feat: enable to ignore cost weights on implementing types

router-tests/go.mod

@@ -31,7 +31,7 @@ require (
 	github.com/wundergraph/cosmo/router v0.0.0-20260330183556-dc4388d100a4
 	github.com/wundergraph/cosmo/router-plugin v0.0.0-20250808194725-de123ba1c65e
 	github.com/wundergraph/cosmo/speedtrap v0.0.0-00010101000000-000000000000
-	github.com/wundergraph/graphql-go-tools/v2 v2.4.6
+	github.com/wundergraph/graphql-go-tools/v2 v2.5.0
 	go.opentelemetry.io/otel v1.44.0
 	go.opentelemetry.io/otel/sdk v1.44.0
 	go.opentelemetry.io/otel/sdk/metric v1.44.0

router-tests/go.sum

@@ -381,8 +381,8 @@ github.com/wundergraph/astjson v1.1.0 h1:xORDosrZ87zQFJwNGe/HIHXqzpdHOFmqWgykCLV
 github.com/wundergraph/astjson v1.1.0/go.mod h1:h12D/dxxnedtLzsKyBLK7/Oe4TAoGpRVC9nDpDrZSWw=
 github.com/wundergraph/go-arena v1.3.0 h1:n0ng5a1vbd8YGq1u3rMr0vPU5f6AZ1BXIiUhL1UIok8=
 github.com/wundergraph/go-arena v1.3.0/go.mod h1:ROOysEHWJjLQ8FSfNxZCziagb7Qw2nXY3/vgKRh7eWw=
-github.com/wundergraph/graphql-go-tools/v2 v2.4.6 h1:MqUDusuiOGlO0Oa8etTdcVA2ySmY0XehTDq/dILelEw=
-github.com/wundergraph/graphql-go-tools/v2 v2.4.6/go.mod h1:rGG9m74sUyucfvSZ83Mjuq/6qRJetl1CVP872f/dCok=
+github.com/wundergraph/graphql-go-tools/v2 v2.5.0 h1:Id21OFacHv9gaictZR+dPDYWNFF0WQXbAIE4Y81Vujo=
+github.com/wundergraph/graphql-go-tools/v2 v2.5.0/go.mod h1:rGG9m74sUyucfvSZ83Mjuq/6qRJetl1CVP872f/dCok=
 github.com/xrash/smetrics v0.0.0-20250705151800-55b8f293f342 h1:FnBeRrxr7OU4VvAzt5X7s6266i6cSVkkFPS0TuXWbIg=
 github.com/xrash/smetrics v0.0.0-20250705151800-55b8f293f342/go.mod h1:Ohn+xnUBiLI6FVj/9LpzZWtj1/D6lUovWYBkxHVV3aM=
 github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=

router-tests/security/costs_test.go

@@ -221,10 +221,10 @@ func TestOperationCost(t *testing.T) {
 				require.Contains(t, res.Body, `"data":`)
 				require.NotContains(t, res.Body, `"errors":`)
 
-				// 50 * (employees(1) + id(0) + 1 * (role(1) + 3 * departments(1) + 5 * title(1)))
-				require.Equal(t, "500", res.Response.Header.Get(core.CostEstimatedHeader))
-				// 10 * (employees(1) + id(0) + 1 * (role(1) + 1.2 * departments(1) + 1.4 * title(1)))
-				require.Equal(t, "46", res.Response.Header.Get(core.CostActualHeader))
+				// 50 * (employees(1) + id(0) + 1 * (role(1) + 3 * departments(1) + 5 * title(0)))
+				require.Equal(t, "250", res.Response.Header.Get(core.CostEstimatedHeader))
+				// 10 * (employees(1) + id(0) + 1 * (role(1) + 1.2 * departments(1) + 1.4 * title(0)))
+				require.Equal(t, "32", res.Response.Header.Get(core.CostActualHeader))
 			})
 		})
 
@@ -384,6 +384,37 @@ func TestOperationCost(t *testing.T) {
 			})
 		})
 
+		t.Run("ignore_implementing_type_weights excludes implementing-type weights on abstract fields", func(t *testing.T) {
+			t.Parallel()
+			// The RoleType interface field "employees" has no weight of its own.
+			// With the flag on, that implementing-type weight is skipped (Apollo behavior).
+			testenv.Run(t, &testenv.Config{
+				ModifySecurityConfiguration: func(securityConfiguration *config.SecurityConfiguration) {
+					securityConfiguration.CostControl = &config.CostControl{
+						Enabled:                       true,
+						Mode:                          config.CostControlModeMeasure,
+						MaxEstimatedLimit:             10000,
+						EstimatedListSize:             10,
+						ExposeHeaders:                 true,
+						IgnoreImplementingTypeWeights: true,
+					}
+				},
+			}, func(t *testing.T, xEnv *testenv.Environment) {
+				res := xEnv.MakeGraphQLRequestOK(testenv.GraphQLRequest{
+					Query: `{ employee(id:1) { role { employees { id } } } }`,
+				})
+				require.Contains(t, res.Body, `"data":`)
+				require.NotContains(t, res.Body, `"errors":`)
+
+				// "@expensiveOp(coefficient: Int = 2 @cost(weight: 22))" should not be used!
+
+				// employee.arg(2) + 1 * (employee(5) + 1 * (role(1) + 10 * employees(1)))
+				require.Equal(t, "18", res.Response.Header.Get(core.CostEstimatedHeader))
+				// employee.arg(2) + 1 * (employee(5) + 1 * (role(1) + 7 * employees(1)))
+				require.Equal(t, "15", res.Response.Header.Get(core.CostActualHeader))
+			})
+		})
+
 		t.Run("slicingArguments controls list size estimation", func(t *testing.T) {
 			t.Parallel()
 			testenv.Run(t, &testenv.Config{

