diff --git a/api/v1/accounts/lookup/handler.go b/api/v1/accounts/lookup/handler.go
new file mode 100644
index 0000000..49dbe4f
--- /dev/null
+++ b/api/v1/accounts/lookup/handler.go
@@ -0,0 +1,78 @@
+package lookup
+
+import (
+	"net/http"
+
+	"sourcecode.social/reiver/go-mstdn"
+	"sourcecode.social/reiver/go-mstdn/ent"
+)
+
+var _ http.Handler = Handler{}
+
+const Path string = "/api/v1/accounts/lookup"
+
+type Handler struct {
+	LoaderFunc LoaderFunc
+}
+
+func (Handler) Path() string {
+	return Path
+}
+
+func (receiver Handler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
+	if nil == resp {
+		return
+	}
+
+	if nil == req {
+		mstdn.InternalServerError(resp)
+		return
+	}
+
+	if http.MethodGet != req.Method {
+		mstdn.MethodNotAllowed(resp)
+		return
+	}
+
+	fn := receiver.LoaderFunc
+	if nil == fn {
+		mstdn.InternalServerError(resp)
+		return
+	}
+
+	var acct string
+	{
+		const key string = "acct"
+
+		url := req.URL
+		if nil == url {
+			mstdn.InternalServerError(resp)
+			return
+		}
+
+		query := url.Query()
+		if nil == query {
+			mstdn.InternalServerError(resp)
+			return
+		}
+
+		if !query.Has(key) {
+			mstdn.BadRequest(resp)
+			return
+		}
+
+		acct = query.Get("acct")
+	}
+
+	var account ent.Account
+	{
+
+		err := fn(&account, acct)
+		if nil != err {
+			mstdn.Error(resp, err.ErrHTTP())
+			return
+		}
+	}
+
+	mstdn.OK(resp, account)
+}
diff --git a/api/v1/accounts/lookup/loader.go b/api/v1/accounts/lookup/loader.go
new file mode 100644
index 0000000..732ae4d
--- /dev/null
+++ b/api/v1/accounts/lookup/loader.go
@@ -0,0 +1,8 @@
+package lookup
+
+import (
+	"sourcecode.social/reiver/go-mstdn/api/v1"
+	"sourcecode.social/reiver/go-mstdn/ent"
+)
+
+type LoaderFunc func(account *ent.Account, acct string) v1.Error