diff --git a/centipede/BUILD b/centipede/BUILD
index 5bb99e3e..b276a259 100644
--- a/centipede/BUILD
+++ b/centipede/BUILD
@@ -931,8 +931,8 @@ cc_library(
         "@com_google_absl//absl/random",
         "@com_google_absl//absl/types:span",
         "@com_google_fuzztest//common:defs",
-        "@com_google_fuzztest//fuzztest:coverage",
         "@com_google_fuzztest//fuzztest:domain_core",
+        "@com_google_fuzztest//fuzztest:table_of_recent_compares",
     ],
 )
 
diff --git a/centipede/fuzztest_mutator.cc b/centipede/fuzztest_mutator.cc
index fc85d362..3ea290d5 100644
--- a/centipede/fuzztest_mutator.cc
+++ b/centipede/fuzztest_mutator.cc
@@ -29,7 +29,7 @@
 #include "./centipede/mutation_input.h"
 #include "./common/defs.h"
 #include "./fuzztest/domain_core.h"
-#include "./fuzztest/internal/coverage.h"
+#include "./fuzztest/internal/table_of_recent_compares.h"
 
 namespace centipede {
 
@@ -40,30 +40,25 @@ using MutatorDomainBase =
 
 }  // namespace
 
+struct FuzzTestMutator::MutationMetadata {
+  fuzztest::internal::TablesOfRecentCompares cmp_tables;
+};
+
 class FuzzTestMutator::MutatorDomain : public MutatorDomainBase {
  public:
   MutatorDomain()
       : MutatorDomainBase(fuzztest::VectorOf(fuzztest::Arbitrary<uint8_t>())) {
-    if (fuzztest::internal::GetExecutionCoverage() == nullptr) {
-      execution_coverage_ = std::make_unique<ExecutionCoverage>(
-          /*counter_map=*/absl::Span<uint8_t>{});
-      execution_coverage_->SetIsTracing(true);
-      fuzztest::internal::SetExecutionCoverage(execution_coverage_.get());
-    }
   }
 
   ~MutatorDomain() {
-    if (fuzztest::internal::GetExecutionCoverage() == execution_coverage_.get())
-      fuzztest::internal::SetExecutionCoverage(nullptr);
   }
-
- private:
-  using ExecutionCoverage = fuzztest::internal::ExecutionCoverage;
-  std::unique_ptr<ExecutionCoverage> execution_coverage_;
 };
 
 FuzzTestMutator::FuzzTestMutator(const Knobs &knobs, uint64_t seed)
-    : knobs_(knobs), prng_(seed), domain_(std::make_unique<MutatorDomain>()) {
+    : knobs_(knobs),
+      prng_(seed),
+      mutation_metadata_(std::make_unique<MutationMetadata>()),
+      domain_(std::make_unique<MutatorDomain>()) {
   domain_->WithMinSize(1).WithMaxSize(max_len_);
 }
 
@@ -123,23 +118,23 @@ void FuzzTestMutator::MutateMany(const std::vector<MutationInputRef>& inputs,
           inputs[absl::Uniform<size_t>(prng_, 0, inputs.size())].data;
       CrossOver(mutant, other_input);
     } else {
-      domain_->Mutate(mutant, prng_, /*only_shrink=*/false);
+      domain_->Mutate(mutant, prng_,
+                      {.cmp_tables = &mutation_metadata_->cmp_tables},
+                      /*only_shrink=*/false);
     }
     mutants.push_back(std::move(mutant));
   }
 }
 
 void FuzzTestMutator::SetMetadata(const ExecutionMetadata& metadata) {
-  metadata.ForEachCmpEntry([](ByteSpan a, ByteSpan b) {
+  metadata.ForEachCmpEntry([this](ByteSpan a, ByteSpan b) {
     size_t size = a.size();
     if (size < kMinCmpEntrySize) return;
     if (size > kMaxCmpEntrySize) return;
     // Use the memcmp table to avoid subtlety of the container domain mutation
     // with integer tables. E.g. it won't insert integer comparison data.
-    fuzztest::internal::GetExecutionCoverage()
-        ->GetTablesOfRecentCompares()
-        .GetMutable<0>()
-        .Insert(a.data(), b.data(), size);
+    mutation_metadata_->cmp_tables.GetMutable<0>().Insert(a.data(), b.data(),
+                                                          size);
   });
 }
 
diff --git a/centipede/fuzztest_mutator.h b/centipede/fuzztest_mutator.h
index 3afa48bb..b9c81618 100644
--- a/centipede/fuzztest_mutator.h
+++ b/centipede/fuzztest_mutator.h
@@ -54,6 +54,7 @@ class FuzzTestMutator {
   // TODO(xinhaoyuan): Support set_alignment().
 
  private:
+  class MutationMetadata;
   class MutatorDomain;
 
   // Propagates the execution `metadata` to the internal mutation dictionary.
@@ -72,6 +73,8 @@ class FuzzTestMutator {
   const Knobs &knobs_;
   Rng prng_;
   size_t max_len_ = 1000;
+
+  std::unique_ptr<MutationMetadata> mutation_metadata_;
   std::unique_ptr<MutatorDomain> domain_;
 };
 
diff --git a/domain_tests/BUILD b/domain_tests/BUILD
index 8b0dc9b7..2d882741 100644
--- a/domain_tests/BUILD
+++ b/domain_tests/BUILD
@@ -92,8 +92,8 @@ cc_test(
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/container:flat_hash_set",
         "@com_google_absl//absl/random",
-        "@com_google_fuzztest//fuzztest:coverage",
         "@com_google_fuzztest//fuzztest:domain_core",
+        "@com_google_fuzztest//fuzztest:table_of_recent_compares",
         "@com_google_fuzztest//fuzztest:type_support",
         "@com_google_googletest//:gtest_main",
     ],
@@ -111,6 +111,7 @@ cc_library(
         "@com_google_absl//absl/random:bit_gen_ref",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/strings",
+        "@com_google_fuzztest//fuzztest:domain_core",
         "@com_google_fuzztest//fuzztest:logging",
         "@com_google_fuzztest//fuzztest:meta",
         "@com_google_fuzztest//fuzztest:serialization",
diff --git a/domain_tests/CMakeLists.txt b/domain_tests/CMakeLists.txt
index 3ba1e94b..8900ccc4 100644
--- a/domain_tests/CMakeLists.txt
+++ b/domain_tests/CMakeLists.txt
@@ -82,8 +82,8 @@ fuzztest_cc_test(
     absl::flat_hash_map
     absl::flat_hash_set
     absl::random_random
-    fuzztest::coverage
     fuzztest::domain_core
+    fuzztest::table_of_recent_compares
     fuzztest::type_support
     GTest::gmock_main
 )
@@ -100,6 +100,7 @@ fuzztest_cc_library(
     absl::random_bit_gen_ref
     absl::status
     absl::strings
+    fuzztest::domain_core
     fuzztest::logging
     fuzztest::meta
     fuzztest::serialization
diff --git a/domain_tests/aggregate_combinators_test.cc b/domain_tests/aggregate_combinators_test.cc
index a99d5581..07d12e7f 100644
--- a/domain_tests/aggregate_combinators_test.cc
+++ b/domain_tests/aggregate_combinators_test.cc
@@ -82,7 +82,7 @@ TEST(StructOf, MutateGeneratesValidValues) {
   Set<std::string> field_s;
   Value agg(domain, bitgen);
   while (field_a.size() < 2 && field_s.size() < 10) {
-    agg.Mutate(domain, bitgen, false);
+    agg.Mutate(domain, bitgen, {}, false);
     EXPECT_THAT(agg.user_value.a, AnyOf(5, 10));
     field_a.insert(agg.user_value.a);
     field_s.insert(agg.user_value.s);
@@ -104,11 +104,11 @@ TEST(StructOf, WorksWithStructWithUpTo16Fields) {
   Value value(domain, bitgen);
   const uint32_t initial_sum = value.user_value.sum();
   while (value.user_value.sum() == initial_sum) {
-    value.Mutate(domain, bitgen, false);
+    value.Mutate(domain, bitgen, {}, false);
   }
   // Check that shrinking works too.
   while (value.user_value.sum() != 0) {
-    value.Mutate(domain, bitgen, true);
+    value.Mutate(domain, bitgen, {}, true);
   }
 }
 
@@ -151,7 +151,7 @@ TEST(ConstructorOf, MutateGeneratesValidValues) {
   Set<std::string> field_s;
   Value agg(domain, bitgen);
   while (field_a.size() < 2 && field_d.size() < 10 && field_s.size() < 10) {
-    agg.Mutate(domain, bitgen, false);
+    agg.Mutate(domain, bitgen, {}, false);
     EXPECT_THAT(agg.user_value.a(), AnyOf(5, 10));
     field_a.insert(agg.user_value.a());
     field_d.insert(agg.user_value.d());
@@ -181,11 +181,11 @@ TEST(ConstructorOf, WorksWithTemplatedConstructors) {
   Value value(domain, bitgen);
   const uint32_t initial_sum = value.user_value.sum();
   while (value.user_value.sum() == initial_sum) {
-    value.Mutate(domain, bitgen, false);
+    value.Mutate(domain, bitgen, {}, false);
   }
   // Check that shrinking works too.
   while (value.user_value.sum() != 0) {
-    value.Mutate(domain, bitgen, true);
+    value.Mutate(domain, bitgen, {}, true);
   }
 }
 
@@ -201,7 +201,7 @@ TEST(ConstructorOf, WorksWithMoveConstructors) {
   Value value(domain, bitgen);
   const std::string initial_value = value.user_value.data_;
   while (value.user_value.data_ == initial_value) {
-    value.Mutate(domain, bitgen, false);
+    value.Mutate(domain, bitgen, {}, false);
   }
 }
 
@@ -254,7 +254,7 @@ TEST(VariantOf, MutateGenerateValidValues) {
   Value value(domain, bitgen);
   while (unique_values[0].size() < 2 || unique_values[1].size() < n ||
          counter[2] < n || counter[3] < n) {
-    value.Mutate(domain, bitgen, false);
+    value.Mutate(domain, bitgen, {}, false);
     if (value.user_value.index() == 0) {
       int val = std::get<0>(value.user_value);
       EXPECT_THAT(val, AnyOf(5, 10));
@@ -325,7 +325,7 @@ TEST(OptionalOf, MutateCanMakeValuesOrNull) {
   absl::BitGen bitgen;
   Value value(domain, bitgen);
   while (values.size() < 4) {
-    value.Mutate(domain, bitgen, false);
+    value.Mutate(domain, bitgen, {}, false);
     values.insert(value.user_value);
   }
   EXPECT_THAT(values, UnorderedElementsAre(std::nullopt, Optional(1),
@@ -347,7 +347,7 @@ TEST(OptionalOf, AlwaysGenerateNulloptWhenPolicySet) {
   Value value(domain, bitgen);
   for (int i = 0; i < 10000; ++i) {
     EXPECT_TRUE(value == std::nullopt) << "Didn't expect non-null value!";
-    value.Mutate(domain, bitgen, false);
+    value.Mutate(domain, bitgen, {}, false);
   }
 }
 
@@ -359,7 +359,7 @@ TEST(OptionalOf, DoesntGenerateNulloptWhenPolicySet) {
   Value value(domain, bitgen);
   for (int i = 0; i < 10000; ++i) {
     EXPECT_TRUE(value != std::nullopt) << "Didn't expect null value!";
-    value.Mutate(domain, bitgen, false);
+    value.Mutate(domain, bitgen, {}, false);
   }
 }
 
diff --git a/domain_tests/arbitrary_domains_protobuf_test.cc b/domain_tests/arbitrary_domains_protobuf_test.cc
index 08ae160b..8ec6150e 100644
--- a/domain_tests/arbitrary_domains_protobuf_test.cc
+++ b/domain_tests/arbitrary_domains_protobuf_test.cc
@@ -91,7 +91,7 @@ TEST(ProtocolBuffer,
     int iterations = 10'000;
     while (--iterations > 0 && values.size() < 2) {
       values.insert(optional_get());
-      val.Mutate(domain, bitgen, false);
+      val.Mutate(domain, bitgen, {}, false);
     }
     EXPECT_GT(iterations, 0)
         << "Field: " << name << " -- " << testing::PrintToString(values);
@@ -109,7 +109,7 @@ TEST(ProtocolBuffer,
       if (field.size() > 0) {
         elem0.insert(field[0]);
       }
-      val.Mutate(domain, bitgen, false);
+      val.Mutate(domain, bitgen, {}, false);
     }
     EXPECT_GT(iterations, 0)
         << "Field: " << name << " -- " << testing::PrintToString(sizes)
@@ -146,7 +146,7 @@ TEST(ProtocolBuffer,
   Value val(domain, bitgen);
 
   for (int i = 0; i < 10'000; ++i) {
-    val.Mutate(domain, bitgen, /*only_shrink=*/false);
+    val.Mutate(domain, bitgen, {}, false);
   }
 
   // We verify that the object actually has things in it. This can technically
@@ -158,7 +158,7 @@ TEST(ProtocolBuffer,
   for (int iteration = 0;
        val.user_value.ByteSizeLong() > 0 && iteration < 50'000; ++iteration) {
     const auto prev = val;
-    val.Mutate(domain, bitgen, /*only_shrink=*/true);
+    val.Mutate(domain, bitgen, {}, true);
     ASSERT_TRUE(TowardsZero(prev.user_value, val.user_value))
         << prev << " -vs- " << val;
   }
@@ -175,7 +175,7 @@ TEST(ProtocolBufferWithRequiredFields, OptionalFieldIsEventuallySet) {
   ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
 
   for (int i = 0; i < 1000; ++i) {
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
     ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
     if (val.user_value.has_i32()) break;
   }
@@ -196,7 +196,7 @@ TEST(ProtocolBufferWithRequiredFields, OptionalFieldIsEventuallyUnset) {
   // at least 1/800. Hence, within 11000 iterations we'll fail to observe this
   // event with probability at most 10^(-6).
   for (int i = 0; i < 11000; ++i) {
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
     ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
     if (!val.user_value.has_i32()) break;
   }
@@ -214,7 +214,7 @@ TEST(ProtocolBufferWithRequiredFields, OptionalFieldInSubprotoIsEventuallySet) {
   ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
 
   for (int i = 0; i < 1000; ++i) {
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
     ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
     if (val.user_value.has_req_sub() &&
         val.user_value.req_sub().has_subproto_i32())
@@ -239,7 +239,7 @@ TEST(ProtocolBufferWithRequiredFields,
   // req_sub.subproto_i32 is at least 1/800. Hence, within 11000 iterations
   // we'll fail to observe this event with probability at most 10^(-6).
   for (int i = 0; i < 11000; ++i) {
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
     ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
     if (val.user_value.has_req_sub() &&
         !val.user_value.req_sub().has_subproto_i32())
@@ -271,7 +271,7 @@ TEST(ProtocolBufferWithRequiredFields,
   ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
 
   for (int i = 0; i < 1000; ++i) {
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
     ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
     if (val.user_value.has_sub_req()) {
       ASSERT_TRUE(val.user_value.sub_req().IsInitialized()) << val.user_value;
@@ -298,7 +298,7 @@ TEST(ProtocolBufferWithRequiredFields, MapFieldIsEventuallyPopulated) {
 
   bool found = false;
   for (int i = 0; i < 1000 && !found; ++i) {
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
     ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
     for (const auto& pair : val.user_value.map_sub_req()) {
       found = true;
@@ -324,7 +324,7 @@ TEST(ProtocolBufferWithRequiredFields, ShrinkingNeverRemovesRequiredFields) {
   ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
 
   for (int i = 0; i < 1000; ++i) {
-    val.Mutate(domain, bitgen, /*only_shrink=*/false);
+    val.Mutate(domain, bitgen, {}, false);
     ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
   }
 
@@ -335,7 +335,7 @@ TEST(ProtocolBufferWithRequiredFields, ShrinkingNeverRemovesRequiredFields) {
   };
 
   while (!is_minimal(val.user_value)) {
-    val.Mutate(domain, bitgen, /*only_shrink=*/true);
+    val.Mutate(domain, bitgen, {}, true);
     ASSERT_TRUE(val.user_value.IsInitialized()) << val.user_value;
   }
 }
@@ -375,7 +375,7 @@ TEST(ProtocolBuffer, CanUsePerFieldDomains) {
   while (i32_values.size() < i32_count || str_values.size() < str_count ||
          e_values.size() < e_count || rep_b_values.size() < rep_p_count ||
          subproto_i32_values.size() < subproto_i32_count) {
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
     if (val.user_value.has_i32()) i32_values.insert(val.user_value.i32());
     if (val.user_value.has_str()) str_values.insert(val.user_value.str());
     if (val.user_value.has_e()) e_values.insert(val.user_value.e());
@@ -616,9 +616,9 @@ TEST(ProtocolBufferEnum, Arbitrary) {
   Set<TestProtobuf_Enum> s;
   while (s.size() < internal::TestProtobuf_Enum_descriptor()->value_count()) {
     s.insert(val.user_value);
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
   }
-  val.Mutate(domain, bitgen, true);
+  val.Mutate(domain, bitgen, {}, true);
 }
 