router/core/executor.go

@@ -260,6 +260,7 @@ func (b *ExecutorConfigurationBuilder) buildPlannerConfiguration(ctx context.Con
 	if routerEngineCfg.CostControl != nil && routerEngineCfg.CostControl.Enabled {
 		planConfig.ComputeCosts = true
 		planConfig.StaticCostDefaultListSize = routerEngineCfg.CostControl.EstimatedListSize
+		planConfig.IgnoreImplementingTypeWeights = routerEngineCfg.CostControl.IgnoreImplementingTypeWeights
 	}
 
 	return planConfig, providers, nil

router/go.mod

@@ -31,7 +31,7 @@ require (
 	github.com/tidwall/gjson v1.18.0
 	github.com/tidwall/sjson v1.2.5
 	github.com/twmb/franz-go v1.16.1
-	github.com/wundergraph/graphql-go-tools/v2 v2.4.6
+	github.com/wundergraph/graphql-go-tools/v2 v2.5.0
 	// Do not upgrade, it renames attributes we rely on
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.68.0
 	go.opentelemetry.io/contrib/propagators/b3 v1.44.0

router/go.sum

@@ -333,8 +333,8 @@ github.com/wundergraph/astjson v1.1.0 h1:xORDosrZ87zQFJwNGe/HIHXqzpdHOFmqWgykCLV
 github.com/wundergraph/astjson v1.1.0/go.mod h1:h12D/dxxnedtLzsKyBLK7/Oe4TAoGpRVC9nDpDrZSWw=
 github.com/wundergraph/go-arena v1.3.0 h1:n0ng5a1vbd8YGq1u3rMr0vPU5f6AZ1BXIiUhL1UIok8=
 github.com/wundergraph/go-arena v1.3.0/go.mod h1:ROOysEHWJjLQ8FSfNxZCziagb7Qw2nXY3/vgKRh7eWw=
-github.com/wundergraph/graphql-go-tools/v2 v2.4.6 h1:MqUDusuiOGlO0Oa8etTdcVA2ySmY0XehTDq/dILelEw=
-github.com/wundergraph/graphql-go-tools/v2 v2.4.6/go.mod h1:rGG9m74sUyucfvSZ83Mjuq/6qRJetl1CVP872f/dCok=
+github.com/wundergraph/graphql-go-tools/v2 v2.5.0 h1:Id21OFacHv9gaictZR+dPDYWNFF0WQXbAIE4Y81Vujo=
+github.com/wundergraph/graphql-go-tools/v2 v2.5.0/go.mod h1:rGG9m74sUyucfvSZ83Mjuq/6qRJetl1CVP872f/dCok=
 github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=
 github.com/yosida95/uritemplate/v3 v3.0.2/go.mod h1:ILOh0sOhIJR3+L/8afwt/kE++YT040gmv5BQTMR2HP4=
 github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=

router/pkg/config/config.go

@@ -577,6 +577,11 @@ type CostControl struct {
 
 	// ExposeHeaders adds X-WG-Cost-* response headers.
 	ExposeHeaders bool `yaml:"expose_headers,omitempty" envDefault:"false" env:"EXPOSE_HEADERS"`
+
+	// IgnoreImplementingTypeWeights, when true, ignores @cost weights contributed by
+	// implementing types on abstract (interface/union) fields that have no weight of
+	// their own. Emulates Apollo's cost behavior.
+	IgnoreImplementingTypeWeights bool `yaml:"ignore_implementing_type_weights,omitempty" envDefault:"false" env:"IGNORE_IMPLEMENTING_TYPE_WEIGHTS"`
 }
 
 type ComplexityLimit struct {

router/pkg/config/config.schema.json

@@ -3531,6 +3531,11 @@
             "expose_headers": {
               "type": "boolean",
               "description": "Enable costs response headers for estimated and actuals operation costs."
+            },
+            "ignore_implementing_type_weights": {
+              "type": "boolean",
+              "default": false,
+              "description": "When enabled, ignores @cost weights from implementing types on abstract (interface/union) fields that have no weight of their own. Emulates Apollo's cost behavior."
             }
           }
         },

router/pkg/config/testdata/config_full.json

@@ -871,7 +871,8 @@
       "Mode": "enforce",
       "MaxEstimatedLimit": 1000,
       "EstimatedListSize": 10,
-      "ExposeHeaders": false
+      "ExposeHeaders": false,
+      "IgnoreImplementingTypeWeights": false
     },
     "DepthLimit": null,
     "ParserLimits": {