Not credited in paper written by boss I'm a contractor hired by a software engineering company that is branching out into research. For the last two years I have been working almost solo on a research project for the company. A number of other people have come to help out on the project at some point or another, but currently all code in the codebase is written 100% by me. All of the novelties developed throughout the project were also done solo.

My boss has just written a research paper about the project which has been accepted by a low-tier journal. I got to read the paper today and while a number of my coworkers are credited, I am not. The credits consist of every non-contractor that has touched the project, as well as a number of higher ups in the company.

Furthermore, I created a number of figures used in the paper and edited the abstract.

Is this standard practice? Would it be reasonable to ask to be included in the authors list?

Edit: Just to update, my boss said that he had me in the authors list on the first draft, but when he ran it by my contracting company they said to take it off. I'm following up with them now.
As a contractor you may have explicitly or implicitly given over all of your intellectual product to the company. If that is the case then what they did is (minimally) acceptable. But in human terms it may not be proper. Certainly not "neighborly". 

Since you indicate that there is a difference in how contractors and non-contractors were treated there may be some underlying justification, valid or not, for what was done. 

I suspect that the practice is pretty common, but not universal. 

However, it would be reasonable to ask for an acknowledgement at least, and maybe authorship. You can ask, at least. You might be refused and you might be given reasons why refusal is necessary, but you gain nothing from silence. At a minimum you will learn whether it is in your best interest to continue under such a relationship.