Write your first plugin

This plugin adds tutorial.answer() -> i32 and returns 42.

You need Go 1.22 or newer and a standard Wago runtime.

Start the wizard

mkdir wago-answer
cd wago-answer
wago init --plugin

Answer the prompts. The wizard writes the manifest, provider catalog, Go package, and first test.

Canary dependency

If Go reports that github.com/wago-org/wago@v0.1.0 does not exist yet, point the scaffold at current canary source:

go mod edit -droprequire github.com/wago-org/wago
go get github.com/wago-org/wago@main

Request one Authority

Open register/register.go. Add this request to the generated definition:

Authorities: []wago.AuthorityRequest{{
	Name:   wago.AuthorityHostImportDefine,
	Mode:   wago.AuthorityRequired,
	Reason: "define the tutorial guest API",
	Scope:  wago.AuthorityScope{Modules: []string{"tutorial"}},
}},

The scope covers the exact import module tutorial. It does not cover parent names or wildcards.

Define the guest function

Inside Register, get the reviewed module:

imports, err := reg.HostImports()
if err != nil {
	return err
}

Then add the function:

imports.HostFunc("tutorial", "answer", func() int32 { return 42 })
return nil

Wago infers this function's no-parameter, one-i32 signature.

Check it

Format the file:

gofmt -w register/register.go

Refresh the published definition snapshot:

wago plugin catalog

Run the tests:

go test ./...

Check that the snapshot is current:

wago plugin catalog --check

The complete runnable version is examples/08-custom-plugin. Next, read Definitions and providers.