you can add vendors while creating.

src/clj/auto_ap/graphql/invoices.clj

@@ -1,21 +1,27 @@
 (ns auto-ap.graphql.invoices
   (:require [auto-ap.graphql.utils :refer [->graphql]]
             [auto-ap.db.invoices :as invoices]
+            [auto-ap.db.vendors :as vendors]
             [auto-ap.db.invoices-expense-accounts :as invoices-expense-accounts]
             [auto-ap.time :refer [parse normal-date]]))
 
-(defn add-invoice [context {{:keys [total invoice_number company_id vendor_id date] :as in} :invoice} value]
+(defn -create-vendor-if-necessary [vendor-id vendor-name]
+  (if vendor-id
+    vendor-id
+    (:id (doto (vendors/insert {:name vendor-name :default-expense-account 0}) println))))
 
-  (-> (invoices/insert-multi! [{:invoice-number invoice_number
-                                :company-id company_id
-                                :vendor-id vendor_id
-                                :total total
-                                :outstanding-balance total
-                                :status "unpaid"
-                                :imported true
-                                :date (parse date normal-date)}])
-      (first)
-      (->graphql)))
+(defn add-invoice [context {{:keys [total invoice_number company_id vendor_id vendor_name date] :as in} :invoice} value]
+  (let [vendor_id (-create-vendor-if-necessary vendor_id vendor_name)]
+    (-> (invoices/insert-multi! [{:invoice-number invoice_number
+                                  :company-id company_id
+                                  :vendor-id vendor_id
+                                  :total total
+                                  :outstanding-balance total
+                                  :status "unpaid"
+                                  :imported true
+                                  :date (parse date normal-date)}])
+        (first)
+        (->graphql))))
 
 
 (defn get-invoices-expense-accounts [context args value]