 TEST(ArbitraryProtocolBufferEnum, InitGeneratesSeeds) {
diff --git a/domain_tests/arbitrary_domains_test.cc b/domain_tests/arbitrary_domains_test.cc
index d87e95be..24287595 100644
--- a/domain_tests/arbitrary_domains_test.cc
+++ b/domain_tests/arbitrary_domains_test.cc
@@ -49,6 +49,7 @@ namespace fuzztest {
 namespace {
 
 using ::fuzztest::domain_implementor::DomainBase;
+using ::fuzztest::domain_implementor::MutationMetadata;
 using ::fuzztest::internal::IRObject;
 using ::testing::Contains;
 using ::testing::Each;
@@ -67,9 +68,9 @@ TEST(BoolTest, Arbitrary) {
 
   Value b(domain, bitgen);
   bool copy = b.user_value;
-  b.Mutate(domain, bitgen, false);
+  b.Mutate(domain, bitgen, {}, false);
   EXPECT_NE(b.user_value, copy);
-  b.Mutate(domain, bitgen, false);
+  b.Mutate(domain, bitgen, {}, false);
   EXPECT_EQ(b.user_value, copy);
 }
 
@@ -186,7 +187,7 @@ TYPED_TEST(MonostateTypeTest, Arbitrary) {
   auto v = domain.Init(bitgen);
   // Mutate "works". That is, it returns.
   // We don't expect it to do anything else since the value can't be changed.
-  domain.Mutate(v, bitgen, false);
+  domain.Mutate(v, bitgen, {}, false);
 }
 
 struct BinaryTree {
@@ -207,7 +208,7 @@ TEST(UserDefinedAggregate, NestedArbitrary) {
   Set<int> s;
   while (s.size() < 10) {
     s.insert(v.user_value.count_nodes());
-    v.Mutate(domain, bitgen, false);
+    v.Mutate(domain, bitgen, {}, false);
   }
 }
 
@@ -223,7 +224,8 @@ struct StatefulIncrementDomain
     return result;
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const MutationMetadata& metadata, bool only_shrink) {
     std::get<0>(val) += absl::Uniform<value_type>(prng, 5, 6) +
                         static_cast<value_type>(only_shrink);
   }
@@ -279,9 +281,9 @@ TEST(Domain, BasicVerify) {
 
   Value i(domain, bitgen);
   Value j = i;
-  i.Mutate(domain, bitgen, false);
+  i.Mutate(domain, bitgen, {}, false);
   EXPECT_THAT(i.user_value, j.user_value + 5);
-  i.Mutate(domain, bitgen, true);
+  i.Mutate(domain, bitgen, {}, true);
   EXPECT_THAT(i.user_value, j.user_value + 11);
 }
 
diff --git a/domain_tests/container_combinators_test.cc b/domain_tests/container_combinators_test.cc
index 92268872..53a9324c 100644
--- a/domain_tests/container_combinators_test.cc
+++ b/domain_tests/container_combinators_test.cc
@@ -93,7 +93,7 @@ TEST(ContainerCombinatorTest, MinSizeCanBeLargerThanDefaultMaxSize) {
                     .WithMinSize(kDefaultMaxSize + 1);
   absl::BitGen bitgen;
   auto val = Value(domain, bitgen);
-  val.Mutate(domain, bitgen, /*only_shrink=*/false);
+  val.Mutate(domain, bitgen, {}, false);
   ASSERT_THAT(val.user_value, SizeIs(Gt(kDefaultMaxSize)));
 }
 
diff --git a/domain_tests/container_test.cc b/domain_tests/container_test.cc
index 1a3c1d91..0f361fc2 100644
--- a/domain_tests/container_test.cc
+++ b/domain_tests/container_test.cc
@@ -34,7 +34,7 @@
 #include "absl/random/random.h"
 #include "./fuzztest/domain_core.h"
 #include "./domain_tests/domain_testing.h"
-#include "./fuzztest/internal/coverage.h"
+#include "./fuzztest/internal/table_of_recent_compares.h"
 #include "./fuzztest/internal/type_support.h"
 
 namespace fuzztest {
@@ -109,7 +109,7 @@ void TestMinMaxContainerSize(Domain domain, size_t min_size, size_t max_size) {
 
     ASSERT_THAT(v.user_value, size_match);
     sizes.insert(v.user_value.size());
-    v.Mutate(domain, bitgen, false);
+    v.Mutate(domain, bitgen, {}, false);
     ASSERT_THAT(v.user_value, size_match);
 
     // Mutating the value can reach the max, but only for small max sizes
@@ -117,7 +117,7 @@ void TestMinMaxContainerSize(Domain domain, size_t min_size, size_t max_size) {
     if (max_size <= 10) {
       auto max_v = v;
       while (max_v.user_value.size() < max_size) {
-        v.Mutate(domain, bitgen, false);
+        v.Mutate(domain, bitgen, {}, false);
         if (v.user_value.size() > max_v.user_value.size()) {
           max_v = v;
         } else if (v.user_value.size() < max_v.user_value.size()) {
@@ -129,10 +129,10 @@ void TestMinMaxContainerSize(Domain domain, size_t min_size, size_t max_size) {
 
     // Shinking the value will reach the min.
     while (v.user_value.size() > min_size) {
-      v.Mutate(domain, bitgen, true);
+      v.Mutate(domain, bitgen, {}, true);
     }
     // Mutating again won't go below.
-    v.Mutate(domain, bitgen, true);
+    v.Mutate(domain, bitgen, {}, true);
     ASSERT_THAT(v.user_value, SizeIs(min_size));
   }
   // Check that there is some in between.
@@ -242,28 +242,16 @@ TEST(Container, ValidationRejectsInvalidElements) {
 // enabled, but we test on strings for simplification.
 TEST(Container, MemoryDictionaryMutationMutatesEveryPossibleMatch) {
   auto domain = Arbitrary<std::string>();
-  class ScopedExecutionCoverage {
-   public:
-    ScopedExecutionCoverage() { internal::SetExecutionCoverage(&coverage); }
-
-    ~ScopedExecutionCoverage() { internal::SetExecutionCoverage(nullptr); }
-
-   private:
-    internal::ExecutionCoverage coverage =
-        internal::ExecutionCoverage(/*counter_map=*/{});
-  };
-  ScopedExecutionCoverage scoped_coverage;
-  fuzztest::internal::GetExecutionCoverage()
-      ->GetTablesOfRecentCompares()
-      .GetMutable<0>()
-      .Insert(reinterpret_cast<const uint8_t*>("abcd"),
-              reinterpret_cast<const uint8_t*>("1234"), 4);
+  internal::TablesOfRecentCompares cmp_tables;
+  cmp_tables.GetMutable<0>().Insert(reinterpret_cast<const uint8_t*>("abcd"),
+                                    reinterpret_cast<const uint8_t*>("1234"),
+                                    4);
 
   absl::BitGen bitgen;
   std::vector<std::string> mutants;
   for (int i = 0; i < 1000000; ++i) {
     std::string mutant = "abcdabcdabcdabcd";
-    domain.Mutate(mutant, bitgen, false);
+    domain.Mutate(mutant, bitgen, {.cmp_tables = &cmp_tables}, false);
     mutants.push_back(std::move(mutant));
   }
 
diff --git a/domain_tests/domain_testing.h b/domain_tests/domain_testing.h
index eb156154..e8b9009a 100644
--- a/domain_tests/domain_testing.h
+++ b/domain_tests/domain_testing.h
@@ -35,6 +35,7 @@
 #include "absl/status/status.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/string_view.h"
+#include "./fuzztest/internal/domains/mutation_metadata.h"
 #include "./fuzztest/internal/logging.h"
 #include "./fuzztest/internal/meta.h"
 #include "./fuzztest/internal/serialization.h"
@@ -150,15 +151,20 @@ struct Value {
         }()),
         user_value(std::move(user_value)) {}
 
-  void Mutate(Domain& domain, absl::BitGenRef prng, bool only_shrink) {
-    domain.Mutate(corpus_value, prng, only_shrink);
+  void Mutate(Domain& domain, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
+    domain.Mutate(corpus_value, prng, metadata, only_shrink);
     user_value = domain.GetValue(corpus_value);
   }
 
-  void RandomizeByRepeatedMutation(Domain& domain, absl::BitGenRef prng) {
+  void RandomizeByRepeatedMutation(
+      Domain& domain, absl::BitGenRef prng,
+      const domain_implementor::MutationMetadata& metadata = {},
+      bool only_shrink = false) {
     static constexpr int kMutations = 1000;
     for (int i = 0; i < kMutations; ++i) {
-      domain.Mutate(corpus_value, prng, /*only_shrink=*/false);
+      domain.Mutate(corpus_value, prng, metadata, only_shrink);
     }
     user_value = domain.GetValue(corpus_value);
   }
@@ -255,8 +261,9 @@ template <typename Domain>
 Value(Domain&, absl::BitGenRef) -> Value<Domain>;
 
 template <typename Domain>
-auto GenerateValues(Domain domain, int num_seeds = 10,
-                    int num_mutations = 100) {
+auto GenerateValues(Domain domain, int num_seeds = 10, int num_mutations = 100,
+                    const domain_implementor::MutationMetadata& metadata = {},
+                    bool only_shrink = false) {
   absl::BitGen bitgen;
 
   absl::flat_hash_set<Value<Domain>> seeds;
@@ -275,7 +282,7 @@ auto GenerateValues(Domain domain, int num_seeds = 10,
     // As above, we repeat until we find enough unique ones.
     while (mutations.size() < num_mutations) {
       const auto previous = value;
-      value.Mutate(domain, bitgen, false);
+      value.Mutate(domain, bitgen, metadata, only_shrink);
       // Make sure that it changed in some way.
       mutations.insert(value);
       EXPECT_NE(previous, value) << "Value=" << value << " Prev=" << previous;
@@ -287,8 +294,10 @@ auto GenerateValues(Domain domain, int num_seeds = 10,
 }
 
 template <typename Domain>
-auto GenerateNonUniqueValues(Domain domain, int num_seeds = 10,
-                             int num_mutations = 100) {
+auto GenerateNonUniqueValues(
+    Domain domain, int num_seeds = 10, int num_mutations = 100,
+    const domain_implementor::MutationMetadata& metadata = {},
+    bool only_shrink = false) {
   absl::BitGen bitgen;
 
   std::vector<Value<Domain>> seeds;
@@ -302,7 +311,7 @@ auto GenerateNonUniqueValues(Domain domain, int num_seeds = 10,
     auto value = seed;
     std::vector<Value<Domain>> mutations = {value};
     while (mutations.size() < num_mutations) {
-      value.Mutate(domain, bitgen, false);
+      value.Mutate(domain, bitgen, metadata, only_shrink);
       mutations.push_back(value);
     }
     values.insert(values.end(), mutations.begin(), mutations.end());
@@ -330,28 +339,32 @@ void CheckValues(const Values& values, Pred pred) {
 }
 
 template <typename Domain>
-auto MutateUntilFoundN(Domain domain, size_t n) {
+auto MutateUntilFoundN(
+    Domain domain, size_t n,
+    const domain_implementor::MutationMetadata& metadata = {},
+    bool only_shrink = false) {
   absl::flat_hash_set<Value<Domain>> seen;
   absl::BitGen bitgen;
   Value val(domain, bitgen);
   while (seen.size() < n) {
     seen.insert(Value(val, domain));
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, metadata, only_shrink);
   }
   return seen;
 }
 
 template <typename Domain, typename IsTerminal, typename IsCloser,
           typename T = internal::value_type_t<Domain>>
-absl::Status TestShrink(Domain domain,
-                        const absl::flat_hash_set<Value<Domain>>& values,
-                        IsTerminal is_terminal, IsCloser is_closer_to_zero) {
+absl::Status TestShrink(
+    Domain domain, const absl::flat_hash_set<Value<Domain>>& values,
+    IsTerminal is_terminal, IsCloser is_closer_to_zero,
+    const domain_implementor::MutationMetadata& metadata = {}) {
   absl::BitGen bitgen;
 
   for (auto value : values) {
     while (!is_terminal(value.user_value)) {
       auto previous_value = value;
-      value.Mutate(domain, bitgen, true);
+      value.Mutate(domain, bitgen, metadata, true);
       if (value == previous_value) {
         return absl::InternalError(
             absl::StrCat("Mutate failed to produce a new value starting from ",
@@ -377,7 +390,7 @@ void TestShrink(Domain domain, const Values& values, Pred pred) {
 
   for (const auto& value : values) {
     auto other_value = value;
-    other_value.Mutate(domain, bitgen, true);
+    other_value.Mutate(domain, bitgen, {}, true);
     ASSERT_TRUE(pred(value.user_value, other_value.user_value))
         << value << " " << other_value;
   }
diff --git a/domain_tests/in_grammar_domain_test.cc b/domain_tests/in_grammar_domain_test.cc
index 196ab3ed..7b77aa73 100644
--- a/domain_tests/in_grammar_domain_test.cc
+++ b/domain_tests/in_grammar_domain_test.cc
@@ -69,7 +69,7 @@ TEST(InJsonGrammar, MutateGeneratesValidValues) {
   Value ast(domain, bitgen);
 
   while (valid_jsons.size() < 5000) {
-    ast.Mutate(domain, bitgen, false);
+    ast.Mutate(domain, bitgen, {}, false);
     nlohmann::json parsed_json = nlohmann::json::parse(
         ast.user_value.begin(), ast.user_value.end(), nullptr, false);
     EXPECT_FALSE(parsed_json.is_discarded());
@@ -88,7 +88,7 @@ TEST(InJsonGrammar, MutateGeneratesDifferentValuesWithHighProb) {
 
   while (valid_jsons.size() < 5000) {
     ++num_total_mutation;
-    ast.Mutate(domain, bitgen, false);
+    ast.Mutate(domain, bitgen, {}, false);
     nlohmann::json parsed_json = nlohmann::json::parse(
         ast.user_value.begin(), ast.user_value.end(), nullptr, false);
     valid_jsons.insert(parsed_json.dump());
@@ -116,7 +116,7 @@ TEST(InJsonGrammar, ShrinkModeReducesInputSize) {
     if (original_size > 20) ++expected_num_of_successful_shrink;
 
     for (int j = 0; j < 10; ++j) {
-      val.Mutate(domain, bitgen, true);
+      val.Mutate(domain, bitgen, {}, true);
       EXPECT_TRUE(val.corpus_value.NodeCount() <= original_size);
     }
     if (original_size > val.corpus_value.NodeCount()) {
diff --git a/domain_tests/in_regexp_domain_test.cc b/domain_tests/in_regexp_domain_test.cc
index 7e1d7dce..c7fe54dc 100644
--- a/domain_tests/in_regexp_domain_test.cc
+++ b/domain_tests/in_regexp_domain_test.cc
@@ -99,7 +99,7 @@ TEST(InRegexp, MutationGeneratesDifferentValidValues) {
     EXPECT_TRUE(RE2::FullMatch(val.user_value, regexp));
 
