Is there any database of Autonomous Systems (AS) and IP address spaces an AS is allocated?

Question

as IP address spaces are allocated to different ASes, there must be an API or database somewhere where I can find all addresses an AS can originate ?

Answer 1

Yes there is such a database. You can find it on the RIPE web site. There is also an API to query the database with your custom application:

https://labs.ripe.net/ripe-database/database-api/api-introduction

or if you just need to search from the web page you can use the search button at this page:

http://www.ripe.net/data-tools/db