I completely agree with your opinion on this matter.

I agree to your proposal.

They agreed on the terms of the contract.

I couldn't agree more with you.

I cannot agree with you more.

They reached an agreement on the terms of the contract.

They made a gentleman's agreement to settle the matter peacefully.

I am in agreement with your proposal.

The two countries signed a security agreement to ensure mutual defense.

The defendant reached a plea agreement with the prosecution.