Some APIs are already implemented and are documented in here
http://wiki.nxtcrypto.org/wiki/Nxt_API#Asset_exchange_operations
I would think that we need at least:
- Get AssetID by Asset Name - an API call by passing asset name to give back assetID
- Get AssetIDs by AccountID - an API call by passing an account id to show all the assets owned by the account
- Get BID_ASK Orders by Asset ID- an API call by passing an asset id to show all bid_ask orders for the asset so we can build order book.
Please add more API Asset requests.
EDIT: THERE IS A THREAT ALREADY DISCUSSING API SO USE IT INSTEAD: https://bitcointalk.org/index.php?topic=406839.40