Seems to be a basic question but I am yet to find a solution that would feel idiomatic, that being said, If I want my convention plugin to work with or rely on other plugins information this is an obvious solution

project.pluginManager.withPlugin

But what if I need several plugins to be applied beforehand, for example both agp and kgp? What's the right approach? Is there an API I am missing? Or is the API itself seems to be missing?

You set a flag in each

withPlugin{}

block and then you do an

afterEvaluate {}

that fails if not all your flags are set

That's what I always did but I wish there would be a better way like vararg

withPlugins

No, this is not a valid use-case for

afterEvaluate

, just nest the

withPlugin

calls if you need both.

pluginManager.withPlugin("<kgp>") {
    pluginManager.withPlugin("<agp>") {
        // do what needs both plugins applied
    }
}

this is not a valid use-case for

afterEvaluate

You need

afterEvaluate{}

if you need to fail if the plugins are not applied (which I agree is not part of the original question but often related)

If you need to fail if the plugins are not applied, you should instead apply the plugins and not react to them being applied 🙂

Not if you want the user to control the version

Why not? You can just apply the version that was added by the user to the classpath or that he already applied

Yeayea but if that's not in the classpath it's going to fail with a weird message

Check whether the plugin class is available and throw a meaningful error if it is not found in the classpath 🙂

That works. I'm all for not using

afterEvaluate{}

TBH.

This is one of the only valid use cases of

afterEvaluate{}

No, not really, you should chain the with plugins together!