diff --git a/docs/sep.md b/docs/sep.md
index a9cebef..689fcfa 100644
--- a/docs/sep.md
+++ b/docs/sep.md
@@ -201,7 +201,7 @@ interface Interceptor {
   /**
    * Failure routing policy (default: false - fail-closed)
    *
-   * Enforce mode:
+   * Active mode:
    * - false (fail-closed): If the interceptor crashes or times out, block the message
    * - true (fail-open): If the interceptor fails, allow the message to proceed
    *
diff --git a/go/sdk/README.md b/go/sdk/README.md
index 2d59399..b16d9e4 100644
--- a/go/sdk/README.md
+++ b/go/sdk/README.md
@@ -22,7 +22,7 @@ ext.AddInterceptor(&interceptors.Validator{
             Events: []string{interceptors.EventToolsCall},
             Phase:  interceptors.PhaseRequest,
         }},
-        Mode: interceptors.ModeEnforce,
+        Mode: interceptors.ModeActive,
     },
     Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
         raw := inv.Payload.(json.RawMessage)
diff --git a/go/sdk/doc/DESIGN.md b/go/sdk/doc/DESIGN.md
index b48a52a..a93f66f 100644
--- a/go/sdk/doc/DESIGN.md
+++ b/go/sdk/doc/DESIGN.md
@@ -174,7 +174,7 @@ Response-phase validators see the post-mutation payload.
 