     while (unique_values.size() < num_unique_values) {
-      val.Mutate(domain, bitgen, false);
+      val.Mutate(domain, bitgen, {}, false);
       EXPECT_TRUE(RE2::FullMatch(val.user_value, regexp));
       unique_values.insert(val.user_value);
     }
@@ -119,7 +119,7 @@ TEST(InRegexp, MutatingRepetitionCanIncreaseAndDecreaseLength) {
   constexpr int mutate_times = 50000;
   for (int i = 0; i < mutate_times; ++i) {
     val.corpus_value = domain.FromValue("aaaaa").value();
-    val.Mutate(domain, bitgen, false);
+    val.Mutate(domain, bitgen, {}, false);
     size_t size_after_mutation = val.user_value.size();
     ASSERT_LT(size_after_mutation, 7) << val.user_value;
     ++size_histogram[size_after_mutation];
@@ -161,7 +161,7 @@ TEST(InRegexp, OnlyShrinkFindsDifferentValueWithMinimalLength) {
       Value val(domain, bitgen);
       while (val.user_value.size() != expected_length) {
         size_t pre_size = val.user_value.size();
-        val.Mutate(domain, bitgen, /*only_shrink=*/true);
+        val.Mutate(domain, bitgen, {}, true);
         if (min_path_length_equal_min_string_length) {
           ASSERT_LE(val.user_value.size(), pre_size) << val.user_value;
         }
diff --git a/domain_tests/map_filter_combinator_test.cc b/domain_tests/map_filter_combinator_test.cc
index cc805395..0c04638a 100644
--- a/domain_tests/map_filter_combinator_test.cc
+++ b/domain_tests/map_filter_combinator_test.cc
@@ -261,7 +261,7 @@ TEST(FlatMap, MutationAcceptsChangingDomains) {
     // We demand that our output domain has size `len` above. This will check
     // fail in ContainerOfImpl if we try to generate a string of the wrong
     // length.
-    domain.Mutate(mutated, bitgen, false);
+    domain.Mutate(mutated, bitgen, {}, false);
   }
   EXPECT_EQ(domain.GetValue(mutated).size(), std::get<1>(mutated));
 }
@@ -277,7 +277,7 @@ TEST(FlatMap, MutationAcceptsShrinkingOutputDomains) {
   }
   auto mutated = value->corpus_value;
   while (!domain.GetValue(mutated).empty()) {
-    domain.Mutate(mutated, bitgen, true);
+    domain.Mutate(mutated, bitgen, {}, true);
   }
   EXPECT_THAT(domain.GetValue(mutated), IsEmpty());
 }
@@ -298,7 +298,7 @@ TEST(FlatMap, MutationDoesNotAlterInputDomains) {
   auto mutated = value->corpus_value;
   const size_t original_size = value->user_value.size();
   while (!all_zeros(domain.GetValue(mutated))) {
-    domain.Mutate(mutated, bitgen, true);
+    domain.Mutate(mutated, bitgen, {}, true);
     EXPECT_THAT(domain.GetValue(mutated).size(), Eq(original_size));
   }
   EXPECT_THAT(domain.GetValue(mutated), Each(Eq(0)));
@@ -341,7 +341,7 @@ TEST(Filter, CanFilterMutateCalls) {
   Value value(domain, bitgen);
   Set<int> seen;
   while (seen.size() < 5) {
-    value.Mutate(domain, bitgen, false);
+    value.Mutate(domain, bitgen, {}, false);
     seen.insert(value.user_value);
   }
   EXPECT_THAT(seen, UnorderedElementsAre(2, 4, 6, 8, 10));
diff --git a/domain_tests/misc_domains_test.cc b/domain_tests/misc_domains_test.cc
index a3a6d53b..9cc27ee1 100644
--- a/domain_tests/misc_domains_test.cc
+++ b/domain_tests/misc_domains_test.cc
@@ -61,7 +61,7 @@ TEST(BitFlagCombinationOf, Ints) {
   int val = 1 | 4 | 16 | 32;
   while (val != 0) {
     int prev = val;
-    domain.Mutate(val, bitgen, true);
+    domain.Mutate(val, bitgen, {}, true);
     // val can't have new bits set.
     EXPECT_EQ(prev & val, val);
     EXPECT_EQ(prev | val, prev);
@@ -133,7 +133,7 @@ TEST(OneOf, AllSubDomainsArePickedEventually) {
   elems.clear();
   Value mutated(domain, bitgen);
   while (elems.size() < 5) {
-    mutated.Mutate(domain, bitgen, false);
+    mutated.Mutate(domain, bitgen, {}, false);
     elems.insert(mutated.user_value);
 
     VerifyRoundTripThroughConversion(mutated, domain);
@@ -155,13 +155,13 @@ TEST(OneOf, Mutate) {
     } else {
       v.corpus_value = std::variant<int, int>(std::in_place_index_t<1>{}, k);
     }
-    v.Mutate(domain, bitgen, /*only_shrink=*/false);
+    v.Mutate(domain, bitgen, {}, false);
     ASSERT_NE(k, v.user_value);
   }
   for (int i = 0; i < kRuns; ++i) {
     Value v(domain, bitgen);
     int old_k = v.user_value;
-    v.Mutate(domain, bitgen, /*only_shrink=*/true);
+    v.Mutate(domain, bitgen, {}, true);
     int new_k = v.user_value;
     if ((new_k >= 0) == (old_k >= 0)) {
       EXPECT_LE(std::abs(new_k), std::abs(old_k))
@@ -181,7 +181,7 @@ TEST(OneOf, SwitchesDomains) {
   absl::flat_hash_set<Color> found;
   Value v(domain, bitgen);
   while (found.size() < all_colors.size()) {
-    v.Mutate(domain, bitgen, /*only_shrink=*/false);
+    v.Mutate(domain, bitgen, {}, false);
     found.insert(v.user_value);
   }
   ASSERT_THAT(found, UnorderedElementsAreArray(all_colors));
diff --git a/domain_tests/numeric_domains_test.cc b/domain_tests/numeric_domains_test.cc
index 492e9f03..e8cf2326 100644
--- a/domain_tests/numeric_domains_test.cc
+++ b/domain_tests/numeric_domains_test.cc
@@ -352,7 +352,7 @@ TEST(InRange, SupportsSingletonRange) {
   auto domain = InRange(10, 10);
   absl::BitGen bitgen;
   auto val = Value(domain, bitgen);
-  val.Mutate(domain, bitgen, /*only_shrink=*/false);
+  val.Mutate(domain, bitgen, {}, false);
 
   EXPECT_EQ(val.user_value, 10);
 }
@@ -379,11 +379,11 @@ TEST(IllegalInputs, Numeric) {
   const std::vector<int> values{-10, -1, 0, 1};
   auto restricted_domain = Positive<int>();
   for (int value : values) {
-    restricted_domain.Mutate(value, bitgen, false);
+    restricted_domain.Mutate(value, bitgen, {}, false);
     ASSERT_GT(value, 0);
   }
   for (int value : values) {
-    restricted_domain.Mutate(value, bitgen, true);
+    restricted_domain.Mutate(value, bitgen, {}, true);
     ASSERT_GT(value, 0);
   }
 }
diff --git a/domain_tests/pointer_domains_test.cc b/domain_tests/pointer_domains_test.cc
index fe1b5360..58ceedc0 100644
--- a/domain_tests/pointer_domains_test.cc
+++ b/domain_tests/pointer_domains_test.cc
@@ -41,7 +41,7 @@ void TestSmartPointer(Domain domain) {
 
     Set<std::optional<int>> mutations;
     while (mutations.size() < 4) {
-      value.Mutate(domain, bitgen, false);
+      value.Mutate(domain, bitgen, {}, false);
       mutations.insert(value.user_value ? std::optional(*value.user_value)
                                         : std::nullopt);
     }
diff --git a/domain_tests/recursive_domains_test.cc b/domain_tests/recursive_domains_test.cc
index e9072884..29dfd58c 100644
--- a/domain_tests/recursive_domains_test.cc
+++ b/domain_tests/recursive_domains_test.cc
@@ -57,7 +57,7 @@ TEST(DomainBuilder, DomainForRecursiveDataStructureCreatesUniqueObjects) {
   Value tree(domain, bitgen);
 
   while (true) {
-    tree.Mutate(domain, bitgen, false);
+    tree.Mutate(domain, bitgen, {}, false);
     if (tree.user_value.children.empty()) continue;
     if (tree.user_value.children[0].children.empty()) continue;
     if (tree.user_value.children[0].children[0].children.empty()) continue;
@@ -98,7 +98,7 @@ TEST(DomainBuilder,
   absl::BitGen bitgen;
   Value redtree(domain_redtree, bitgen);
   while (true) {
-    redtree.Mutate(domain_redtree, bitgen, false);
+    redtree.Mutate(domain_redtree, bitgen, {}, false);
     if (redtree.user_value.children.empty()) continue;
     if (redtree.user_value.children[0].children.empty()) continue;
     if (redtree.user_value.children[0].children[0].children.empty()) continue;
diff --git a/domain_tests/specific_value_domains_test.cc b/domain_tests/specific_value_domains_test.cc
index 215a6f98..d65ca099 100644
--- a/domain_tests/specific_value_domains_test.cc
+++ b/domain_tests/specific_value_domains_test.cc
@@ -50,7 +50,7 @@ TEST(ElementOfTest, TwoOptions) {
 
   for (const auto& v : found) {
     auto copy = v;
-    copy.Mutate(domain, bitgen, false);
+    copy.Mutate(domain, bitgen, {}, false);
     EXPECT_NE(v, copy);
   }
 }
@@ -87,7 +87,7 @@ TEST(ElementOfTest, Colors) {
   found.clear();
   Value c(domain, bitgen);
   while (found.size() < all_colors.size()) {
-    c.Mutate(domain, bitgen, false);
+    c.Mutate(domain, bitgen, {}, false);
     found.insert(c.user_value);
 
     VerifyRoundTripThroughConversion(c, domain);
@@ -97,7 +97,7 @@ TEST(ElementOfTest, Colors) {
   c = Value(domain, bitgen);
   while (c.user_value != Color::Red) {
     auto prev = c.user_value;
-    c.Mutate(domain, bitgen, true);
+    c.Mutate(domain, bitgen, {}, true);
     ASSERT_LE(c.user_value, prev);
   }
   ASSERT_THAT(found, UnorderedElementsAreArray(all_colors));
@@ -146,7 +146,7 @@ TEST(Just, Basic) {
   int n = 3;
   for (int i = 0; i < 10; ++i) {
     Value v(domain, bitgen);
-    v.Mutate(domain, bitgen, false);
+    v.Mutate(domain, bitgen, {}, false);
 
     VerifyRoundTripThroughConversion(v, domain);
     EXPECT_EQ(n, 3);
diff --git a/domain_tests/string_domains_test.cc b/domain_tests/string_domains_test.cc
index 057b0371..4b1b7f5b 100644
--- a/domain_tests/string_domains_test.cc
+++ b/domain_tests/string_domains_test.cc
@@ -96,7 +96,7 @@ TEST(Domain, Forwarding) {
   elems.clear();
   Value c(domain, bitgen);
   while (elems.size() < 'z' - 'a' + 1) {
-    c.Mutate(domain, bitgen, false);
+    c.Mutate(domain, bitgen, {}, false);
     elems.insert(c.user_value);
   }
 }
diff --git a/fuzztest/BUILD b/fuzztest/BUILD
index 65dcf275..c6f58888 100644
--- a/fuzztest/BUILD
+++ b/fuzztest/BUILD
@@ -155,6 +155,7 @@ cc_library(
     testonly = True,
     srcs = ["llvm_fuzzer_wrapper.cc"],
     deps = [
+        ":coverage",
         ":domain_core",
         ":fuzztest",
         ":fuzztest_macros",
@@ -210,11 +211,11 @@ cc_library(
         ":any",
         ":configuration",
         ":corpus_database",
-        ":coverage",
         ":domain_core",
         ":fixture_driver",
         ":logging",
         ":runtime",
+        ":table_of_recent_compares",
         "@com_google_absl//absl/algorithm:container",
         "@com_google_absl//absl/log",
         "@com_google_absl//absl/memory",
@@ -303,6 +304,7 @@ cc_library(
         "//conditions:default": [],
     }),
     deps = [
+        ":domain_core",
         ":flag_name",
         ":logging",
         ":table_of_recent_compares",
@@ -366,6 +368,7 @@ cc_library(
         "internal/domains/flat_map_impl.h",
         "internal/domains/in_range_impl.h",
         "internal/domains/map_impl.h",
+        "internal/domains/mutation_metadata.h",
         "internal/domains/one_of_impl.h",
         "internal/domains/optional_of_impl.h",
         "internal/domains/overlap_of_impl.h",
@@ -380,7 +383,6 @@ cc_library(
     deps = [
         ":absl_helpers",
         ":any",
-        ":coverage",
         ":logging",
         ":meta",
         ":printer",
diff --git a/fuzztest/CMakeLists.txt b/fuzztest/CMakeLists.txt
index 5091c512..92f2878d 100644
--- a/fuzztest/CMakeLists.txt
+++ b/fuzztest/CMakeLists.txt
@@ -119,6 +119,7 @@ fuzztest_cc_library(
   SRCS
     "llvm_fuzzer_wrapper.cc"
   DEPS
+    fuzztest::coverage
     fuzztest::domain_core
     fuzztest::fuzztest
     fuzztest::io
@@ -241,6 +242,7 @@ fuzztest_cc_library(
   SRCS
     "internal/coverage.cc"
   DEPS
+    fuzztest::domain_core
     fuzztest::flag_name
     fuzztest::logging
     fuzztest::table_of_recent_compares
@@ -299,6 +301,7 @@ fuzztest_cc_library(
     "internal/domains/flat_map_impl.h"
     "internal/domains/in_range_impl.h"
     "internal/domains/map_impl.h"
+    "internal/domains/mutation_metadata.h"
     "internal/domains/one_of_impl.h"
     "internal/domains/optional_of_impl.h"
     "internal/domains/overlap_of_impl.h"
@@ -313,7 +316,6 @@ fuzztest_cc_library(
   DEPS
     fuzztest::absl_helpers
     fuzztest::any
-    fuzztest::coverage
     fuzztest::logging
     fuzztest::meta
     fuzztest::printer
diff --git a/fuzztest/domain_core.h b/fuzztest/domain_core.h
index eee4a928..1de526e2 100644
--- a/fuzztest/domain_core.h
+++ b/fuzztest/domain_core.h
@@ -162,12 +162,16 @@ class DomainBuilder {
       return GetInnerDomain().Init(prng);
     }
 
-    void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
-      GetInnerDomain().Mutate(val, prng, only_shrink);
+    void Mutate(corpus_type& val, absl::BitGenRef prng,
+                const domain_implementor::MutationMetadata& metadata,
+                bool only_shrink) {
+      GetInnerDomain().Mutate(val, prng, metadata, only_shrink);
     }
 
-    void UpdateMemoryDictionary(const corpus_type& val) {
-      return GetInnerDomain().UpdateMemoryDictionary(val);
+    void UpdateMemoryDictionary(
+        const corpus_type& val,
+        domain_implementor::ConstCmpTablesPtr cmp_tables) {
+      return GetInnerDomain().UpdateMemoryDictionary(val, cmp_tables);
     }
 
     auto GetPrinter() const { return GetInnerDomain().GetPrinter(); }
@@ -216,12 +220,16 @@ class DomainBuilder {
 
     corpus_type Init(absl::BitGenRef prng) { return inner_.Init(prng); }
 
-    void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
-      inner_.Mutate(val, prng, only_shrink);
+    void Mutate(corpus_type& val, absl::BitGenRef prng,
+                const domain_implementor::MutationMetadata& metadata,
+                bool only_shrink) {
+      inner_.Mutate(val, prng, metadata, only_shrink);
     }
 
-    void UpdateMemoryDictionary(const corpus_type& val) {
-      return inner_.UpdateMemoryDictionary(val);
+    void UpdateMemoryDictionary(
+        const corpus_type& val,
+        domain_implementor::ConstCmpTablesPtr cmp_tables) {
+      return inner_.UpdateMemoryDictionary(val, cmp_tables);
     }
 
     auto GetPrinter() const { return inner_.GetPrinter(); }
diff --git a/fuzztest/internal/centipede_adaptor.cc b/fuzztest/internal/centipede_adaptor.cc
index 9e74688b..de9961e0 100644
--- a/fuzztest/internal/centipede_adaptor.cc
+++ b/fuzztest/internal/centipede_adaptor.cc
@@ -62,11 +62,11 @@
 #include "./fuzztest/internal/any.h"
 #include "./fuzztest/internal/configuration.h"
 #include "./fuzztest/internal/corpus_database.h"
-#include "./fuzztest/internal/coverage.h"
 #include "./fuzztest/internal/domains/domain.h"
 #include "./fuzztest/internal/fixture_driver.h"
 #include "./fuzztest/internal/logging.h"
 #include "./fuzztest/internal/runtime.h"
+#include "./fuzztest/internal/table_of_recent_compares.h"
 
 namespace fuzztest::internal {
 namespace {
@@ -162,12 +162,6 @@ class CentipedeAdaptorRunnerCallbacks : public centipede::RunnerCallbacks {
         fuzzer_impl_(*fuzzer_impl),
         configuration_(*configuration),
         prng_(GetRandomSeed()) {
-    if (GetExecutionCoverage() == nullptr) {
-      execution_coverage_ = std::make_unique<ExecutionCoverage>(
-          /*counter_map=*/absl::Span<uint8_t>{});
-      execution_coverage_->SetIsTracing(true);
-      SetExecutionCoverage(execution_coverage_.get());
-    }
   }
 
   bool Execute(centipede::ByteSpan input) override {
@@ -254,7 +248,7 @@ class CentipedeAdaptorRunnerCallbacks : public centipede::RunnerCallbacks {
           parsed_origin = fuzzer_impl_.params_domain_.Init(prng_);
         }
         auto mutant = FuzzTestFuzzerImpl::Input{*std::move(parsed_origin)};
-        fuzzer_impl_.MutateValue(mutant, prng_);
+        fuzzer_impl_.MutateValue(mutant, prng_, {.cmp_tables = &cmp_tables_});
         mutant_data =
             fuzzer_impl_.params_domain_.SerializeCorpus(mutant.args).ToString();
       }
@@ -266,27 +260,22 @@ class CentipedeAdaptorRunnerCallbacks : public centipede::RunnerCallbacks {
 
