Hi Kdy, depending on the agreement with the broker, the landlord may pay the fee or it may fall upon the renter. However, the fee is fairly reasonable. Usually it amounts to either 10% of the annual rent or one month's rental fee.
For reasons why it makes sense to hire a realtor, you can read my blog, Top 10 Reasons to Hire a Real Estate Agent. Link below!
If you are still looking for an agent, contact me (click on my name) and leave me your full name and phone number and what you are looking for. I will connect you will an excellent colleague of mine who services Oklahoma City.