 ### Validator execution
 - All matching validators run in parallel (goroutines).
-- A validator returning `Valid: false` with `Severity: "error"` in enforced
+- A validator returning `Valid: false` with `Severity: "error"` in active
   mode aborts the chain.
 - `FailOpen: true` validators log errors and record an `InvokeResult`
   for observability, but don't abort.
diff --git a/go/sdk/examples/mutator/main.go b/go/sdk/examples/mutator/main.go
index ac4685d..1d72c2a 100644
--- a/go/sdk/examples/mutator/main.go
+++ b/go/sdk/examples/mutator/main.go
@@ -41,7 +41,7 @@ func main() {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseResponse,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.MutationResult, error) {
 			raw, ok := inv.Payload.(json.RawMessage)
diff --git a/go/sdk/examples/validator/main.go b/go/sdk/examples/validator/main.go
index 38436ed..d69705a 100644
--- a/go/sdk/examples/validator/main.go
+++ b/go/sdk/examples/validator/main.go
@@ -41,7 +41,7 @@ func main() {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			raw, ok := inv.Payload.(json.RawMessage)
diff --git a/go/sdk/interceptors/chain/chain_test.go b/go/sdk/interceptors/chain/chain_test.go
index 2c59385..f7fb8f6 100644
--- a/go/sdk/interceptors/chain/chain_test.go
+++ b/go/sdk/interceptors/chain/chain_test.go
@@ -155,7 +155,7 @@ func TestChain_ExecutionHandler(t *testing.T) {
 		wantNoPayload bool
 	}{
 		{
-			name: "audit-to-enforce validator override aborts chain",
+			name: "audit-to-active validator override aborts chain",
 			interceptor: &interceptors.Validator{
 				Metadata: interceptors.Metadata{
 					Name:  "v",
@@ -169,18 +169,18 @@ func TestChain_ExecutionHandler(t *testing.T) {
 					}, nil
 				},
 			},
-			directive:   &chain.Directive{Mode: modePtr(interceptors.ModeEnforce)},
+			directive:   &chain.Directive{Mode: modePtr(interceptors.ModeActive)},
 			phase:       interceptors.PhaseRequest,
 			wantStatus:  chain.ChainValidationFailed,
 			wantAborted: true,
 		},
 		{
-			name: "enforce-to-audit validator override does not abort",
+			name: "active-to-audit validator override does not abort",
 			interceptor: &interceptors.Validator{
 				Metadata: interceptors.Metadata{
 					Name:  "v",
 					Hooks: []interceptors.Hook{{Events: []string{"test/event"}, Phase: interceptors.PhaseRequest}},
-					Mode:  interceptors.ModeEnforce,
+					Mode:  interceptors.ModeActive,
 				},
 				Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 					return &interceptors.ValidationResult{
@@ -199,7 +199,7 @@ func TestChain_ExecutionHandler(t *testing.T) {
 				Metadata: interceptors.Metadata{
 					Name:  "m",
 					Hooks: []interceptors.Hook{{Events: []string{"test/event"}, Phase: interceptors.PhaseResponse}},
-					Mode:  interceptors.ModeEnforce,
+					Mode:  interceptors.ModeActive,
 				},
 				Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.MutationResult, error) {
 					modified, _ := json.Marshal(map[string]any{"value": "mutated"})
@@ -217,7 +217,7 @@ func TestChain_ExecutionHandler(t *testing.T) {
 				Metadata: interceptors.Metadata{
 					Name:  "v",
 					Hooks: []interceptors.Hook{{Events: []string{"test/event"}, Phase: interceptors.PhaseRequest}},
-					Mode:  interceptors.ModeEnforce,
+					Mode:  interceptors.ModeActive,
 				},
 				Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 					return &interceptors.ValidationResult{
@@ -275,7 +275,7 @@ func TestChain_ExecutionHandler_ShortCircuit(t *testing.T) {
 		Metadata: interceptors.Metadata{
 			Name:  "v",
 			Hooks: []interceptors.Hook{{Events: []string{"test/event"}, Phase: interceptors.PhaseRequest}},
-			Mode:  interceptors.ModeEnforce,
+			Mode:  interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			invoked = true
@@ -320,7 +320,7 @@ func TestChain_FailOpenRecordsExecutionResult(t *testing.T) {
 					Events: []string{"test/event"},
 					Phase:  interceptors.PhaseRequest,
 				}},
-				Mode:     interceptors.ModeEnforce,
+				Mode:     interceptors.ModeActive,
 				FailOpen: true,
 			},
 			Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
@@ -334,7 +334,7 @@ func TestChain_FailOpenRecordsExecutionResult(t *testing.T) {
 					Events: []string{"test/event"},
 					Phase:  interceptors.PhaseRequest,
 				}},
-				Mode: interceptors.ModeEnforce,
+				Mode: interceptors.ModeActive,
 			},
 			Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 				return &interceptors.ValidationResult{Valid: true}, nil
@@ -368,7 +368,7 @@ func TestChain_FailOpenRecordsExecutionResult(t *testing.T) {
 					Events: []string{"test/event"},
 					Phase:  interceptors.PhaseResponse,
 				}},
-				Mode:         interceptors.ModeEnforce,
+				Mode:         interceptors.ModeActive,
 				FailOpen:     true,
 				PriorityHint: interceptors.NewPriority(10),
 			},
@@ -383,7 +383,7 @@ func TestChain_FailOpenRecordsExecutionResult(t *testing.T) {
 					Events: []string{"test/event"},
 					Phase:  interceptors.PhaseResponse,
 				}},
-				Mode:         interceptors.ModeEnforce,
+				Mode:         interceptors.ModeActive,
 				PriorityHint: interceptors.NewPriority(20),
 			},
 			Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.MutationResult, error) {
@@ -468,7 +468,7 @@ func TestChain_AuditModeErrorsDoNotAbort(t *testing.T) {
 					Events: []string{"test/event"},
 					Phase:  interceptors.PhaseResponse,
 				}},
-				Mode:         interceptors.ModeEnforce,
+				Mode:         interceptors.ModeActive,
 				PriorityHint: interceptors.NewPriority(20),
 			},
 			Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.MutationResult, error) {
diff --git a/go/sdk/interceptors/doc.go b/go/sdk/interceptors/doc.go
index f2dea71..c3e0ed7 100644
--- a/go/sdk/interceptors/doc.go
+++ b/go/sdk/interceptors/doc.go
@@ -35,7 +35,7 @@
 //
 // A [Validator] inspects the payload and decides whether the request
 // or response should proceed. All validators for a given event run
-// in parallel. If any validator in enforced mode ([ModeEnforce])
+// in parallel. If any validator in active mode ([ModeActive])
 // returns an error-severity message, the chain aborts before any
 // mutators run. Only error-severity messages cause an abort; warn
 // and info findings are recorded in the chain execution result but
@@ -51,7 +51,7 @@
 //	            Events: []string{"tools/call"},
 //	            Phase:  interceptors.PhaseRequest,
 //	        }},
-//	        Mode: interceptors.ModeEnforce,
+//	        Mode: interceptors.ModeActive,
 //	    },
 //	    Handler: func(ctx context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 //	        raw := inv.Payload.(json.RawMessage)
@@ -79,7 +79,7 @@
 //	            Events: []string{"tools/call"},
 //	            Phase:  interceptors.PhaseResponse,
 //	        }},
-//	        Mode: interceptors.ModeEnforce,
+//	        Mode: interceptors.ModeActive,
 //	    },
 //	    Handler: func(ctx context.Context, inv *interceptors.Invocation) (*interceptors.MutationResult, error) {
 //	        raw := inv.Payload.(json.RawMessage)
@@ -112,7 +112,7 @@
 // successful results, and a FailOpen flag that controls what happens
 // when the handler returns a Go error. These are orthogonal:
 //
-//   - [ModeEnforce]: fully enforced — validation failures block,
+//   - [ModeActive]: fully active — validation failures block,
 //     mutations are applied.
 //   - [ModeAudit]: the handler runs and results are recorded, but
 //     validation findings do not block and mutated payloads are
@@ -138,15 +138,15 @@
 //
 // Behavior matrix for validators:
 //
-//	Mode=Enforce,  FailOpen=false → error aborts, Valid=false+SeverityError aborts
-//	Mode=Enforce,  FailOpen=true  → error continues, Valid=false+SeverityError aborts
+//	Mode=Active,  FailOpen=false → error aborts, Valid=false+SeverityError aborts
+//	Mode=Active,  FailOpen=true  → error continues, Valid=false+SeverityError aborts
 //	Mode=Audit, FailOpen=false → error aborts, findings recorded only
 //	Mode=Audit, FailOpen=true  → error continues, findings recorded only
 //
 // Behavior matrix for mutators:
 //
-//	Mode=Enforce,  FailOpen=false → error aborts, mutations applied
-//	Mode=Enforce,  FailOpen=true  → error continues, mutations applied
+//	Mode=Active,  FailOpen=false → error aborts, mutations applied
+//	Mode=Active,  FailOpen=true  → error continues, mutations applied
 //	Mode=Audit, FailOpen=false → error aborts, mutations not propagated
 //	Mode=Audit, FailOpen=true  → error continues, mutations not propagated
 package interceptors
diff --git a/go/sdk/interceptors/extension/rpc_test.go b/go/sdk/interceptors/extension/rpc_test.go
index 8721f5e..ab00e7d 100644
--- a/go/sdk/interceptors/extension/rpc_test.go
+++ b/go/sdk/interceptors/extension/rpc_test.go
@@ -48,7 +48,7 @@ func TestListWithEventFilter(t *testing.T) {
 				Events: []string{interceptors.EventPromptsGet},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			return &interceptors.ValidationResult{Valid: true}, nil
@@ -122,7 +122,7 @@ func TestInvokeValidatorRejects(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			return &interceptors.ValidationResult{
@@ -166,7 +166,7 @@ func TestInvokeMutator(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.MutationResult, error) {
 			raw, ok := inv.Payload.(json.RawMessage)
@@ -244,7 +244,7 @@ func TestInvokeTimeout(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(ctx context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			select {
diff --git a/go/sdk/interceptors/extension/server_integration_test.go b/go/sdk/interceptors/extension/server_integration_test.go
index 732d1cd..d4c380f 100644
--- a/go/sdk/interceptors/extension/server_integration_test.go
+++ b/go/sdk/interceptors/extension/server_integration_test.go
@@ -35,7 +35,7 @@ func TestServer_ValidatorAllowsTool(t *testing.T) {
 
