The problem is, the :content_cb callback gets called with odd sized chunks of data as they are received, and if you pass those to inflate(), you just get ' data error'.

I've tried accumulating the odd sized chunks as they arrive, and passing the buffer to inflate() as they accumulate, but it has never actually decoded anything until the entire request has completed.

And if you have to accumulate the entire content before decoding it, you might as well skip the callback and let LWP decode it for you.