diff --git a/internal/rosa/go.go b/internal/rosa/go.go
new file mode 100644
index 0000000..431ea1a
--- /dev/null
+++ b/internal/rosa/go.go
@@ -0,0 +1,77 @@
+package rosa
+
+import (
+	"slices"
+
+	"hakurei.app/internal/pkg"
+)
+
+// newGoBootstrap returns the Go bootstrap toolchain.
+func (t Toolchain) newGoBootstrap() pkg.Artifact {
+	const checksum = "8o9JL_ToiQKadCTb04nvBDkp8O1xiWOolAxVEqaTGodieNe4lOFEjlOxN3bwwe23"
+	return t.New("go1.4-bootstrap", nil, nil, []string{
+		"CGO_ENABLED=0",
+	}, `
+mkdir -p /var/tmp
+cp -r /usr/src/go1.4-bootstrap /work
+cd /work/go1.4-bootstrap/src
+chmod -R +w ..
+CC="${CC} ${LDFLAGS}" sh make.bash
+`, pkg.Path(AbsUsrSrc.Append("go1.4-bootstrap"), false, pkg.NewHTTPGetTar(
+		nil, "https://dl.google.com/go/go1.4-bootstrap-20171003.tar.gz",
+		mustDecode(checksum),
+		pkg.TarGzip,
+	)))
+}
+
+// newGo returns a specific version of the Go toolchain.
+func (t Toolchain) newGo(
+	version, checksum string,
+	boot pkg.Artifact,
+	env ...string,
+) pkg.Artifact {
+	return t.New("go"+version, []pkg.Artifact{
+		boot,
+	}, nil, slices.Concat([]string{
+		"GOCACHE=/tmp/gocache",
+		"GOROOT_BOOTSTRAP=/system/go",
+		"CGO_" + ldflags(false) + " -O2 -g",
+	}, env), `
+mkdir /work/system
+cp -r /usr/src/go /work/system
+cd /work/system/go/src
+chmod -R +w ..
+sed -i 's/bash run.bash/sh run.bash/' all.bash
+sh make.bash
+`, pkg.Path(AbsUsrSrc.Append("go"), false, pkg.NewHTTPGetTar(
+		nil, "https://go.dev/dl/go"+version+".src.tar.gz",
+		mustDecode(checksum),
+		pkg.TarGzip,
+	)))
+}
+
+// NewGo returns a [pkg.Artifact] containing the Go toolchain.
+func (t Toolchain) NewGo() pkg.Artifact {
+	go119 := t.newGo(
+		"1.19",
+		"9_e0aFHsIkVxWVGsp9T2RvvjOc3p4n9o9S8tkNe9Cvgzk_zI2FhRQB7ioQkeAAro",
+		t.newGoBootstrap(),
+		"GOROOT_BOOTSTRAP=/go1.4-bootstrap",
+	)
+	go121 := t.newGo(
+		"1.21.13",
+		"YtrDka402BOAEwywx03Vz4QlVwoBiguJHzG7PuythMCPHXS8CVMLvzmvgEbu4Tzu",
+		go119,
+	)
+	go123 := t.newGo(
+		"1.23.12",
+		"wcI32bl1tkqbgcelGtGWPI4RtlEddd-PTd76Eb-k7nXA5LbE9yTNdIL9QSOOxMOs",
+		go121,
+	)
+	go125 := t.newGo(
+		"1.25.6",
+		"x0z430qoDvQbbw_fftjW0rh_GSoh0VJhPzttWk_0hj9yz9AKOjuwRMupF_Q0dbt7",
+		go123,
+	)
+	return go125
+}