   ~CentipedeAdaptorRunnerCallbacks() override {
     runtime_.UnsetCurrentArgs();
-    if (GetExecutionCoverage() == execution_coverage_.get())
-      SetExecutionCoverage(nullptr);
   }
 
  private:
   template <typename T>
-  static void InsertCmpEntryIntoIntegerDictionary(const uint8_t* a,
-                                                  const uint8_t* b) {
+  void InsertCmpEntryIntoIntegerDictionary(const uint8_t* a, const uint8_t* b) {
     T a_int;
     T b_int;
     memcpy(&a_int, a, sizeof(T));
     memcpy(&b_int, b, sizeof(T));
-    GetExecutionCoverage()
-        ->GetTablesOfRecentCompares()
-        .GetMutable<sizeof(T)>()
-        .Insert(a_int, b_int);
+    cmp_tables_.GetMutable<sizeof(T)>().Insert(a_int, b_int);
   }
 
   void SetMetadata(const centipede::ExecutionMetadata* metadata) {
     if (metadata == nullptr) return;
-    metadata->ForEachCmpEntry([](centipede::ByteSpan a, centipede::ByteSpan b) {
+    metadata->ForEachCmpEntry([this](centipede::ByteSpan a,
+                                     centipede::ByteSpan b) {
       FUZZTEST_INTERNAL_CHECK(a.size() == b.size(),
                               "cmp operands must have the same size");
       const size_t size = a.size();
@@ -299,10 +288,7 @@ class CentipedeAdaptorRunnerCallbacks : public centipede::RunnerCallbacks {
       } else if (size == 8) {
         InsertCmpEntryIntoIntegerDictionary<uint64_t>(a.data(), b.data());
       }
-      GetExecutionCoverage()
-          ->GetTablesOfRecentCompares()
-          .GetMutable<0>()
-          .Insert(a.data(), b.data(), size);
+      cmp_tables_.GetMutable<0>().Insert(a.data(), b.data(), size);
     });
   }
 
@@ -313,7 +299,7 @@ class CentipedeAdaptorRunnerCallbacks : public centipede::RunnerCallbacks {
   Runtime& runtime_;
   FuzzTestFuzzerImpl& fuzzer_impl_;
   const Configuration& configuration_;
-  std::unique_ptr<ExecutionCoverage> execution_coverage_;
+  internal::TablesOfRecentCompares cmp_tables_;
   absl::BitGen prng_;
 };
 
@@ -409,7 +395,6 @@ class CentipedeAdaptorEngineCallbacks : public centipede::CentipedeCallbacks {
   CentipedeAdaptorRunnerCallbacks runner_callbacks_;
   size_t batch_result_buffer_size_;
   uint8_t* batch_result_buffer_;
-  std::unique_ptr<ExecutionCoverage> execution_coverage_;
 };
 
 class CentipedeAdaptorEngineCallbacksFactory
diff --git a/fuzztest/internal/domains/aggregate_of_impl.h b/fuzztest/internal/domains/aggregate_of_impl.h
index ef04061e..d51a5cea 100644
--- a/fuzztest/internal/domains/aggregate_of_impl.h
+++ b/fuzztest/internal/domains/aggregate_of_impl.h
@@ -53,6 +53,8 @@ class AggregateOfImpl
   using typename AggregateOfImpl::DomainBase::corpus_type;
   using typename AggregateOfImpl::DomainBase::value_type;
 
+  using AggregateOfImpl::DomainBase::Mutate;
+
   AggregateOfImpl() = default;
   explicit AggregateOfImpl(std::in_place_t, Inner... inner)
       : inner_(std::move(inner)...) {}
@@ -64,7 +66,9 @@ class AggregateOfImpl
         inner_);
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     std::integral_constant<int, sizeof...(Inner)> size;
     auto bound = internal::BindAggregate(val, size);
     // Filter the tuple to only the mutable fields.
@@ -79,12 +83,14 @@ class AggregateOfImpl
       int offset = absl::Uniform<int>(prng, 0, actual_size);
       Switch<actual_size>(offset, [&](auto I) {
         std::get<to_mutate[I]>(inner_).Mutate(std::get<to_mutate[I]>(bound),
-                                              prng, only_shrink);
+                                              prng, metadata, only_shrink);
       });
     }
   }
 
-  void UpdateMemoryDictionary(const corpus_type& val) {
+  void UpdateMemoryDictionary(
+      const corpus_type& val,
+      domain_implementor::ConstCmpTablesPtr cmp_tables) {
     // Copy codes from Mutate that does the mutable domain filtering things.
     std::integral_constant<int, sizeof...(Inner)> size;
     auto bound = internal::BindAggregate(val, size);
@@ -97,7 +103,7 @@ class AggregateOfImpl
     if constexpr (actual_size > 0) {
       ApplyIndex<actual_size>([&](auto... I) {
         (std::get<to_mutate[I]>(inner_).UpdateMemoryDictionary(
-             std::get<to_mutate[I]>(bound)),
+             std::get<to_mutate[I]>(bound), cmp_tables),
          ...);
       });
     }
diff --git a/fuzztest/internal/domains/arbitrary_impl.h b/fuzztest/internal/domains/arbitrary_impl.h
index a709ec45..f0ca017f 100644
--- a/fuzztest/internal/domains/arbitrary_impl.h
+++ b/fuzztest/internal/domains/arbitrary_impl.h
@@ -33,7 +33,6 @@
 #include "absl/random/distributions.h"
 #include "absl/strings/string_view.h"
 #include "absl/time/time.h"
-#include "./fuzztest/internal/coverage.h"
 #include "./fuzztest/internal/domains/absl_helpers.h"
 #include "./fuzztest/internal/domains/aggregate_of_impl.h"
 #include "./fuzztest/internal/domains/container_of_impl.h"
@@ -73,9 +72,12 @@ class ArbitraryImpl<T, std::enable_if_t<is_monostate_v<T>>>
  public:
   using typename ArbitraryImpl::DomainBase::value_type;
 
+  using ArbitraryImpl::DomainBase::Mutate;
+
   value_type Init(absl::BitGenRef) { return value_type{}; }
 
-  void Mutate(value_type&, absl::BitGenRef, bool) {}
+  void Mutate(value_type&, absl::BitGenRef,
+              const domain_implementor::MutationMetadata&, bool) {}
 
   value_type GetRandomCorpusValue(absl::BitGenRef prng) { return value_type{}; }
 
@@ -91,12 +93,15 @@ template <>
 class ArbitraryImpl<bool>
     : public domain_implementor::DomainBase<ArbitraryImpl<bool>> {
  public:
+  using ArbitraryImpl::DomainBase::Mutate;
+
   value_type Init(absl::BitGenRef prng) {
     if (auto seed = MaybeGetRandomSeed(prng)) return *seed;
     return static_cast<bool>(absl::Uniform(prng, 0, 2));
   }
 
-  void Mutate(value_type& val, absl::BitGenRef, bool only_shrink) {
+  void Mutate(value_type& val, absl::BitGenRef,
+              const domain_implementor::MutationMetadata&, bool only_shrink) {
     if (only_shrink) {
       val = false;
     } else {
@@ -121,6 +126,8 @@ class ArbitraryImpl<T, std::enable_if_t<!std::is_const_v<T> &&
  public:
   using typename ArbitraryImpl::DomainBase::value_type;
 
+  using ArbitraryImpl::DomainBase::Mutate;
+
   static constexpr bool is_memory_dictionary_compatible_v =
       sizeof(T) == 1 || sizeof(T) == 2 || sizeof(T) == 4 || sizeof(T) == 8;
   using IntegerDictionaryT =
@@ -137,7 +144,9 @@ class ArbitraryImpl<T, std::enable_if_t<!std::is_const_v<T> &&
     }
   }
 
-  void Mutate(value_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(value_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     permanent_dict_candidate_ = std::nullopt;
     if (only_shrink) {
       if (val == 0) return;
@@ -152,10 +161,10 @@ class ArbitraryImpl<T, std::enable_if_t<!std::is_const_v<T> &&
       if (absl::Bernoulli(prng, 0.25)) {
         RandomBitFlip(prng, val, sizeof(T) * 8);
       } else {
-        RandomWalkOrUniformOrDict<5>(prng, val, std::numeric_limits<T>::min(),
-                                     std::numeric_limits<T>::max(),
-                                     temporary_dict_, permanent_dict_,
-                                     permanent_dict_candidate_);
+        RandomWalkOrUniformOrDict<5>(
+            prng, val, std::numeric_limits<T>::min(),
+            std::numeric_limits<T>::max(), metadata.cmp_tables, temporary_dict_,
+            permanent_dict_, permanent_dict_candidate_);
       }
       // Make sure Mutate really mutates.
     } while (val == prev);
@@ -166,12 +175,13 @@ class ArbitraryImpl<T, std::enable_if_t<!std::is_const_v<T> &&
     return ChooseFromAll(prng);
   }
 
-  void UpdateMemoryDictionary(const value_type& val) {
+  void UpdateMemoryDictionary(
+      const value_type& val, domain_implementor::ConstCmpTablesPtr cmp_tables) {
     if constexpr (is_memory_dictionary_compatible_v) {
-      if (GetExecutionCoverage() != nullptr) {
+      if (cmp_tables != nullptr) {
         temporary_dict_.MatchEntriesFromTableOfRecentCompares(
-            val, GetExecutionCoverage()->GetTablesOfRecentCompares(),
-            std::numeric_limits<T>::min(), std::numeric_limits<T>::max());
+            val, *cmp_tables, std::numeric_limits<T>::min(),
+            std::numeric_limits<T>::max());
         if (permanent_dict_candidate_.has_value() &&
             permanent_dict_.Size() < kPermanentDictMaxSize) {
           permanent_dict_.AddEntry(std::move(*permanent_dict_candidate_));
@@ -216,14 +226,18 @@ class ArbitraryImpl<std::byte>
   using typename ArbitraryImpl::DomainBase::corpus_type;
   using typename ArbitraryImpl::DomainBase::value_type;
 
+  using ArbitraryImpl::DomainBase::Mutate;
+
   value_type Init(absl::BitGenRef prng) {
     if (auto seed = this->MaybeGetRandomSeed(prng)) return *seed;
     return std::byte{inner_.Init(prng)};
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     unsigned char u8 = std::to_integer<unsigned char>(val);
-    inner_.Mutate(u8, prng, only_shrink);
+    inner_.Mutate(u8, prng, metadata, only_shrink);
     val = std::byte{u8};
   }
 
@@ -246,13 +260,16 @@ class ArbitraryImpl<T, std::enable_if_t<std::is_floating_point_v<T>>>
  public:
   using typename ArbitraryImpl::DomainBase::value_type;
 
+  using ArbitraryImpl::DomainBase::Mutate;
+
   value_type Init(absl::BitGenRef prng) {
     if (auto seed = this->MaybeGetRandomSeed(prng)) return *seed;
     return ChooseOneOr(SpecialValues<T>::Get(), prng,
                        [&] { return absl::Uniform(prng, T{0}, T{1}); });
   }
 
-  void Mutate(value_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(value_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata&, bool only_shrink) {
     if (only_shrink) {
       if (!std::isfinite(val) || val == 0) return;
       val = ShrinkTowards(prng, val, T{0});
@@ -318,17 +335,23 @@ class ArbitraryImpl<std::basic_string_view<Char>>
   using typename ArbitraryImpl::DomainBase::corpus_type;
   using typename ArbitraryImpl::DomainBase::value_type;
 
+  using ArbitraryImpl::DomainBase::Mutate;
+
   corpus_type Init(absl::BitGenRef prng) {
     if (auto seed = this->MaybeGetRandomSeed(prng)) return *seed;
     return inner_.Init(prng);
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
-    inner_.Mutate(val, prng, only_shrink);
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
+    inner_.Mutate(val, prng, metadata, only_shrink);
   }
 
-  void UpdateMemoryDictionary(const corpus_type& val) {
-    inner_.UpdateMemoryDictionary(val);
+  void UpdateMemoryDictionary(
+      const corpus_type& val,
+      domain_implementor::ConstCmpTablesPtr cmp_tables) {
+    inner_.UpdateMemoryDictionary(val, cmp_tables);
   }
 
   auto GetPrinter() const { return StringPrinter{}; }
@@ -373,17 +396,23 @@ class ArbitraryImpl<absl::string_view>
   using typename ArbitraryImpl::DomainBase::corpus_type;
   using typename ArbitraryImpl::DomainBase::value_type;
 
+  using ArbitraryImpl::DomainBase::Mutate;
+
   corpus_type Init(absl::BitGenRef prng) {
     if (auto seed = this->MaybeGetRandomSeed(prng)) return *seed;
     return inner_.Init(prng);
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
-    inner_.Mutate(val, prng, only_shrink);
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
+    inner_.Mutate(val, prng, metadata, only_shrink);
   }
 
-  void UpdateMemoryDictionary(const corpus_type& val) {
-    inner_.UpdateMemoryDictionary(val);
+  void UpdateMemoryDictionary(
+      const corpus_type& val,
+      domain_implementor::ConstCmpTablesPtr cmp_tables) {
+    inner_.UpdateMemoryDictionary(val, cmp_tables);
   }
 
   auto GetPrinter() const { return StringPrinter{}; }
diff --git a/fuzztest/internal/domains/bit_flag_combination_of_impl.h b/fuzztest/internal/domains/bit_flag_combination_of_impl.h
index 2a56d023..ce7642e6 100644
--- a/fuzztest/internal/domains/bit_flag_combination_of_impl.h
+++ b/fuzztest/internal/domains/bit_flag_combination_of_impl.h
@@ -33,11 +33,14 @@ class BitFlagCombinationOfImpl
  public:
   using typename BitFlagCombinationOfImpl::DomainBase::value_type;
 
+  using BitFlagCombinationOfImpl::DomainBase::Mutate;
+
   explicit BitFlagCombinationOfImpl(absl::Span<const T> flags)
       : flags_(flags.begin(), flags.end()), all_flags_combo_{} {
     FUZZTEST_INTERNAL_CHECK_PRECONDITION(
         !flags.empty(), "BitFlagCombinationOf requires a non empty list.");
-    // Make sure they are mutually exclusive options, and none are empty.
+    // Make sure they are mutually exclusive metadata, only_shrink and none are
+    // empty.
     for (int i = 0; i < flags.size(); ++i) {
       T v1 = flags[i];
       FUZZTEST_INTERNAL_CHECK_PRECONDITION(
@@ -57,7 +60,8 @@ class BitFlagCombinationOfImpl
     return value_type{};
   }
 
-  void Mutate(value_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(value_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata&, bool only_shrink) {
     T to_switch = flags_[ChooseOffset(flags_.size(), prng)];
 
     if (!only_shrink || BitAnd(val, to_switch) != T{}) {
diff --git a/fuzztest/internal/domains/container_mutation_helpers.h b/fuzztest/internal/domains/container_mutation_helpers.h
index c6c17de7..f17d52fa 100644
--- a/fuzztest/internal/domains/container_mutation_helpers.h
+++ b/fuzztest/internal/domains/container_mutation_helpers.h
@@ -22,7 +22,6 @@
 
