diff --git a/config_test.go b/config_test.go
new file mode 100644
index 0000000..63fe03e
--- /dev/null
+++ b/config_test.go
@@ -0,0 +1,52 @@
+package corbado
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewConfig_Success(t *testing.T) {
+	projectID := "pro-12345678"
+	secret := "mysupersecret"
+
+	cfg, err := NewConfig(projectID, secret)
+	require.NoError(t, err)
+
+	assert.Equal(t, projectID, cfg.ProjectID)
+	assert.Equal(t, secret, cfg.APISecret)
+	assert.Equal(t, fmt.Sprintf(configDefaultFrontendAPI, projectID), cfg.FrontendAPI)
+	assert.Equal(t, configDefaultBackendAPI, cfg.BackendAPI)
+	assert.Equal(t, configDefaultShortSessionCookieName, cfg.ShortSessionCookieName)
+	assert.Equal(t, configDefaultCacheMaxAge, cfg.CacheMaxAge)
+}
+
+func TestNewConfig_Failure(t *testing.T) {
+	tests := []struct {
+		name      string
+		projectID string
+		secret    string
+	}{
+		{
+			name: "empty projectID and secret",
+		},
+		{
+			name:   "empty projectID",
+			secret: "secret",
+		},
+		{
+			name:      "empty secret",
+			projectID: "pro-12345678",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			cfg, err := NewConfig(test.projectID, test.secret)
+			assert.Nil(t, cfg)
+			assert.ErrorContains(t, err, "given value '' is too short")
+		})
+	}
+}
diff --git a/go.mod b/go.mod
index 4548957..6b0037f 100644
--- a/go.mod
+++ b/go.mod
@@ -8,9 +8,13 @@ require (
 	github.com/golang-jwt/jwt/v4 v4.4.2
 	github.com/oapi-codegen/runtime v1.0.0
 	github.com/pkg/errors v0.9.1
+	github.com/stretchr/testify v1.8.4
 )
 
 require (
 	github.com/apapsch/go-jsonmerge/v2 v2.0.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/uuid v1.3.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/go.sum b/go.sum
index 5d46542..46eb071 100644
--- a/go.sum
+++ b/go.sum
@@ -6,6 +6,7 @@ github.com/apapsch/go-jsonmerge/v2 v2.0.0/go.mod h1:lvDnEdqiQrp0O42VQGgmlKpxL1AP
 github.com/bmatcuk/doublestar v1.1.1/go.mod h1:UD6OnuiIn0yFxxA2le/rnRU1G4RaI4UvFv1sNto9p6w=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/deepmap/oapi-codegen v1.16.2 h1:xGHx0dNqYfy9gE8a7AVgVM8Sd5oF9SEgePzP+UPAUXI=
 github.com/deepmap/oapi-codegen v1.16.2/go.mod h1:rdYoEA2GE+riuZ91DvpmBX9hJbQpuY9wchXpfQ3n+ho=
 github.com/golang-jwt/jwt/v4 v4.4.2 h1:rcc4lwaZgFMCZ5jxF9ABolDcIHdBytAFgqFPbSJQAYs=
@@ -23,4 +24,8 @@ github.com/spkg/bom v0.0.0-20160624110644-59b7046e48ad/go.mod h1:qLr4V1qq6nMqFKk
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=