 func TestServer_MutatorModifiesResponse(t *testing.T) {
 	t.Parallel()
-	cs := setup(t, prefixMutator("prefix", "[mutated]", interceptors.PhaseResponse, 0, interceptors.ModeEnforce))
+	cs := setup(t, prefixMutator("prefix", "[mutated]", interceptors.PhaseResponse, 0, interceptors.ModeActive))
 
 	result, err := callEcho(t, cs)
 	require.NoError(t, err)
@@ -50,11 +50,11 @@ func TestServer_ChainedMutatorsWithAuditMode(t *testing.T) {
 	//
 	//   [M5] [M4] [M2] [M1] echo: ...
 	cs := setup(t,
-		prefixMutator("m1", "[M1]", interceptors.PhaseResponse, 10, interceptors.ModeEnforce),
-		prefixMutator("m2", "[M2]", interceptors.PhaseResponse, 20, interceptors.ModeEnforce),
+		prefixMutator("m1", "[M1]", interceptors.PhaseResponse, 10, interceptors.ModeActive),
+		prefixMutator("m2", "[M2]", interceptors.PhaseResponse, 20, interceptors.ModeActive),
 		prefixMutator("m3-audit", "[AUDIT]", interceptors.PhaseResponse, 30, interceptors.ModeAudit),
-		prefixMutator("m4", "[M4]", interceptors.PhaseResponse, 40, interceptors.ModeEnforce),
-		prefixMutator("m5", "[M5]", interceptors.PhaseResponse, 50, interceptors.ModeEnforce),
+		prefixMutator("m4", "[M4]", interceptors.PhaseResponse, 40, interceptors.ModeActive),
+		prefixMutator("m5", "[M5]", interceptors.PhaseResponse, 50, interceptors.ModeActive),
 	)
 