 #include "absl/random/bit_gen_ref.h"
 #include "absl/random/distributions.h"
-#include "./fuzztest/internal/coverage.h"
 #include "./fuzztest/internal/table_of_recent_compares.h"
 
 namespace fuzztest::internal {
@@ -205,6 +204,7 @@ bool ApplyDictionaryMutationAndSavePermanentCandidate(
 template <typename ContainerT>
 bool MemoryDictionaryMutation(
     ContainerT& val, absl::BitGenRef prng,
+    const internal::TablesOfRecentCompares* cmp_tables,
     ContainerDictionary<ContainerT>& temporary_dict,
     ContainerDictionary<ContainerT>& manual_dict,
     ContainerDictionary<ContainerT>& permanent_dict,
@@ -214,9 +214,9 @@ bool MemoryDictionaryMutation(
   const bool can_use_manual_dictionary = !manual_dict.IsEmpty();
   const bool can_use_temporary_dictionary = !temporary_dict.IsEmpty();
   const bool can_use_permanent_dictionary = !permanent_dict.IsEmpty();
-  const int dictionary_action_count = 1 + can_use_manual_dictionary +
-                                      can_use_temporary_dictionary +
-                                      can_use_permanent_dictionary;
+  const int dictionary_action_count =
+      can_use_manual_dictionary + can_use_temporary_dictionary +
+      can_use_permanent_dictionary + (cmp_tables == nullptr ? 0 : 1);
   int dictionary_action = absl::Uniform(prng, 0, dictionary_action_count);
   if (can_use_temporary_dictionary && dictionary_action-- == 0) {
     mutated = ApplyDictionaryMutationAndSavePermanentCandidate(
@@ -245,7 +245,7 @@ bool MemoryDictionaryMutation(
   // Pick entries from tables_of_recent_compares(TORC) directly.
   if (dictionary_action-- == 0) {
     auto dictionary_entry = ContainerDictionary<ContainerT>::GetRandomTORCEntry(
-        val, prng, GetExecutionCoverage()->GetTablesOfRecentCompares());
+        val, prng, *cmp_tables);
     if (dictionary_entry.has_value()) {
       mutated = ApplyDictionaryMutationAndSavePermanentCandidate(
           val, *dictionary_entry, prng, permanent_dict_candidate, max_size);
diff --git a/fuzztest/internal/domains/container_of_impl.h b/fuzztest/internal/domains/container_of_impl.h
index 9fe7372b..70ee9383 100644
--- a/fuzztest/internal/domains/container_of_impl.h
+++ b/fuzztest/internal/domains/container_of_impl.h
@@ -31,14 +31,12 @@
 #include "absl/status/status.h"
 #include "absl/strings/str_format.h"
 #include "absl/types/span.h"
-#include "./fuzztest/internal/coverage.h"
 #include "./fuzztest/internal/domains/container_mutation_helpers.h"
 #include "./fuzztest/internal/domains/domain_base.h"
 #include "./fuzztest/internal/logging.h"
 #include "./fuzztest/internal/meta.h"
 #include "./fuzztest/internal/serialization.h"
 #include "./fuzztest/internal/status.h"
-#include "./fuzztest/internal/table_of_recent_compares.h"
 #include "./fuzztest/internal/type_support.h"
 
 namespace fuzztest::internal {
@@ -87,6 +85,8 @@ class ContainerOfImplBase : public domain_implementor::DomainBase<
   using typename ContainerOfImplBase::DomainBase::corpus_type;
   using typename ContainerOfImplBase::DomainBase::value_type;
 
+  using ContainerOfImplBase::DomainBase::Mutate;
+
   // Some container mutation only applies to vector or string types which do
   // not have a custom corpus type.
   static constexpr bool is_vector_or_string =
@@ -112,7 +112,9 @@ class ContainerOfImplBase : public domain_implementor::DomainBase<
   ContainerOfImplBase() = default;
   explicit ContainerOfImplBase(InnerDomainT inner) : inner_(std::move(inner)) {}
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     permanent_dict_candidate_ = std::nullopt;
     FUZZTEST_INTERNAL_CHECK(
         min_size() <= val.size() && val.size() <= max_size(), "Size ",
@@ -123,7 +125,7 @@ class ContainerOfImplBase : public domain_implementor::DomainBase<
     const bool can_change = val.size() != 0;
     const bool can_use_memory_dict = !only_shrink &&
                                      container_has_memory_dict && can_change &&
-                                     GetExecutionCoverage() != nullptr;
+                                     metadata.cmp_tables != nullptr;
 
     const int action_count =
         can_shrink + can_grow + can_change + can_use_memory_dict;
@@ -162,12 +164,12 @@ class ContainerOfImplBase : public domain_implementor::DomainBase<
           auto it_start = std::next(val.begin(), change_offset);
           auto it_end = std::next(it_start, changes);
           for (; it_start != it_end; it_start = std::next(it_start)) {
-            Self().MutateElement(val, prng, it_start, only_shrink);
+            Self().MutateElement(val, prng, metadata, only_shrink, it_start);
           }
           return;
         }
-        Self().MutateElement(
-            val, prng, ChoosePosition(val, IncludeEnd::kNo, prng), only_shrink);
+        Self().MutateElement(val, prng, metadata, only_shrink,
+                             ChoosePosition(val, IncludeEnd::kNo, prng));
         return;
       }
     }
@@ -175,13 +177,12 @@ class ContainerOfImplBase : public domain_implementor::DomainBase<
       if (can_use_memory_dict) {
         if (action-- == 0) {
           bool mutated = MemoryDictionaryMutation(
-              val, prng, temporary_dict_, GetManualDict(), permanent_dict_,
-              permanent_dict_candidate_, max_size());
+              val, prng, metadata.cmp_tables, temporary_dict_, GetManualDict(),
+              permanent_dict_, permanent_dict_candidate_, max_size());
           // If dict failed, fall back to changing an element.
           if (!mutated) {
-            Self().MutateElement(val, prng,
-                                 ChoosePosition(val, IncludeEnd::kNo, prng),
-                                 only_shrink);
+            Self().MutateElement(val, prng, metadata, only_shrink,
+                                 ChoosePosition(val, IncludeEnd::kNo, prng));
           }
           return;
         }
@@ -189,16 +190,17 @@ class ContainerOfImplBase : public domain_implementor::DomainBase<
     }
   }
 
-  void UpdateMemoryDictionary(const corpus_type& val) {
+  void UpdateMemoryDictionary(
+      const corpus_type& val,
+      domain_implementor::ConstCmpTablesPtr cmp_tables) {
     // TODO(JunyangShao): Implement dictionary propagation to container
     // elements. For now the propagation stops in container domains.
     // Because all elements share an `inner_` and will share
     // a dictionary if we propagate it, which makes the dictionary
     // not efficient.
     if constexpr (container_has_memory_dict) {
-      if (GetExecutionCoverage() != nullptr) {
-        temporary_dict_.MatchEntriesFromTableOfRecentCompares(
-            val, GetExecutionCoverage()->GetTablesOfRecentCompares());
+      if (cmp_tables != nullptr) {
+        temporary_dict_.MatchEntriesFromTableOfRecentCompares(val, *cmp_tables);
         if (permanent_dict_candidate_.has_value() &&
             permanent_dict_.Size() < kPermanentDictMaxSize) {
           permanent_dict_.AddEntry(std::move(*permanent_dict_candidate_));
@@ -494,7 +496,8 @@ Please verify that the inner domain can provide enough values.
 
   // Try to mutate the element in `it`.
   void MutateElement(corpus_type& val, absl::BitGenRef prng,
-                     typename corpus_type::iterator it, bool only_shrink) {
+                     const domain_implementor::MutationMetadata& metadata,
+                     bool only_shrink, typename corpus_type::iterator it) {
     size_t failures_allowed = 100;
     // Try a few times to mutate the element.
     // If the mutation reduces the number of elements in the container it means
@@ -510,7 +513,7 @@ Please verify that the inner domain can provide enough values.
 
     while (failures_allowed > 0) {
       auto new_element = original_element_list.front();
-      this->inner_.Mutate(new_element, prng, only_shrink);
+      this->inner_.Mutate(new_element, prng, metadata, only_shrink);
       if (real_value.insert(this->inner_.GetValue(new_element)).second) {
         val.push_back(std::move(new_element));
         return;
@@ -553,13 +556,14 @@ class SequenceContainerOfImpl
     return total_weight;
   }
 
-  uint64_t MutateSelectedField(corpus_type& val, absl::BitGenRef prng,
-                               bool only_shrink,
-                               uint64_t selected_field_index) {
+  uint64_t MutateSelectedField(
+      corpus_type& val, absl::BitGenRef prng,
+      const domain_implementor::MutationMetadata& metadata, bool only_shrink,
+      uint64_t selected_field_index) {
     uint64_t field_counter = 0;
     for (auto& i : val) {
       field_counter += this->inner_.MutateSelectedField(
-          i, prng, only_shrink, selected_field_index - field_counter);
+          i, prng, metadata, only_shrink, selected_field_index - field_counter);
       if (field_counter >= selected_field_index) break;
     }
     return field_counter;
@@ -574,8 +578,9 @@ class SequenceContainerOfImpl
   }
 
   void MutateElement(corpus_type&, absl::BitGenRef prng,
-                     typename corpus_type::iterator it, bool only_shrink) {
-    this->inner_.Mutate(*it, prng, only_shrink);
+                     const domain_implementor::MutationMetadata& metadata,
+                     bool only_shrink, typename corpus_type::iterator it) {
+    this->inner_.Mutate(*it, prng, metadata, only_shrink);
   }
 };
 
diff --git a/fuzztest/internal/domains/domain.h b/fuzztest/internal/domains/domain.h
index 8d0ad2fa..6faa9fc8 100644
--- a/fuzztest/internal/domains/domain.h
+++ b/fuzztest/internal/domains/domain.h
@@ -31,6 +31,7 @@
 #include "./fuzztest/internal/domains/domain_type_erasure.h"  // IWYU pragma: export
 #include "./fuzztest/internal/printer.h"
 #include "./fuzztest/internal/serialization.h"
+#include "./fuzztest/internal/table_of_recent_compares.h"
 
 namespace fuzztest {
 namespace internal {
@@ -156,13 +157,23 @@ class Domain {
 
   // Mutate() makes a relatively small modification on `val` of `corpus_type`.
   //
-  // Used during coverage-guided fuzzing. When `only_shrink` is enabled, the
-  // mutated value is always "simpler" (e.g., smaller). This is used for input
-  // minimization ("shrinking").
+  // Used during coverage-guided fuzzing. When `only_shrink` is true,
+  // the mutated value is always "simpler" (e.g., smaller). This is used for
+  // input minimization ("shrinking").
   //
   // ENSURES: That the mutated value is not the same as the original.
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
-    return inner_->UntypedMutate(val, prng, only_shrink);
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
+    return inner_->UntypedMutate(val, prng, metadata, only_shrink);
+  }
+
+  // Mutates `corpus_value` using `prng`, `only_shirnk` and the default mutation
+  // metadata. This is a temporary wrapper that redirects the call to the real
+  // interface with an explicit argument for metadata.
+  void Mutate(corpus_type& corpus_value, absl::BitGenRef prng,
+              bool only_shrink) {
+    return Mutate(corpus_value, prng, {}, only_shrink);
   }
 
   // The methods below are responsible for transforming between the above
@@ -232,8 +243,10 @@ class Domain {
   //
   // TODO(b/303324603): Using an extension mechanism, expose this method in
   // the interface only for user value types `T` for which it makes sense.
-  void UpdateMemoryDictionary(const corpus_type& corpus_value) {
-    return inner_->UntypedUpdateMemoryDictionary(corpus_value);
+  void UpdateMemoryDictionary(
+      const corpus_type& corpus_value,
+      const internal::TablesOfRecentCompares* cmp_tables) {
+    return inner_->UntypedUpdateMemoryDictionary(corpus_value, cmp_tables);
   }
 
   // Return the field counts of `corpus_value` if `corpus_value` is
@@ -251,11 +264,12 @@ class Domain {
   //
   // TODO(b/303324603): Using an extension mechanism, expose this method in
   // the interface only for user value types `T` for which it makes sense.
-  uint64_t MutateSelectedField(corpus_type& corpus_value, absl::BitGenRef prng,
-                               bool only_shrink,
-                               uint64_t selected_field_index) {
-    return inner_->UntypedMutateSelectedField(corpus_value, prng, only_shrink,
-                                              selected_field_index);
+  uint64_t MutateSelectedField(
+      corpus_type& corpus_value, absl::BitGenRef prng,
+      const domain_implementor::MutationMetadata& metadata, bool only_shrink,
+      uint64_t selected_field_index) {
+    return inner_->UntypedMutateSelectedField(
+        corpus_value, prng, metadata, only_shrink, selected_field_index);
   }
 
  private:
@@ -302,9 +316,15 @@ class UntypedDomain {
 
   corpus_type Init(absl::BitGenRef prng) { return inner_->UntypedInit(prng); }
 
+  void Mutate(corpus_type& corpus_value, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
+    return inner_->UntypedMutate(corpus_value, prng, metadata, only_shrink);
+  }
+
   void Mutate(corpus_type& corpus_value, absl::BitGenRef prng,
               bool only_shrink) {
-    return inner_->UntypedMutate(corpus_value, prng, only_shrink);
+    return Mutate(corpus_value, prng, {}, only_shrink);
   }
 
   value_type GetValue(const corpus_type& corpus_value) const {
@@ -325,8 +345,10 @@ class UntypedDomain {
 
   auto GetPrinter() const { return internal::GenericPrinter{*inner_}; }
 
-  void UpdateMemoryDictionary(const corpus_type& corpus_value) {
-    return inner_->UntypedUpdateMemoryDictionary(corpus_value);
+  void UpdateMemoryDictionary(
+      const corpus_type& corpus_value,
+      domain_implementor::ConstCmpTablesPtr cmp_tables) {
+    return inner_->UntypedUpdateMemoryDictionary(corpus_value, cmp_tables);
   }
 
  private:
diff --git a/fuzztest/internal/domains/domain_base.h b/fuzztest/internal/domains/domain_base.h
index 393bfe85..743a3abd 100644
--- a/fuzztest/internal/domains/domain_base.h
+++ b/fuzztest/internal/domains/domain_base.h
@@ -31,10 +31,10 @@
 #include "absl/status/status.h"
 #include "absl/strings/str_format.h"
 #include "./fuzztest/internal/domains/domain_type_erasure.h"
+#include "./fuzztest/internal/domains/mutation_metadata.h"  // IWYU pragma: export
 #include "./fuzztest/internal/meta.h"
 #include "./fuzztest/internal/printer.h"
 #include "./fuzztest/internal/serialization.h"
-#include "./fuzztest/internal/table_of_recent_compares.h"
 #include "./fuzztest/internal/type_support.h"
 
 namespace fuzztest::internal {
@@ -73,7 +73,8 @@ namespace fuzztest::domain_implementor {
 //   may first call `MaybeGetRandomSeed()` and return its non-nullopt result.
 //   TODO(b/303324603): Move the call to `MaybeGetRandomSeed()` to a wrapper.
 //
-// - void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink)
+// - void Mutate(corpus_type& val, absl::BitGenRef prng,
+//               const MutationMetadata& metadata, bool only_shrink)
 //
 //   The method that mutates the corpus value.
 //
@@ -130,6 +131,15 @@ class DomainBase {
     }
   }
 
+  // Mutates `corpus_value` using `prng`, `only_shirnk` and the default mutation
+  // metadata. This is a temporary wrapper that redirects the call to the real
+  // interface with an explicit argument for metadata.
+  void Mutate(corpus_type& corpus_value, absl::BitGenRef prng,
+              bool only_shrink) {
+    return derived().Mutate(corpus_value, prng, MutationMetadata{},
+                            only_shrink);
+  }
+
   // Returns a random user value from the domain. In general, doesn't provide
   // guarantees on the distribution of the returned values.
   //
@@ -165,11 +175,12 @@ class DomainBase {
     return internal::IRObject::FromCorpus(v);
   }
 
-  void UpdateMemoryDictionary(const CorpusType& val) {}
+  void UpdateMemoryDictionary(const CorpusType& val, ConstCmpTablesPtr) {}
 
   uint64_t CountNumberOfFields(const CorpusType&) { return 0; }
 
-  uint64_t MutateSelectedField(CorpusType&, absl::BitGenRef, bool, uint64_t) {
+  uint64_t MutateSelectedField(CorpusType&, absl::BitGenRef,
+                               const MutationMetadata&, bool, uint64_t) {
     return 0;
   }
 
