Kanye seemed thrilled he was able to show up to the shindig but said it was Travis Scott who told him the party was being thrown at Kylie's home. He also thanked Kris and Corey ... and Kylie for letting him in, but made no mention of Kim. He also groused that security stopped him briefly at the door.

He was clearly happy, saying his kids are the priority in his life ... and you can see and hear he really seems to mean it. We're told he spent about 2 hours there.

The party looked super fun, and Kanye is smiling as he chatted with some of the guests. You can see Kanye and Kim in the same shot, but they are not together.

As we reported, Kanye accused Kim earlier in the day of keeping him from seeing Chi on her birthday -- he says she refused to give him the address of the party -- and claimed it was an example of how fathers have been kept out of the family unit.

Our Kim sources say this was a simple case of crossed signals, and she never wanted to exclude him. The sources say Kim and Kanye discussed having 2 parties for Chicago, and Kanye was supposed to throw the second one after 4 PM when he picked her up.