 	result, err := callEcho(t, cs)
@@ -70,9 +70,9 @@ func TestServer_MutatorFailureAbortsChain(t *testing.T) {
 	// 3 response mutators. Mutator 2 (priority 20) returns an error
 	// and is fail-closed. The chain aborts; client receives an error.
 	cs := setup(t,
-		prefixMutator("m1", "[M1]", interceptors.PhaseResponse, 10, interceptors.ModeEnforce),
+		prefixMutator("m1", "[M1]", interceptors.PhaseResponse, 10, interceptors.ModeActive),
 		failMutator("m2-fail", interceptors.PhaseResponse, 20),
-		prefixMutator("m3", "[M3]", interceptors.PhaseResponse, 30, interceptors.ModeEnforce),
+		prefixMutator("m3", "[M3]", interceptors.PhaseResponse, 30, interceptors.ModeActive),
 	)
 
 	_, err := callEcho(t, cs)
@@ -90,7 +90,7 @@ func TestServer_ValidatorWarnDoesNotBlock(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			return &interceptors.ValidationResult{
@@ -121,7 +121,7 @@ func TestServer_ValidationFailurePreventsM(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.MutationResult, error) {
 			mutatorRan.Store(true)
@@ -145,7 +145,7 @@ func TestServer_ValidatorTimeoutAbortsChain(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(ctx context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			select {
@@ -176,7 +176,7 @@ func TestServer_MutatorTimeoutAbortsChain(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseResponse,
 			}},
-			Mode:         interceptors.ModeEnforce,
+			Mode:         interceptors.ModeActive,
 			PriorityHint: interceptors.NewPriority(20),
 		},
 		Handler: func(ctx context.Context, _ *interceptors.Invocation) (*interceptors.MutationResult, error) {
@@ -190,9 +190,9 @@ func TestServer_MutatorTimeoutAbortsChain(t *testing.T) {
 	}
 
 	cs := setup(t,
-		prefixMutator("m1", "[M1]", interceptors.PhaseResponse, 10, interceptors.ModeEnforce),
+		prefixMutator("m1", "[M1]", interceptors.PhaseResponse, 10, interceptors.ModeActive),
 		slowMutator,
-		prefixMutator("m3", "[M3]", interceptors.PhaseResponse, 30, interceptors.ModeEnforce),
+		prefixMutator("m3", "[M3]", interceptors.PhaseResponse, 30, interceptors.ModeActive),
 	)
 
 	// Per-invocation timeout: context expires before the 100ms handler completes.
@@ -212,7 +212,7 @@ func TestServer_MutatorFailOpenContinuesChain(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseResponse,
 			}},
-			Mode:         interceptors.ModeEnforce,
+			Mode:         interceptors.ModeActive,
 			FailOpen:     true,
 			PriorityHint: interceptors.NewPriority(20),
 		},
@@ -222,9 +222,9 @@ func TestServer_MutatorFailOpenContinuesChain(t *testing.T) {
 	}
 
 	cs := setup(t,
-		prefixMutator("m1", "[M1]", interceptors.PhaseResponse, 10, interceptors.ModeEnforce),
+		prefixMutator("m1", "[M1]", interceptors.PhaseResponse, 10, interceptors.ModeActive),
 		failOpenMutator,
-		prefixMutator("m3", "[M3]", interceptors.PhaseResponse, 30, interceptors.ModeEnforce),
+		prefixMutator("m3", "[M3]", interceptors.PhaseResponse, 30, interceptors.ModeActive),
 	)
 
