Also known as Pithecellobium tortum
Here is a wonderful addition to the indoor bonsai collection, that will thrive outdoors in the summer but must come in before the frost.
Native to Brazil, these lovely compound leaves fold up each evening or whenever the light is low. If you get one, expect it to arrive with leaves folded.
It actually belongs to the Legume family as do peas, beans and chickpeas as well as the Tamarind tree and Acacia. One of the Brazilian Raintree's best qualities as a bonsai is the trunk, both flat and twisting it shows a lot of character. Oh, and watch out for the thorns, many tropical bonsai have them and the raintree is not an exception. 
Light - Lots of Light ! As an indoor tree, keep the Brazilian raintree in a south facing window or under growlights. If you can, put it outside for the summer- at first with some shade but then after a few days this tree will take full sun in Canada. AS the nights begin to cool - late August early September bring your tree back indoors. Frost will kill it
Water- Once again you're faced with the term "evenly moist" which I personally 
hold responsible for the death of many, many bonsai. It's a little ambiguous. Ideally you water a tree well, the soils drains very well and as the growing medium moves from moist to dry you water again. So let's try- Water well. You can water from the top or the bottom- and I suggest you alternate because it is not rare for the top and sides of the soil to be wet, while the core of the rootball is bone dry. After watering let your tree drain- leave it in the sink for at least a few minutes with one side of the pot raised higher than the other ( check the bottom to make sure there is an available drainage hole. Once the pot has drained, check it every day. Look at the colour and texture of the soil, feel the surface and below the surface, lift the pot to feel the weight. As it starts to dry the soil will look lighter, the pot will weigh less and you'll feel the diffent moisture. When you think it might be ready for more- wait one more day (unless its the middle of summer and thetree is outside),
Brought back indoors, you can sit your bonsai on a pebble tree with water (not enough to reach the pot) to supplement the local humidity.
Fertilizing- Just use a simple tropical plant food, mixed to about half strength. Feed it weekly from April to October and monthly through the winter.
Training- If you decide to prune your tree, leave a small stump to avoid die back. (What's that? Trees have a way of compartmentalizing their growth, so that if a part of the tree is damaged it closes it off from the rest of the tree. ( The analogy that works for me is like closing the hatches on a flooding submarine) By leaving a stubb on the branch, you can be assured that you're not forcing the tree to "Close the hatch" lower on the trunk.
The wood is hard and difficult to bend but you can wire young branches on a Brazilian Raintree. Be careful not to leave the wire on too long because the scars will not go away. And watch out for the thorns.
Soil:
Use a well draining mix to prevent root rot.