question regarding seller agent contract

What is the name of your state? California

hello,

I live in San Jose,CA, USA.
I plan to go back to France.
I should receive my work contrat within 1 or 2 weeks.
I contacted a real estate agent to put my house for sale.
I signed all the documents in advance (agreement on a listed price of $758,888, commission of 4.5% or 3.5% if he also is the buyer agent).
I asked him not to put the house for sale until I call him to let him know that I got the work contract and we can proceed.
He has not done anything yet (advertising, photos, etc...) but probably has started the documentation work.

Now I have the brother of my neighbor ready to buy the house.
He would like to do it between us without real estate agent to save on the commissions.
His father in law has a real estate license and would do the paper work for free.

Is it legal?
Can I just say to my seller agent I don't want to proceed and then sell the house directly to my buyer?

If Legally I am stuck with my seller agent, for how long or can I renegociate the commission because I bringthe buyer and he does not need to do anything?

Advices apreciated, thank you

[HomeGuru]

duplicate post.