How to play co-op through GMOD? Or any other way?

[awesomek29]

I and my friend bought Portal 1 on sale and would like to play co-op together, could anyone show us how? ( We have Portal 2 also)

[Mλrtin2H]

As far as I'm aware no one has made a stable co-op mod for Portal 1, so yeah, I guess GMOD. But I don't know how fun that would be sense Portal 1 is only meant for one person.
Portal 2 has built in co-op.

[awesomek29]

I tried GMOD but it spawns me in with a gravity gun and GLaDOS never speaks

[harry]

Portal does not have co-op. Portal 2, however, does. You can invite people to a Portal 2 co-op game through Steam Chat.

[Socks with jandals]

i heard there wsa an unofficial way to play portal 2 campaign in co op instead of the standalone co op modes. is that true, and how do you do it?

[Mλrtin2H]

Originally posted by Socks with jandals:

i heard there wsa an unofficial way to play portal 2 campaign in co op instead of the standalone co op modes. is that true, and how do you do it?

You mean to play the single player campain in co-op? Here you go:
https://steamcommunity.com/sharedfiles/filedetails/?id=1234281600

[Arch Dornan]

almost everything except pellets turrets and the end fight work