City Raid rewards are collected manually after the step is complete. You will have until the next City Raid to claim the award. Once the next City Raid begins, the rewards are lost.
The rewards may include but are not limited to fame stars, gems, keys, special blueprints, Crown Jewels, items etc.
The exclusive blueprints are the prizing for completing the final step in a City Raid. Once you receive this reward, it will change to a Primal Chest reward should that exact Raid occurs again.
Example: Should you complete the Deadly Swarm raid, the first completion will yield a Wind Piercer Blueprint. The next time Deadly Swarm is played, the second completion will yield a Primal Chest.