@@ -240,7 +251,8 @@ class DomainBase {
     // probability.
     constexpr int kMaxMutations = 1000;
     for (int i = absl::Uniform(prng, 0, kMaxMutations); i > 0; --i) {
-      derived().Mutate(corpus_val, prng, /*only_shrink=*/false);
+      derived().Mutate(corpus_val, prng, MutationMetadata{},
+                       /*only_shrink=*/false);
     }
     return corpus_val;
   }
diff --git a/fuzztest/internal/domains/domain_type_erasure.h b/fuzztest/internal/domains/domain_type_erasure.h
index c5b5b2a3..c2dfb83c 100644
--- a/fuzztest/internal/domains/domain_type_erasure.h
+++ b/fuzztest/internal/domains/domain_type_erasure.h
@@ -34,6 +34,7 @@
 #include "absl/status/status.h"
 #include "absl/strings/string_view.h"
 #include "./fuzztest/internal/any.h"
+#include "./fuzztest/internal/domains/mutation_metadata.h"
 #include "./fuzztest/internal/logging.h"
 #include "./fuzztest/internal/meta.h"
 #include "./fuzztest/internal/printer.h"
@@ -56,10 +57,13 @@ class UntypedDomainConcept {
 
   virtual std::unique_ptr<UntypedDomainConcept> UntypedClone() const = 0;
   virtual GenericDomainCorpusType UntypedInit(absl::BitGenRef) = 0;
-  virtual void UntypedMutate(GenericDomainCorpusType& val, absl::BitGenRef prng,
-                             bool only_shrink) = 0;
+  virtual void UntypedMutate(
+      GenericDomainCorpusType& val, absl::BitGenRef prng,
+      const domain_implementor::MutationMetadata& metadata,
+      bool only_shrink) = 0;
   virtual void UntypedUpdateMemoryDictionary(
-      const GenericDomainCorpusType& val) = 0;
+      const GenericDomainCorpusType& val,
+      domain_implementor::ConstCmpTablesPtr cmp_tables) = 0;
   virtual std::optional<GenericDomainCorpusType> UntypedParseCorpus(
       const IRObject& obj) const = 0;
   virtual absl::Status UntypedValidateCorpusValue(
@@ -68,9 +72,9 @@ class UntypedDomainConcept {
       const GenericDomainCorpusType& v) const = 0;
   virtual uint64_t UntypedCountNumberOfFields(
       const GenericDomainCorpusType&) = 0;
-  virtual uint64_t UntypedMutateSelectedField(GenericDomainCorpusType&,
-                                              absl::BitGenRef, bool,
-                                              uint64_t) = 0;
+  virtual uint64_t UntypedMutateSelectedField(
+      GenericDomainCorpusType&, absl::BitGenRef,
+      const domain_implementor::MutationMetadata&, bool, uint64_t) = 0;
   virtual GenericDomainValueType UntypedGetValue(
       const GenericDomainCorpusType& v) const = 0;
   virtual void UntypedPrintCorpusValue(
@@ -135,12 +139,15 @@ class DomainModel final : public TypedDomainConcept<value_type_t<D>> {
   }
 
   void UntypedMutate(GenericDomainCorpusType& val, absl::BitGenRef prng,
+                     const domain_implementor::MutationMetadata& metadata,
                      bool only_shrink) final {
-    domain_.Mutate(val.GetAs<CorpusType>(), prng, only_shrink);
+    domain_.Mutate(val.GetAs<CorpusType>(), prng, metadata, only_shrink);
   }
 
-  void UntypedUpdateMemoryDictionary(const GenericDomainCorpusType& val) final {
-    domain_.UpdateMemoryDictionary(val.GetAs<CorpusType>());
+  void UntypedUpdateMemoryDictionary(
+      const GenericDomainCorpusType& val,
+      domain_implementor::ConstCmpTablesPtr cmp_tables) final {
+    domain_.UpdateMemoryDictionary(val.GetAs<CorpusType>(), cmp_tables);
   }
 
   ValueType TypedGetRandomValue(absl::BitGenRef prng) final {
@@ -185,11 +192,12 @@ class DomainModel final : public TypedDomainConcept<value_type_t<D>> {
     return domain_.CountNumberOfFields(v.GetAs<CorpusType>());
   }
 
-  uint64_t UntypedMutateSelectedField(GenericDomainCorpusType& v,
-                                      absl::BitGenRef prng, bool only_shrink,
-                                      uint64_t selected_field_index) final {
-    return domain_.MutateSelectedField(v.GetAs<CorpusType>(), prng, only_shrink,
-                                       selected_field_index);
+  uint64_t UntypedMutateSelectedField(
+      GenericDomainCorpusType& v, absl::BitGenRef prng,
+      const domain_implementor::MutationMetadata& metadata, bool only_shrink,
+      uint64_t selected_field_index) final {
+    return domain_.MutateSelectedField(v.GetAs<CorpusType>(), prng, metadata,
+                                       only_shrink, selected_field_index);
   }
 
   void UntypedPrintCorpusValue(const GenericDomainCorpusType& val,
diff --git a/fuzztest/internal/domains/element_of_impl.h b/fuzztest/internal/domains/element_of_impl.h
index 5ab31485..274b1e99 100644
--- a/fuzztest/internal/domains/element_of_impl.h
+++ b/fuzztest/internal/domains/element_of_impl.h
@@ -41,6 +41,8 @@ class ElementOfImpl
   using typename ElementOfImpl::DomainBase::corpus_type;
   using typename ElementOfImpl::DomainBase::value_type;
 
+  using ElementOfImpl::DomainBase::Mutate;
+
   explicit ElementOfImpl(std::vector<T> values) : values_(values) {
     FUZZTEST_INTERNAL_CHECK_PRECONDITION(
         !values.empty(), "ElementOf requires a non empty list.");
@@ -51,7 +53,8 @@ class ElementOfImpl
     return corpus_type{absl::Uniform<size_t>(prng, 0, values_.size())};
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata&, bool only_shrink) {
     if (values_.size() <= 1) return;
     if (only_shrink) {
       size_t index = static_cast<size_t>(val);
diff --git a/fuzztest/internal/domains/filter_impl.h b/fuzztest/internal/domains/filter_impl.h
index 346537cf..6b776200 100644
--- a/fuzztest/internal/domains/filter_impl.h
+++ b/fuzztest/internal/domains/filter_impl.h
@@ -37,6 +37,8 @@ class FilterImpl
   using typename FilterImpl::DomainBase::corpus_type;
   using typename FilterImpl::DomainBase::value_type;
 
+  using FilterImpl::DomainBase::Mutate;
+
   FilterImpl() = default;
   explicit FilterImpl(std::function<bool(const T&)> predicate, Domain<T> inner)
       : predicate_(std::move(predicate)), inner_(std::move(inner)) {}
@@ -49,10 +51,12 @@ class FilterImpl
     }
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     corpus_type original_val = val;
     while (true) {
-      inner_.Mutate(val, prng, only_shrink);
+      inner_.Mutate(val, prng, metadata, only_shrink);
       if (RunFilter(val)) return;
       val = original_val;
     }
diff --git a/fuzztest/internal/domains/flat_map_impl.h b/fuzztest/internal/domains/flat_map_impl.h
index 49cbc2b0..6d90abdf 100644
--- a/fuzztest/internal/domains/flat_map_impl.h
+++ b/fuzztest/internal/domains/flat_map_impl.h
@@ -60,6 +60,8 @@ class FlatMapImpl
   using typename FlatMapImpl::DomainBase::corpus_type;
   using typename FlatMapImpl::DomainBase::value_type;
 
+  using FlatMapImpl::DomainBase::Mutate;
+
   FlatMapImpl() = default;
   explicit FlatMapImpl(FlatMapper flat_mapper, InputDomain... input_domains)
       : flat_mapper_(std::move(flat_mapper)),
@@ -77,7 +79,9 @@ class FlatMapImpl
                           input_corpus);
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     // There is no way to tell whether the current output corpus value is
     // consistent with a new output domain generated by mutated inputs, so
     // mutating the inputs forces re-initialization of the output domain. This
@@ -88,7 +92,7 @@ class FlatMapImpl
       ApplyIndex<kNumInputValues>([&](auto... I) {
         // The first field of `val` is the output corpus value, so skip it.
         (std::get<I>(input_domains_)
-             .Mutate(std::get<I + 1>(val), prng, only_shrink),
+             .Mutate(std::get<I + 1>(val), prng, metadata, only_shrink),
          ...);
       });
       std::get<0>(val) = GetOutputDomain(val).Init(prng);
@@ -99,7 +103,7 @@ class FlatMapImpl
     // convenience, not correctness. For example, `Filter` won't automatically
     // find when something is too restrictive.
     // TODO(b/246423623): Support stateful domains.
-    GetOutputDomain(val).Mutate(std::get<0>(val), prng, only_shrink);
+    GetOutputDomain(val).Mutate(std::get<0>(val), prng, metadata, only_shrink);
   }
 
   value_type GetValue(const corpus_type& v) const {
diff --git a/fuzztest/internal/domains/in_grammar_impl.h b/fuzztest/internal/domains/in_grammar_impl.h
index fc94a5a6..cdb15e23 100644
--- a/fuzztest/internal/domains/in_grammar_impl.h
+++ b/fuzztest/internal/domains/in_grammar_impl.h
@@ -104,7 +104,8 @@ class StringLiteralDomain {
     return ASTNode{id, std::monostate()};
   }
 
-  static void Mutate(ASTNode& val, absl::BitGenRef prng, bool only_shrink) {}
+  static void Mutate(ASTNode& val, absl::BitGenRef prng,
+                     const domain_implementor::MutationMetadata&, bool) {}
 
   static ASTTypeId TypeId() { return id; }
 
@@ -147,8 +148,11 @@ class RegexLiteralDomain {
     return ASTNode{id, GetInnerRegexpDomain().Init(prng)};
   }
 
-  static void Mutate(ASTNode& val, absl::BitGenRef prng, bool only_shrink) {
-    GetInnerRegexpDomain().Mutate(std::get<1>(val.children), prng, only_shrink);
+  static void Mutate(ASTNode& val, absl::BitGenRef prng,
+                     const domain_implementor::MutationMetadata& metadata,
+                     bool only_shrink) {
+    GetInnerRegexpDomain().Mutate(std::get<1>(val.children), prng, metadata,
+                                  only_shrink);
   }
 
   static ASTTypeId TypeId() { return id; }
@@ -233,7 +237,9 @@ class VectorDomain {
 
   static ASTTypeId TypeId() { return id; }
 
-  static void Mutate(ASTNode& val, absl::BitGenRef prng, bool only_shrink) {
+  static void Mutate(ASTNode& val, absl::BitGenRef prng,
+                     const domain_implementor::MutationMetadata& metadata,
+                     bool only_shrink) {
     FUZZTEST_INTERNAL_CHECK(val.children.index() == 2, "Not a vector!");
     std::vector<ASTNode>& elements = std::get<2>(val.children);
     if (only_shrink) {
@@ -253,14 +259,14 @@ class VectorDomain {
     } else if (!can_change_element_num) {
       ElementT::Mutate(
           elements[absl::Uniform<size_t>(prng, 0, elements.size())], prng,
-          only_shrink);
+          metadata, only_shrink);
     } else {
       if (absl::Bernoulli(prng, 0.5)) {
         ChangeElementNum(elements, prng);
       } else {
         ElementT::Mutate(
             elements[absl::Uniform<size_t>(prng, 0, elements.size())], prng,
-            only_shrink);
+            metadata, only_shrink);
       }
     }
   }
@@ -323,7 +329,7 @@ class VectorDomain {
     if (!can_remove_element) {
       // Cannot remove elements, let's shrink them.
       ElementT::Mutate(*ChoosePosition(elements, IncludeEnd::kNo, prng), prng,
-                       true);
+                       {}, /*only_shrink=*/true);
     } else if (!can_shrink_element) {
       // Cannot shrink elements, let's remove one.
       elements.erase(ChoosePosition(elements, IncludeEnd::kNo, prng));
@@ -334,7 +340,7 @@ class VectorDomain {
 
       } else {
         ElementT::Mutate(*ChoosePosition(elements, IncludeEnd::kNo, prng), prng,
-                         true);
+                         {}, /*only_shrink=*/true);
       }
     }
   }
@@ -383,7 +389,9 @@ class TupleDomain {
                 generation_budget / static_cast<int>(sizeof...(ElementT)))...}};
   }
 
-  static void Mutate(ASTNode& val, absl::BitGenRef prng, bool only_shrink) {
+  static void Mutate(ASTNode& val, absl::BitGenRef prng,
+                     const domain_implementor::MutationMetadata& metadata,
+                     bool only_shrink) {
     FUZZTEST_INTERNAL_CHECK(
         val.children.index() == 2 &&
             std::get<2>(val.children).size() == sizeof...(ElementT),
@@ -404,7 +412,7 @@ class TupleDomain {
     int choice = mutables[absl::Uniform<int>(prng, 0, mutables.size())];
     ApplyIndex<sizeof...(ElementT)>([&](auto... I) {
       ((choice == I ? (ElementT::Mutate(std::get<2>(val.children)[I], prng,
-                                        only_shrink))
+                                        metadata, only_shrink))
                     : (void)0),
        ...);
     });
@@ -492,7 +500,9 @@ class VariantDomain {
     return result;
   }
 
-  static void Mutate(ASTNode& val, absl::BitGenRef prng, bool only_shrink) {
+  static void Mutate(ASTNode& val, absl::BitGenRef prng,
+                     const domain_implementor::MutationMetadata& metadata,
+                     bool only_shrink) {
     constexpr bool has_alternative = sizeof...(ElementT) > 1;
     ASTNode current_value = std::get<2>(val.children).front();
     ASTTypeId current_value_id = current_value.type_id;
@@ -507,7 +517,7 @@ class VariantDomain {
                             "Impossible at" + std::to_string(id));
     if (only_shrink) {
       if (is_current_value_mutable) {
-        MutateCurrentValue(val, prng, only_shrink);
+        MutateCurrentValue(val, prng, metadata, only_shrink);
       }
       return;
     }
@@ -515,10 +525,10 @@ class VariantDomain {
     if (!is_current_value_mutable) {
       SwitchToAlternative(val, prng);
     } else if (!has_alternative) {
-      MutateCurrentValue(val, prng, only_shrink);
+      MutateCurrentValue(val, prng, metadata, only_shrink);
     } else {
       if (absl::Bernoulli(prng, 0.5)) {
-        MutateCurrentValue(val, prng, only_shrink);
+        MutateCurrentValue(val, prng, metadata, only_shrink);
       } else {
         SwitchToAlternative(val, prng);
       }
@@ -594,11 +604,12 @@ class VariantDomain {
   }
 
  private:
-  static void MutateCurrentValue(ASTNode& val, absl::BitGenRef prng,
-                                 bool only_shrink) {
+  static void MutateCurrentValue(
+      ASTNode& val, absl::BitGenRef prng,
+      const domain_implementor::MutationMetadata& metadata, bool only_shrink) {
     ASTNode& current_value = std::get<2>(val.children).front();
     ((ElementT::TypeId() == current_value.type_id
-          ? (ElementT::Mutate(current_value, prng, only_shrink))
+          ? (ElementT::Mutate(current_value, prng, metadata, only_shrink))
           : (void)0),
      ...);
   }
@@ -640,17 +651,21 @@ class InGrammarImpl
   using typename InGrammarImpl::DomainBase::corpus_type;
   using typename InGrammarImpl::DomainBase::value_type;
 
+  using InGrammarImpl::DomainBase::Mutate;
+
   ASTNode Init(absl::BitGenRef prng) {
     if (auto seed = this->MaybeGetRandomSeed(prng)) return *seed;
     return TopDomain::Init(prng);
   }
 
-  void Mutate(ASTNode& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(ASTNode& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     if (only_shrink && absl::Bernoulli(prng, 0.5) &&
         ShrinkByReplaceWithSubElementOfSameType(val, prng)) {
       return;
     }
-    TopDomain::Mutate(val, prng, only_shrink);
+    TopDomain::Mutate(val, prng, metadata, only_shrink);
   }
 
   auto GetPrinter() const { return StringPrinter{}; }
diff --git a/fuzztest/internal/domains/in_range_impl.h b/fuzztest/internal/domains/in_range_impl.h
index c0d52a76..fc7a04ef 100644
--- a/fuzztest/internal/domains/in_range_impl.h
+++ b/fuzztest/internal/domains/in_range_impl.h
@@ -29,13 +29,11 @@
 #include "absl/status/status.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
-#include "./fuzztest/internal/coverage.h"
 #include "./fuzztest/internal/domains/domain_base.h"
 #include "./fuzztest/internal/domains/special_values.h"
 #include "./fuzztest/internal/domains/value_mutation_helpers.h"
 #include "./fuzztest/internal/logging.h"
 #include "./fuzztest/internal/printer.h"
-#include "./fuzztest/internal/table_of_recent_compares.h"
 #include "./fuzztest/internal/type_support.h"
 
 namespace fuzztest::internal {
@@ -45,6 +43,8 @@ class InRangeImpl : public domain_implementor::DomainBase<InRangeImpl<T>> {
  public:
   using typename InRangeImpl::DomainBase::value_type;
 
+  using InRangeImpl::DomainBase::Mutate;
+
   constexpr static bool T_is_integer = std::numeric_limits<T>::is_integer;
   constexpr static bool T_is_signed = std::is_signed<T>::value;
   constexpr static bool T_is_memory_dictionary_compatible =
@@ -106,7 +106,9 @@ class InRangeImpl : public domain_implementor::DomainBase<InRangeImpl<T>> {
     });
   }
 
