diff --git a/pkg/modules/humaecho5/humaecho5_test.go b/pkg/modules/humaecho5/humaecho5_test.go
new file mode 100644
index 000000000..6b9bdf753
--- /dev/null
+++ b/pkg/modules/humaecho5/humaecho5_test.go
@@ -0,0 +1,71 @@
+package humaecho5_test
+
+import (
+	"context"
+	"encoding/json"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"code.vikunja.io/api/pkg/modules/humaecho5"
+	"github.com/danielgtaylor/huma/v2"
+	"github.com/labstack/echo/v5"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestAdapterRoundtrip proves that a Huma operation registered against the
+// v5 adapter is served by Echo and that the echo.Context is retrievable
+// from the handler's context.Context via EchoContextKey.
+func TestAdapterRoundtrip(t *testing.T) {
+	e := echo.New()
+	api := humaecho5.New(e, huma.DefaultConfig("spike", "0.0.1"))
+
+	type pingInput struct {
+		Name string `path:"name"`
+	}
+	type pingOutput struct {
+		Body struct {
+			Echo string `json:"echo"`
+			HasEchoCtx bool `json:"has_echo_ctx"`
+		}
+	}
+
+	huma.Register(api, huma.Operation{
+		OperationID: "ping",
+		Method:      "GET",
+		Path:        "/ping/{name}",
+	}, func(ctx context.Context, in *pingInput) (*pingOutput, error) {
+		_, ok := ctx.Value(humaecho5.EchoContextKey).(*echo.Context)
+		out := &pingOutput{}
+		out.Body.Echo = in.Name
+		out.Body.HasEchoCtx = ok
+		return out, nil
+	})
+
+	req := httptest.NewRequest("GET", "/ping/world", nil)
+	rec := httptest.NewRecorder()
+	e.ServeHTTP(rec, req)
+
+	require.Equal(t, 200, rec.Code, "body: %s", rec.Body.String())
+	var got struct {
+		Echo       string `json:"echo"`
+		HasEchoCtx bool   `json:"has_echo_ctx"`
+	}
+	require.NoError(t, json.NewDecoder(rec.Body).Decode(&got))
+	assert.Equal(t, "world", got.Echo)
+	assert.True(t, got.HasEchoCtx, "echo.Context not stashed on request ctx")
+}
+
+// TestOpenAPISpecServed proves Huma serves the OAS 3.1 spec document
+// on its configured URL.
+func TestOpenAPISpecServed(t *testing.T) {
+	e := echo.New()
+	_ = humaecho5.New(e, huma.DefaultConfig("spike", "0.0.1"))
+	req := httptest.NewRequest("GET", "/openapi.json", nil)
+	rec := httptest.NewRecorder()
+	e.ServeHTTP(rec, req)
+	require.Equal(t, 200, rec.Code)
+	assert.True(t, strings.Contains(rec.Body.String(), `"openapi":"3.1`),
+		"expected OAS 3.1 header, got %s", rec.Body.String())
+}