Is it OK to ask your supervisor for a recommendation for attending an academic event if the PhD just started? I just began my PhD this week.
There is a very important event that will take place next month and there are some stipends for attending PhD students, but the deadline to apply for such stipends is in one week.
As usual, it is required that the supervisor writes a short "support letter" to the program chair.

The thing is that I just started my PhD something like five days ago, and this is my first time working with my supervisor. I have experience with the topics that will be covered in the event and I consider it is important for me to attend.


  With this in mind, should I ask my supervisor for a letter?


I was thinking in asking him for his opinion rather than the letter, would this be better?

Thanks in advance!
Rather than just ask for the support letter, it may be a good step to simply ask if your supervisor thinks that the event is appropriate for you to participate in, given your knowledge of the topic and ability to prepare for the event (if applicable, I'm not sure if the event is something you would have to prepare for, like a conference). Your supervisor may be happy that you are demonstrating such enthusiasm and effort early in your program of study!

Since the deadline is short, I would offer to draft the letter for him. This will help with the timing, plus it will help since you have not worked together very long. This will ease the burden of the task, which he will also appreciate. Good luck!