diff --git a/test/aprsme_web/live/api_docs_live_test.exs b/test/aprsme_web/live/api_docs_live_test.exs
index f6fb452..0d415db 100644
--- a/test/aprsme_web/live/api_docs_live_test.exs
+++ b/test/aprsme_web/live/api_docs_live_test.exs
@@ -1,6 +1,7 @@
 defmodule AprsmeWeb.ApiDocsLiveTest do
   use AprsmeWeb.ConnCase
 
+  import Aprsme.PacketsFixtures
   import Phoenix.LiveViewTest
 
   describe "ApiDocsLive" do
@@ -74,5 +75,37 @@ defmodule AprsmeWeb.ApiDocsLiveTest do
       # packet result. Both exercise the happy path of make_http_request.
       assert rendered =~ "No packets found" or rendered =~ "data"
     end
+
+    test "valid callsign with existing packet returns JSON data", %{conn: conn} do
+      # Create a packet in the DB so the test_api event actually returns data.
+      _packet =
+        packet_fixture(%{
+          sender: "K5ABC-9",
+          base_callsign: "K5ABC",
+          ssid: "9",
+          received_at: DateTime.utc_now(),
+          lat: Decimal.new("33.0"),
+          lon: Decimal.new("-96.5"),
+          has_position: true,
+          comment: "API test packet",
+          temperature: 72.5,
+          humidity: 50
+        })
+
+      {:ok, lv, _html} = live(conn, ~p"/api", on_error: :warn)
+
+      lv
+      |> element("#test_callsign")
+      |> render_change(%{"callsign" => "K5ABC-9"})
+
+      lv
+      |> form("form[phx-submit=\"test_api\"]", %{"callsign" => "K5ABC-9"})
+      |> render_submit()
+
+      :ok = Process.sleep(150)
+      rendered = render(lv)
+      assert rendered =~ "K5ABC"
+      assert rendered =~ "data"
+    end
   end
 end