Commodore Henry Gallant (The Henry Gallant Saga Book 6) Amazon
 

A gigantic Unidentified Flying Object materializes over the capital of Earth - terrifying the world.

The ancient Chameleon race wants to work with Humans to stop the genocidal Titans. The Chameleon are humanoid but have an AI chip implanted in their brain which gives them unique abilities.

Henry Gallant's exceptional ability to interface with AI makes him the key to negotiate a mutual defense treaty and obtain the alien's superior stealth technology. Using the advanced tech, Gallant leads a raid against the Titan's homeworld.

For Fans of Gattaca and Horatio Hornblower.