JSON support is going to be star feature of our upcoming release. Here is a sneak peek:

$ http --offline --print=B pie.dev/post \ search[type]=client \ search[stars]:=50000 \ search[platforms][]=Web \ search[platforms][]=Desktop \ search[platforms][]=Mobile \ search[platforms][]=CLI

{ "search": { "platforms": [ "Web", "Desktop", "Mobile", "CLI" ], "stars": 50000, "type": "client" } }

We are rolling a brand-new mini-language that integrates really well with the existing request building syntax, but also features stuff like JSON type-safety and amazing error messages for basic syntax errors.