 	result, err := callEcho(t, cs)
@@ -252,7 +252,7 @@ func TestServer_ResponseMutatorSeesMutatedParams(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.MutationResult, error) {
 			raw, ok := inv.Payload.(json.RawMessage)
@@ -313,7 +313,7 @@ func TestServer_CombinedValidatorsAndMutators(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			reqValCount.Add(1)
@@ -347,7 +347,7 @@ func TestServer_CombinedValidatorsAndMutators(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			reqValCount.Add(1)
@@ -385,7 +385,7 @@ func TestServer_CombinedValidatorsAndMutators(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			reqValCount.Add(1)
@@ -409,7 +409,7 @@ func TestServer_CombinedValidatorsAndMutators(t *testing.T) {
 					Events: []string{interceptors.EventToolsCall},
 					Phase:  interceptors.PhaseRequest,
 				}},
-				Mode:         interceptors.ModeEnforce,
+				Mode:         interceptors.ModeActive,
 				PriorityHint: interceptors.NewPriority(priority),
 			},
 			Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.MutationResult, error) {
@@ -458,7 +458,7 @@ func TestServer_CombinedValidatorsAndMutators(t *testing.T) {
 					Events: []string{interceptors.EventToolsCall},
 					Phase:  interceptors.PhaseResponse,
 				}},
-				Mode:         interceptors.ModeEnforce,
+				Mode:         interceptors.ModeActive,
 				PriorityHint: interceptors.NewPriority(priority),
 			},
 			Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.MutationResult, error) {
@@ -500,7 +500,7 @@ func TestServer_CombinedValidatorsAndMutators(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseResponse,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			respValCount.Add(1)
@@ -534,7 +534,7 @@ func TestServer_CombinedValidatorsAndMutators(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseResponse,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			respValCount.Add(1)
@@ -570,7 +570,7 @@ func TestServer_CombinedValidatorsAndMutators(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseResponse,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			respValCount.Add(1)
diff --git a/go/sdk/interceptors/extension/testharness_test.go b/go/sdk/interceptors/extension/testharness_test.go
index 19aa582..97b37dd 100644
--- a/go/sdk/interceptors/extension/testharness_test.go
+++ b/go/sdk/interceptors/extension/testharness_test.go
@@ -231,7 +231,7 @@ func failMutator(name string, phase interceptors.InterceptionPhase, priority int
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  phase,
 			}},
-			Mode:         interceptors.ModeEnforce,
+			Mode:         interceptors.ModeActive,
 			PriorityHint: interceptors.NewPriority(priority),
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.MutationResult, error) {
@@ -249,7 +249,7 @@ func blockToolValidator(toolName string) *interceptors.Validator {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			raw, ok := inv.Payload.(json.RawMessage)
@@ -284,7 +284,7 @@ func allowAllValidator(name string) *interceptors.Validator {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			return &interceptors.ValidationResult{Valid: true}, nil
diff --git a/go/sdk/interceptors/integrations/gomiddleware/middleware_test.go b/go/sdk/interceptors/integrations/gomiddleware/middleware_test.go
index 457fd32..65a2e76 100644
--- a/go/sdk/interceptors/integrations/gomiddleware/middleware_test.go
+++ b/go/sdk/interceptors/integrations/gomiddleware/middleware_test.go
@@ -85,7 +85,7 @@ func TestMiddlewareBlocksOnValidationError(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			raw, ok := inv.Payload.(json.RawMessage)
@@ -129,7 +129,7 @@ func TestMiddlewarePassesOnSuccess(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, _ *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			return &interceptors.ValidationResult{Valid: true}, nil
@@ -156,7 +156,7 @@ func TestMiddlewareMutatesPayload(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseResponse,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.MutationResult, error) {
 			raw, ok := inv.Payload.(json.RawMessage)
@@ -234,7 +234,7 @@ func TestMiddlewareWithContextProvider(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
 			if inv.Context == nil || inv.Context.Principal == nil || inv.Context.Principal.ID != "test-user" {
@@ -316,7 +316,7 @@ func TestMiddlewareRequestMutatorModifiesArgs(t *testing.T) {
 				Events: []string{interceptors.EventToolsCall},
 				Phase:  interceptors.PhaseRequest,
 			}},
-			Mode: interceptors.ModeEnforce,
+			Mode: interceptors.ModeActive,
 		},
 		Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.MutationResult, error) {
 			raw, ok := inv.Payload.(json.RawMessage)
diff --git a/go/sdk/interceptors/interceptor.go b/go/sdk/interceptors/interceptor.go
index ffdee99..1d3f33b 100644
--- a/go/sdk/interceptors/interceptor.go
+++ b/go/sdk/interceptors/interceptor.go
@@ -33,8 +33,8 @@ type InterceptionEvent = string
 type Mode string
 
 const (
-	ModeEnforce Mode = "enforce" // Enforced: validation failures block, mutations apply
-	ModeAudit   Mode = "audit"   // Audit: log results but don't block or apply mutations
+	ModeActive Mode = "active" // Active: validation failures block, mutations apply
+	ModeAudit  Mode = "audit"  // Audit: log results but don't block or apply mutations
 )
 
 // InterceptorType identifies the category of an interceptor.