Yeah the 1.0 spec is a bit strange. JSON-RPC 2.0 pins it down quite nicely: a list of requests begets a list of responses. Afaik, none of the JSON-RPC client libraries handle the error code. They all just look at the “error” field of the JSON-RPC response. At the very least, I would return 200 if ANY of the requests succeed.
Re: JSON-RPC Multiple Invocations
Figures: lachesis