-  void Mutate(value_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(value_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     if (min_ == max_) {
       val = min_;
       return;
@@ -146,9 +148,9 @@ class InRangeImpl : public domain_implementor::DomainBase<InRangeImpl<T>> {
               val = absl::Uniform(absl::IntervalClosedClosed, prng, min_, max_);
             }
           } else {
-            RandomWalkOrUniformOrDict<5>(prng, val, min_, max_, temporary_dict_,
-                                         permanent_dict_,
-                                         permanent_dict_candidate_);
+            RandomWalkOrUniformOrDict<5>(
+                prng, val, min_, max_, metadata.cmp_tables, temporary_dict_,
+                permanent_dict_, permanent_dict_candidate_);
           }
         } else {
           if (absl::Bernoulli(prng, 0.25)) {
@@ -157,14 +159,14 @@ class InRangeImpl : public domain_implementor::DomainBase<InRangeImpl<T>> {
               val = absl::Uniform(absl::IntervalClosedClosed, prng, min_, max_);
             }
           } else {
-            RandomWalkOrUniformOrDict<5>(prng, val, min_, max_, temporary_dict_,
-                                         permanent_dict_,
-                                         permanent_dict_candidate_);
+            RandomWalkOrUniformOrDict<5>(
+                prng, val, min_, max_, metadata.cmp_tables, temporary_dict_,
+                permanent_dict_, permanent_dict_candidate_);
           }
         }
       } else {
-        RandomWalkOrUniformOrDict<5>(prng, val, min_, max_, temporary_dict_,
-                                     permanent_dict_,
+        RandomWalkOrUniformOrDict<5>(prng, val, min_, max_, metadata.cmp_tables,
+                                     temporary_dict_, permanent_dict_,
                                      permanent_dict_candidate_);
       }
     } while (val == prev);  // Make sure Mutate really mutates.
@@ -198,12 +200,12 @@ class InRangeImpl : public domain_implementor::DomainBase<InRangeImpl<T>> {
     }
   }
 
-  void UpdateMemoryDictionary(const value_type& val) {
+  void UpdateMemoryDictionary(
+      const value_type& val, domain_implementor::ConstCmpTablesPtr cmp_tables) {
     if constexpr (T_is_memory_dictionary_compatible) {
-      if (GetExecutionCoverage() != nullptr) {
-        temporary_dict_.MatchEntriesFromTableOfRecentCompares(
-            val, GetExecutionCoverage()->GetTablesOfRecentCompares(), min_,
-            max_);
+      if (cmp_tables != nullptr) {
+        temporary_dict_.MatchEntriesFromTableOfRecentCompares(val, *cmp_tables,
+                                                              min_, max_);
         if (permanent_dict_candidate_.has_value() &&
             permanent_dict_.Size() < kPermanentDictMaxSize) {
           permanent_dict_.AddEntry(std::move(*permanent_dict_candidate_));
diff --git a/fuzztest/internal/domains/in_regexp_impl.h b/fuzztest/internal/domains/in_regexp_impl.h
index 108e1837..9d02cb34 100644
--- a/fuzztest/internal/domains/in_regexp_impl.h
+++ b/fuzztest/internal/domains/in_regexp_impl.h
@@ -44,6 +44,8 @@ class InRegexpImpl
     : public domain_implementor::DomainBase<InRegexpImpl, std::string,
                                             DFAPath> {
  public:
+  using InRegexpImpl::DomainBase::Mutate;
+
   explicit InRegexpImpl(std::string_view regex_str)
       : regex_str_(regex_str), dfa_(RegexpDFA::Create(regex_str_)) {}
 
@@ -59,7 +61,8 @@ class InRegexpImpl
   // Strategy: Parse the input string into a path in the DFA. Pick a node in the
   // path and random walk from the node until we reach an end state or go back
   // to the original path.
-  void Mutate(DFAPath& path, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(DFAPath& path, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata&, bool only_shrink) {
     if (only_shrink) {
       // Fast path to remove loop.
       if (absl::Bernoulli(prng, 0.5)) {
diff --git a/fuzztest/internal/domains/map_impl.h b/fuzztest/internal/domains/map_impl.h
index f4a57e26..4d367b54 100644
--- a/fuzztest/internal/domains/map_impl.h
+++ b/fuzztest/internal/domains/map_impl.h
@@ -42,6 +42,8 @@ class MapImpl
   using typename MapImpl::DomainBase::corpus_type;
   using typename MapImpl::DomainBase::value_type;
 
+  using MapImpl::DomainBase::Mutate;
+
   MapImpl() = default;
   explicit MapImpl(Mapper mapper, Inner... inner)
       : mapper_(std::move(mapper)), inner_(std::move(inner)...) {}
@@ -58,9 +60,13 @@ class MapImpl
         inner_);
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     return ApplyIndex<sizeof...(Inner)>([&](auto... I) {
-      (std::get<I>(inner_).Mutate(std::get<I>(val), prng, only_shrink), ...);
+      (std::get<I>(inner_).Mutate(std::get<I>(val), prng, metadata,
+                                  only_shrink),
+       ...);
     });
   }
 
@@ -117,6 +123,8 @@ class ReversibleMapImpl
   using typename ReversibleMapImpl::DomainBase::corpus_type;
   using typename ReversibleMapImpl::DomainBase::value_type;
 
+  using ReversibleMapImpl::DomainBase::Mutate;
+
   static_assert(
       std::is_invocable_v<InvMapper, const value_type&> &&
       std::is_same_v<std::invoke_result_t<InvMapper, const value_type&>,
@@ -135,9 +143,13 @@ class ReversibleMapImpl
         inner_);
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     return ApplyIndex<sizeof...(Inner)>([&](auto... I) {
-      (std::get<I>(inner_).Mutate(std::get<I>(val), prng, only_shrink), ...);
+      (std::get<I>(inner_).Mutate(std::get<I>(val), prng, metadata,
+                                  only_shrink),
+       ...);
     });
   }
 
diff --git a/fuzztest/internal/domains/mutation_metadata.h b/fuzztest/internal/domains/mutation_metadata.h
new file mode 100644
index 00000000..e329d970
--- /dev/null
+++ b/fuzztest/internal/domains/mutation_metadata.h
@@ -0,0 +1,33 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef FUZZTEST_FUZZTEST_INTERNAL_DOMAINS_MUTATION_METADATA_H_
+#define FUZZTEST_FUZZTEST_INTERNAL_DOMAINS_MUTATION_METADATA_H_
+
+#include "./fuzztest/internal/table_of_recent_compares.h"
+
+namespace fuzztest::domain_implementor {
+
+// Opaque pointer to comparison tables used by builtin domains, imported here
+// for domain implementors who do not need the internal header.
+using ConstCmpTablesPtr = const internal::TablesOfRecentCompares*;
+
+// A struct holding metadata for domain mutation.
+struct MutationMetadata {
+  ConstCmpTablesPtr cmp_tables = nullptr;
+};
+
+}  //  namespace fuzztest::domain_implementor
+
+#endif  // FUZZTEST_FUZZTEST_INTERNAL_DOMAINS_MUTATION_METADATA_H_
diff --git a/fuzztest/internal/domains/one_of_impl.h b/fuzztest/internal/domains/one_of_impl.h
index aeb72fdf..d95ac3bf 100644
--- a/fuzztest/internal/domains/one_of_impl.h
+++ b/fuzztest/internal/domains/one_of_impl.h
@@ -42,6 +42,8 @@ class OneOfImpl
   using typename OneOfImpl::DomainBase::corpus_type;
   using typename OneOfImpl::DomainBase::value_type;
 
+  using OneOfImpl::DomainBase::Mutate;
+
   // All value_types of inner domains must be the same. (Though note that they
   // can have different corpus_types!)
   static_assert(
@@ -61,7 +63,9 @@ class OneOfImpl
         });
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     // Switch to another domain 1% of the time when not reducing.
     if (kNumDomains > 1 && !only_shrink && absl::Bernoulli(prng, 0.01)) {
       // Choose a different index.
@@ -76,7 +80,7 @@ class OneOfImpl
     } else {
       Switch<kNumDomains>(val.index(), [&](auto I) {
         auto& domain = std::get<I>(domains_);
-        domain.Mutate(std::get<I>(val), prng, only_shrink);
+        domain.Mutate(std::get<I>(val), prng, metadata, only_shrink);
       });
     }
   }
diff --git a/fuzztest/internal/domains/optional_of_impl.h b/fuzztest/internal/domains/optional_of_impl.h
index 28dc2bef..7b6f728b 100644
--- a/fuzztest/internal/domains/optional_of_impl.h
+++ b/fuzztest/internal/domains/optional_of_impl.h
@@ -53,6 +53,8 @@ class OptionalOfImpl
   using typename OptionalOfImpl::DomainBase::corpus_type;
   using typename OptionalOfImpl::DomainBase::value_type;
 
+  using OptionalOfImpl::DomainBase::Mutate;
+
   static_assert(Requires<T>([](auto x) -> std::void_t<decltype(!x, *x),
                                                       typename T::value_type> {
                 }),
@@ -74,7 +76,9 @@ class OptionalOfImpl
     }
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     if (policy_ == OptionalPolicy::kAlwaysNull) {
       val.template emplace<0>();
       return;
@@ -88,7 +92,7 @@ class OptionalOfImpl
       // 1/100 chance of returning an empty.
       val.template emplace<0>();
     } else {
-      inner_.Mutate(std::get<1>(val), prng, only_shrink);
+      inner_.Mutate(std::get<1>(val), prng, metadata, only_shrink);
     }
   }
 
@@ -155,12 +159,13 @@ class OptionalOfImpl
     return 0;
   }
 
-  uint64_t MutateSelectedField(corpus_type& val, absl::BitGenRef prng,
-                               bool only_shrink,
-                               uint64_t selected_field_index) {
+  uint64_t MutateSelectedField(
+      corpus_type& val, absl::BitGenRef prng,
+      const domain_implementor::MutationMetadata& metadata, bool only_shrink,
+      uint64_t selected_field_index) {
     if (val.index() == 1) {
-      return inner_.MutateSelectedField(std::get<1>(val), prng, only_shrink,
-                                        selected_field_index);
+      return inner_.MutateSelectedField(std::get<1>(val), prng, metadata,
+                                        only_shrink, selected_field_index);
     }
     return 0;
   }
diff --git a/fuzztest/internal/domains/overlap_of_impl.h b/fuzztest/internal/domains/overlap_of_impl.h
index 65137b24..2c10cfce 100644
--- a/fuzztest/internal/domains/overlap_of_impl.h
+++ b/fuzztest/internal/domains/overlap_of_impl.h
@@ -45,6 +45,8 @@ class OverlapOfImpl
   using typename OverlapOfImpl::DomainBase::corpus_type;
   using typename OverlapOfImpl::DomainBase::value_type;
 
+  using OverlapOfImpl::DomainBase::Mutate;
+
   static_assert(
       std::conjunction_v<std::is_same<value_type, value_type_t<Inner>>...>,
       "All overlapping domains must have the same value_type.");
@@ -65,7 +67,9 @@ class OverlapOfImpl
     }
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     const size_t index = val.index();
     std::optional<value_type> orig_value;
     std::optional<corpus_type> mutant_corpus;
@@ -85,7 +89,7 @@ class OverlapOfImpl
           FUZZTEST_INTERNAL_CHECK(inner_corpus.has_value(),
                                   "Mutate() called on a user value that is not "
                                   "valid in all overlapping domains");
-          domain.Mutate(*inner_corpus, prng, only_shrink);
+          domain.Mutate(*inner_corpus, prng, metadata, only_shrink);
           mutant_corpus =
               corpus_type(std::in_place_index<I>, *std::move(inner_corpus));
         });
@@ -93,7 +97,8 @@ class OverlapOfImpl
         mutant_corpus = val;
         Switch<kNumDomains>(index, [&](auto I) {
           auto& domain = std::get<I>(domains_);
-          domain.Mutate(std::get<I>(*mutant_corpus), prng, only_shrink);
+          domain.Mutate(std::get<I>(*mutant_corpus), prng, metadata,
+                        only_shrink);
         });
       }
       FUZZTEST_INTERNAL_CHECK(mutant_corpus.has_value(),
diff --git a/fuzztest/internal/domains/protobuf_domain_impl.h b/fuzztest/internal/domains/protobuf_domain_impl.h
index 6b1a024a..3a8682c8 100644
--- a/fuzztest/internal/domains/protobuf_domain_impl.h
+++ b/fuzztest/internal/domains/protobuf_domain_impl.h
@@ -431,6 +431,8 @@ class ProtobufDomainUntypedImpl
   using typename ProtobufDomainUntypedImpl::DomainBase::corpus_type;
   using typename ProtobufDomainUntypedImpl::DomainBase::value_type;
 
+  using ProtobufDomainUntypedImpl::DomainBase::Mutate;
+
   explicit ProtobufDomainUntypedImpl(PrototypePtr<Message> prototype,
                                      bool use_lazy_initialization)
       : prototype_(std::move(prototype)),
@@ -486,13 +488,15 @@ class ProtobufDomainUntypedImpl
     return val;
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     if (GetFieldCount(prototype_.Get()->GetDescriptor()) == 0) return;
     // TODO(JunyangShao): Maybe make CountNumberOfFields static.
     uint64_t total_weight = CountNumberOfFields(val);
     uint64_t selected_weight = absl::Uniform(absl::IntervalClosedClosed, prng,
                                              uint64_t{1}, total_weight);
-    MutateSelectedField(val, prng, only_shrink, selected_weight);
+    MutateSelectedField(val, prng, metadata, only_shrink, selected_weight);
   }
 
   auto GetPrinter() const { return ProtobufPrinter{}; }
@@ -611,9 +615,10 @@ class ProtobufDomainUntypedImpl
     return total_weight;
   }
 
-  uint64_t MutateSelectedField(corpus_type& val, absl::BitGenRef prng,
-                               bool only_shrink,
-                               uint64_t selected_field_index) {
+  uint64_t MutateSelectedField(
+      corpus_type& val, absl::BitGenRef prng,
+      const domain_implementor::MutationMetadata& metadata, bool only_shrink,
+      uint64_t selected_field_index) {
     uint64_t field_counter = 0;
     auto descriptor = prototype_.Get()->GetDescriptor();
     if (GetFieldCount(descriptor) == 0) return field_counter;
@@ -625,7 +630,8 @@ class ProtobufDomainUntypedImpl
       }
       ++field_counter;
       if (field_counter == selected_field_index) {
-        VisitProtobufField(field, MutateVisitor{prng, only_shrink, *this, val});
+        VisitProtobufField(
+            field, MutateVisitor{prng, metadata, only_shrink, *this, val});
         return field_counter;
       }
 
@@ -635,12 +641,12 @@ class ProtobufDomainUntypedImpl
         if (field->is_repeated()) {
           field_counter +=
               GetSubDomain<ProtoMessageTag, true>(field).MutateSelectedField(
-                  val_it->second, prng, only_shrink,
+                  val_it->second, prng, metadata, only_shrink,
                   selected_field_index - field_counter);
         } else {
           field_counter +=
               GetSubDomain<ProtoMessageTag, false>(field).MutateSelectedField(
-                  val_it->second, prng, only_shrink,
+                  val_it->second, prng, metadata, only_shrink,
                   selected_field_index - field_counter);
         }
       }
@@ -947,6 +953,7 @@ class ProtobufDomainUntypedImpl
 
   struct MutateVisitor {
     absl::BitGenRef prng;
+    const domain_implementor::MutationMetadata& metadata;
     bool only_shrink;
     ProtobufDomainUntypedImpl& self;
     corpus_type& val;
@@ -959,7 +966,7 @@ class ProtobufDomainUntypedImpl
 
       if (is_present) {
         // Mutate the element
-        domain.Mutate(it->second, prng, only_shrink);
+        domain.Mutate(it->second, prng, metadata, only_shrink);
         return;
       }
 
@@ -997,7 +1004,7 @@ class ProtobufDomainUntypedImpl
         // Switch the inner domain for maps to use flat_hash_map instead.
         corpus_type corpus_copy;
         auto& copy = corpus_copy[field->number()] = it->second;
-        domain.Mutate(copy, prng, only_shrink);
+        domain.Mutate(copy, prng, metadata, only_shrink);
         auto v = self.GetValue(corpus_copy);
         // We need to roundtrip through serialization to really dedup. The
         // reflection API alone doesn't cut it.
@@ -1008,7 +1015,7 @@ class ProtobufDomainUntypedImpl
           it->second = std::move(copy);
         }
       } else {
-        domain.Mutate(it->second, prng, only_shrink);
+        domain.Mutate(it->second, prng, metadata, only_shrink);
       }
     }
   };
@@ -1244,7 +1251,7 @@ class ProtobufDomainUntypedImpl
           auto val = domain.Init(gen);
           auto descriptor = GetDescriptor<is_repeated>(val);
           for (int i = 0; !descriptor && i < kMaxTry; ++i) {
-            domain.Mutate(val, gen, /*only_shrink=*/false);
+            domain.Mutate(val, gen, {}, false);
             descriptor = GetDescriptor<is_repeated>(val);
           }
           FUZZTEST_INTERNAL_CHECK_PRECONDITION(
@@ -1789,6 +1796,8 @@ class ProtobufDomainImpl
   using typename ProtobufDomainImpl::DomainBase::value_type;
   using FieldDescriptor = ProtobufFieldDescriptor<typename T::Message>;
 
