diff --git a/cmd/mcp/serve.go b/cmd/mcp/serve.go
index a5c79d1..266e54a 100644
--- a/cmd/mcp/serve.go
+++ b/cmd/mcp/serve.go
@@ -7,6 +7,8 @@ import (
 	"net/http"
 	"strings"
 
+	"seerr-cli/cmd/apiutil"
+
 	"github.com/mark3labs/mcp-go/server"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -75,6 +77,10 @@ func runServe(_ *cobra.Command, args []string) error {
 		return err
 	}
 
+	if err := ValidateServeConfig(); err != nil {
+		return err
+	}
+
 	if transport == "http" && authToken == "" && routeToken == "" && !noAuth {
 		return fmt.Errorf("HTTP transport requires --auth-token, --route-token, or --no-auth (insecure) to be set explicitly")
 	}
@@ -185,6 +191,16 @@ func runServe(_ *cobra.Command, args []string) error {
 	}
 }
 
+// ValidateServeConfig checks that the Seerr server URL is configured. It is
+// exported so that tests can verify the fail-fast behaviour without starting
+// the server.
+func ValidateServeConfig() error {
+	if apiutil.NormalizeServerURL(viper.GetString("seerr.server")) == "" {
+		return fmt.Errorf("seerr.server is not configured; set it with --server <url> or add seerr.server to ~/.seerr-cli.yaml")
+	}
+	return nil
+}
+
 // HealthCheckHandler responds to GET /health with a JSON status payload.
 // It is exported so that it can be tested directly from the tests package.
 func HealthCheckHandler(w http.ResponseWriter, r *http.Request) {
diff --git a/tests/mcp_serve_validation_test.go b/tests/mcp_serve_validation_test.go
new file mode 100644
index 0000000..fd41a47
--- /dev/null
+++ b/tests/mcp_serve_validation_test.go
@@ -0,0 +1,58 @@
+package tests
+
+import (
+	"testing"
+
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	cmdmcp "seerr-cli/cmd/mcp"
+)
+
+func TestMCPServeFailsFastWithoutSeerrServer(t *testing.T) {
+	original := viper.GetString("seerr.server")
+	t.Cleanup(func() { viper.Set("seerr.server", original) })
+
+	tests := []struct {
+		name        string
+		seerrServer string
+		wantErr     bool
+		errContains string
+	}{
+		{
+			name:        "missing server returns error",
+			seerrServer: "",
+			wantErr:     true,
+			errContains: "seerr.server",
+		},
+		{
+			name:        "only slashes returns error",
+			seerrServer: "///",
+			wantErr:     true,
+			errContains: "seerr.server",
+		},
+		{
+			name:        "valid server passes validation",
+			seerrServer: "http://localhost:5055",
+			wantErr:     false,
+		},
+		{
+			name:        "valid server with trailing slash passes validation",
+			seerrServer: "http://localhost:5055/",
+			wantErr:     false,
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			viper.Set("seerr.server", tc.seerrServer)
+			err := cmdmcp.ValidateServeConfig()
+			if tc.wantErr {
+				require.Error(t, err)
+				assert.Contains(t, err.Error(), tc.errContains)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}