+  using ProtobufDomainImpl::DomainBase::Mutate;
+
   corpus_type Init(absl::BitGenRef prng) {
     if (auto seed = this->MaybeGetRandomSeed(prng)) return *seed;
     return inner_.Init(prng);
@@ -1802,8 +1811,10 @@ class ProtobufDomainImpl
     return inner_.MutateNumberOfProtoFields(val);
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
-    inner_.Mutate(val, prng, only_shrink);
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
+    inner_.Mutate(val, prng, metadata, only_shrink);
   }
 
   value_type GetValue(const corpus_type& v) const {
@@ -2239,13 +2250,16 @@ class ArbitraryImpl<T, std::enable_if_t<is_protocol_buffer_enum_v<T>>>
  public:
   using typename ArbitraryImpl::DomainBase::value_type;
 
+  using ArbitraryImpl::DomainBase::Mutate;
+
   value_type Init(absl::BitGenRef prng) {
     if (auto seed = this->MaybeGetRandomSeed(prng)) return *seed;
     const int index = absl::Uniform(prng, 0, descriptor()->value_count());
     return static_cast<T>(descriptor()->value(index)->number());
   }
 
-  void Mutate(value_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(value_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata&, bool only_shrink) {
     if (only_shrink) {
       std::vector<int> numbers;
       for (int i = 0; i < descriptor()->value_count(); ++i) {
diff --git a/fuzztest/internal/domains/smart_pointer_of_impl.h b/fuzztest/internal/domains/smart_pointer_of_impl.h
index 2b3d53b7..ea57eb7d 100644
--- a/fuzztest/internal/domains/smart_pointer_of_impl.h
+++ b/fuzztest/internal/domains/smart_pointer_of_impl.h
@@ -47,6 +47,8 @@ class SmartPointerOfImpl
   using typename SmartPointerOfImpl::DomainBase::corpus_type;
   using typename SmartPointerOfImpl::DomainBase::value_type;
 
+  using SmartPointerOfImpl::DomainBase::Mutate;
+
   static_assert(
       Requires<T>(
           [](auto x) -> std::enable_if_t<std::is_pointer_v<decltype(x.get())>,
@@ -67,7 +69,9 @@ class SmartPointerOfImpl
     return corpus_type();
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     const bool has_value = val.index() == 1;
     if (!has_value) {
       // Only add a value if we are not shrinking.
@@ -76,7 +80,7 @@ class SmartPointerOfImpl
       // 1/100 chance of returning an empty.
       val.template emplace<0>();
     } else {
-      GetOrMakeInner().Mutate(std::get<1>(val), prng, only_shrink);
+      GetOrMakeInner().Mutate(std::get<1>(val), prng, metadata, only_shrink);
     }
   }
 
diff --git a/fuzztest/internal/domains/unique_elements_container_of_impl.h b/fuzztest/internal/domains/unique_elements_container_of_impl.h
index 68423f1a..2f2aa621 100644
--- a/fuzztest/internal/domains/unique_elements_container_of_impl.h
+++ b/fuzztest/internal/domains/unique_elements_container_of_impl.h
@@ -52,6 +52,8 @@ class UniqueElementsContainerImpl
   using typename UniqueElementsContainerImpl::DomainBase::corpus_type;
   using typename UniqueElementsContainerImpl::DomainBase::value_type;
 
+  using UniqueElementsContainerImpl::DomainBase::Mutate;
+
   UniqueElementsContainerImpl() = default;
   explicit UniqueElementsContainerImpl(InnerDomain inner)
       : unique_domain_(std::move(inner)) {}
@@ -64,8 +66,10 @@ class UniqueElementsContainerImpl
     return unique_domain_.Init(prng);
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
-    unique_domain_.Mutate(val, prng, only_shrink);
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
+    unique_domain_.Mutate(val, prng, metadata, only_shrink);
   }
 
   value_type GetValue(const corpus_type& v) const {
diff --git a/fuzztest/internal/domains/value_mutation_helpers.h b/fuzztest/internal/domains/value_mutation_helpers.h
index fa5f7885..13179abd 100644
--- a/fuzztest/internal/domains/value_mutation_helpers.h
+++ b/fuzztest/internal/domains/value_mutation_helpers.h
@@ -23,7 +23,7 @@
 #include "absl/numeric/int128.h"
 #include "absl/random/bit_gen_ref.h"
 #include "absl/random/random.h"
-#include "./fuzztest/internal/coverage.h"
+#include "./fuzztest/internal/domains/mutation_metadata.h"
 #include "./fuzztest/internal/meta.h"
 #include "./fuzztest/internal/table_of_recent_compares.h"
 
@@ -91,6 +91,7 @@ T SampleFromUniformRange(absl::BitGenRef prng, T min, T max) {
 //  dictionary fails to mutate, fall back to uniform.
 template <unsigned char RANGE, typename T, typename IntegerDictionaryT>
 void RandomWalkOrUniformOrDict(absl::BitGenRef prng, T& val, T min, T max,
+                               domain_implementor::ConstCmpTablesPtr cmp_tables,
                                const IntegerDictionaryT& temporary_dict,
                                const IntegerDictionaryT& permanent_dict,
                                std::optional<T>& permanent_dict_candidate) {
@@ -98,8 +99,7 @@ void RandomWalkOrUniformOrDict(absl::BitGenRef prng, T& val, T min, T max,
       std::numeric_limits<T>::is_integer &&
       (sizeof(T) == 1 || sizeof(T) == 2 || sizeof(T) == 4 || sizeof(T) == 8);
   const bool can_use_memory_dictionary =
-      is_memory_dictionary_compatible_integer &&
-      GetExecutionCoverage() != nullptr;
+      is_memory_dictionary_compatible_integer && cmp_tables != nullptr;
   const int action_count = 2 + can_use_memory_dictionary;
   int action = absl::Uniform(prng, 0, action_count);
   // Random walk.
@@ -143,9 +143,7 @@ void RandomWalkOrUniformOrDict(absl::BitGenRef prng, T& val, T min, T max,
             },
             [&] {
               auto entry = IntegerDictionary<T>::GetRandomTORCEntry(
-                  val, prng,
-                  GetExecutionCoverage()->GetTablesOfRecentCompares(), min,
-                  max);
+                  val, prng, *cmp_tables, min, max);
               if (entry.has_value()) {
                 val = *entry;
               } else {
diff --git a/fuzztest/internal/domains/variant_of_impl.h b/fuzztest/internal/domains/variant_of_impl.h
index 5ee71f14..a7ef2827 100644
--- a/fuzztest/internal/domains/variant_of_impl.h
+++ b/fuzztest/internal/domains/variant_of_impl.h
@@ -43,6 +43,8 @@ class VariantOfImpl : public domain_implementor::DomainBase<
   using typename VariantOfImpl::DomainBase::corpus_type;
   using typename VariantOfImpl::DomainBase::value_type;
 
+  using VariantOfImpl::DomainBase::Mutate;
+
   VariantOfImpl() = default;
   explicit VariantOfImpl(std::in_place_t, Inner... inner)
       : inner_(std::move(inner)...) {}
@@ -56,7 +58,9 @@ class VariantOfImpl : public domain_implementor::DomainBase<
         });
   }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     // Flip a coin to choose between generating a value of an alternative type
     // and mutating the value of the current type. Assign more weight to the
     // mutating case in order to explore more on a given type before we start
@@ -65,7 +69,8 @@ class VariantOfImpl : public domain_implementor::DomainBase<
       val = Init(prng);
     } else {
       Switch<sizeof...(Inner)>(val.index(), [&](auto I) {
-        std::get<I>(inner_).Mutate(std::get<I>(val), prng, only_shrink);
+        std::get<I>(inner_).Mutate(std::get<I>(val), prng, metadata,
+                                   only_shrink);
       });
     }
   }
diff --git a/fuzztest/internal/runtime.cc b/fuzztest/internal/runtime.cc
index 6b3b4914..998635a7 100644
--- a/fuzztest/internal/runtime.cc
+++ b/fuzztest/internal/runtime.cc
@@ -57,6 +57,7 @@
 #include "./fuzztest/internal/configuration.h"
 #include "./fuzztest/internal/corpus_database.h"
 #include "./fuzztest/internal/coverage.h"
+#include "./fuzztest/internal/domains/mutation_metadata.h"
 #include "./fuzztest/internal/fixture_driver.h"
 #include "./fuzztest/internal/flag_name.h"
 #include "./fuzztest/internal/io.h"
@@ -81,6 +82,7 @@ inline constexpr int TRAP_PERF = 6;
 namespace fuzztest::internal {
 namespace {
 
+using ::fuzztest::domain_implementor::MutationMetadata;
 using ::fuzztest::domain_implementor::PrintMode;
 using ::fuzztest::domain_implementor::RawSink;
 
@@ -655,7 +657,7 @@ bool FuzzTestFuzzerImpl::ReplayInputsIfAvailable(
     while (!ShouldStop()) {
       auto copy = *to_minimize;
       for (int i = 0; i < num_mutations; ++i) {
-        params_domain_.Mutate(copy, prng, true);
+        params_domain_.Mutate(copy, prng, {}, true);
       }
       num_mutations = std::max(1, num_mutations - 1);
       // We compare the serialized version. Not very efficient but works for
@@ -710,7 +712,8 @@ std::optional<corpus_type> FuzzTestFuzzerImpl::ReadReproducerToMinimize() {
   return *reproducer;
 }
 
-void FuzzTestFuzzerImpl::MutateValue(Input& input, absl::BitGenRef prng) {
+void FuzzTestFuzzerImpl::MutateValue(Input& input, absl::BitGenRef prng,
+                                     const MutationMetadata& metadata) {
   // Do a random number of mutations on the value at once, skewed
   // towards 1 and decreasing probability as we go up.
   // Doing multiple smaller mutations at once allows reaching states that
@@ -728,7 +731,7 @@ void FuzzTestFuzzerImpl::MutateValue(Input& input, absl::BitGenRef prng) {
   // optimized in any significant way.
   for (int mutations_at_once = absl::Poisson<int>(prng) + 1;
        mutations_at_once > 0; --mutations_at_once) {
-    params_domain_.Mutate(input.args, prng, /* only_shrink= */ false);
+    params_domain_.Mutate(input.args, prng, metadata, /*only_shrink=*/false);
   }
 }
 
@@ -796,7 +799,10 @@ void FuzzTestFuzzerImpl::TrySampleAndUpdateInMemoryCorpus(Input sample,
   auto [new_coverage, run_time] = TrySample(sample, write_to_file);
   if (execution_coverage_ != nullptr &&
       (stats_.runs % 4096 == 0 || new_coverage)) {
-    params_domain_.UpdateMemoryDictionary(sample.args);
+    auto* coverage = GetExecutionCoverage();
+    params_domain_.UpdateMemoryDictionary(
+        sample.args,
+        coverage == nullptr ? nullptr : &coverage->GetTablesOfRecentCompares());
   }
   if (!new_coverage) return;
   // New coverage, update corpus and weights.
@@ -993,7 +999,7 @@ void FuzzTestFuzzerImpl::RunInUnitTestMode(const Configuration& configuration) {
       // generate a new one through Init.
       constexpr size_t num_mutations_per_value = 100;
       if (i % num_mutations_per_value < num_mutations_per_value - 1) {
-        MutateValue(mutation, prng);
+        MutateValue(mutation, prng, {});
       } else {
         mutation.args = params_domain_.Init(prng);
       }
@@ -1075,7 +1081,7 @@ void FuzzTestFuzzerImpl::MinimizeNonFatalFailureLocally(absl::BitGenRef prng) {
     // reach another failure, but prefer a low number of mutations (thus Zipf).
     for (int num_mutations = absl::Zipf(prng, 10); num_mutations >= 0;
          --num_mutations) {
-      params_domain_.Mutate(copy.args, prng, /* only_shrink= */ true);
+      params_domain_.Mutate(copy.args, prng, {}, true);
     }
     // Only run it if it actually is different. Random mutations might
     // not actually change the value, or we have reached a minimum that can't be
@@ -1199,6 +1205,10 @@ int FuzzTestFuzzerImpl::RunInFuzzingMode(int* /*argc*/, char*** /*argv*/,
       try_input_and_process_counterexample({params_domain_.Init(prng)});
     }
 
+    MutationMetadata mutation_metadata;
+    if (auto* coverage = GetExecutionCoverage(); coverage != nullptr) {
+      mutation_metadata.cmp_tables = &coverage->GetTablesOfRecentCompares();
+    }
     // Fuzz corpus elements in round robin fashion.
     while (!ShouldStop()) {
       Input input_to_mutate = [&]() -> Input {
@@ -1218,7 +1228,7 @@ int FuzzTestFuzzerImpl::RunInFuzzingMode(int* /*argc*/, char*** /*argv*/,
       for (int i = 0; i < kMutationsPerInput; ++i) {
         if (ShouldStop()) break;
         Input mutation = input_to_mutate;
-        MutateValue(mutation, prng);
+        MutateValue(mutation, prng, mutation_metadata);
         try_input_and_process_counterexample(std::move(mutation));
       }
     }
diff --git a/fuzztest/internal/runtime.h b/fuzztest/internal/runtime.h
index 7f919450..89fd494a 100644
--- a/fuzztest/internal/runtime.h
+++ b/fuzztest/internal/runtime.h
@@ -312,7 +312,8 @@ class FuzzTestFuzzerImpl : public FuzzTestFuzzer {
 
   absl::StatusOr<corpus_type> TryParse(absl::string_view data);
 
-  void MutateValue(Input& input, absl::BitGenRef prng);
+  void MutateValue(Input& input, absl::BitGenRef prng,
+                   const domain_implementor::MutationMetadata& metadata);
 
   void UpdateCorpusDistribution();
 
diff --git a/fuzztest/llvm_fuzzer_wrapper.cc b/fuzztest/llvm_fuzzer_wrapper.cc
index 7b6c7485..bbdd7f3a 100644
--- a/fuzztest/llvm_fuzzer_wrapper.cc
+++ b/fuzztest/llvm_fuzzer_wrapper.cc
@@ -16,6 +16,9 @@
 #include "./fuzztest/internal/domains/container_of_impl.h"
 #include "./fuzztest/internal/domains/domain_base.h"
 #include "./fuzztest/internal/io.h"
+#ifndef FUZZTEST_USE_CENTIPEDE
+#include "./fuzztest/internal/coverage.h"
+#endif
 
 ABSL_DECLARE_FLAG(std::string, llvm_fuzzer_wrapper_dict_file);
 ABSL_DECLARE_FLAG(std::string, llvm_fuzzer_wrapper_corpus_dir);
@@ -135,7 +138,12 @@ extern "C" size_t LLVMFuzzerMutate(uint8_t* data, size_t size,
   domain.WithMaxSize(max_size);
   absl::BitGen bitgen;
   InplaceVector<uint8_t> val(data, size);
-  domain.Mutate(val, bitgen, false);
+  fuzztest::domain_implementor::MutationMetadata metadata;
+  if (auto* coverage = fuzztest::internal::GetExecutionCoverage();
+      coverage != nullptr) {
+    metadata.cmp_tables = &coverage->GetTablesOfRecentCompares();
+  }
+  domain.Mutate(val, bitgen, metadata, false);
   return val.size();
 }
 
@@ -151,14 +159,16 @@ class ArbitraryByteVector
 
   ArbitraryByteVector() { WithMaxSize(kByteArrayMaxLen); }
 
-  void Mutate(corpus_type& val, absl::BitGenRef prng, bool only_shrink) {
+  void Mutate(corpus_type& val, absl::BitGenRef prng,
+              const fuzztest::domain_implementor::MutationMetadata& metadata,
+              bool only_shrink) {
     if (LLVMFuzzerCustomMutator) {
       const size_t size = val.size();
       const size_t max_size = only_shrink ? size : kByteArrayMaxLen;
       val.resize(max_size);
       val.resize(LLVMFuzzerCustomMutator(val.data(), size, max_size, prng()));
     } else {
-      Base::Mutate(val, prng, only_shrink);
+      Base::Mutate(val, prng, metadata, only_shrink);
     }
   }
 };