diff --git a/tests/core/pyspec/eth2spec/debug/decode.py b/tests/core/pyspec/eth2spec/debug/decode.py
index 30bfd487bd..a1a3cd9c24 100644
--- a/tests/core/pyspec/eth2spec/debug/decode.py
+++ b/tests/core/pyspec/eth2spec/debug/decode.py
@@ -2,7 +2,8 @@
 from eth2spec.utils.ssz.ssz_impl import hash_tree_root
 from eth2spec.utils.ssz.ssz_typing import (
     uint, Container, List, boolean,
-    Vector, ByteVector, ByteList, Union, View
+    Vector, ByteVector, ByteList, Union, View,
+    Profile, StableContainer,
 )
 
 
@@ -27,6 +28,43 @@ def decode(data: Any, typ):
             assert (data["hash_tree_root"][2:] ==
                     hash_tree_root(ret).hex())
         return ret
+    elif issubclass(typ, StableContainer):
+        temp = {}
+        for field_name, field_type in typ.fields().items():
+            if data[field_name] is None:
+                temp[field_name] = None
+                if field_name + "_hash_tree_root" in data:
+                    assert (data[field_name + "_hash_tree_root"][2:] ==
+                            '00' * 32)
+            else:
+                temp[field_name] = decode(data[field_name], field_type)
+                if field_name + "_hash_tree_root" in data:
+                    assert (data[field_name + "_hash_tree_root"][2:] ==
+                            hash_tree_root(temp[field_name]).hex())
+        ret = typ(**temp)
+        if "hash_tree_root" in data:
+            assert (data["hash_tree_root"][2:] ==
+                    hash_tree_root(ret).hex())
+        return ret
+    elif issubclass(typ, Profile):
+        temp = {}
+        for field_name, [field_type, is_optional] in typ.fields().items():
+            if data[field_name] is None:
+                assert is_optional
+                temp[field_name] = None
+                if field_name + "_hash_tree_root" in data:
+                    assert (data[field_name + "_hash_tree_root"][2:] ==
+                            '00' * 32)
+            else:
+                temp[field_name] = decode(data[field_name], field_type)
+                if field_name + "_hash_tree_root" in data:
+                    assert (data[field_name + "_hash_tree_root"][2:] ==
+                            hash_tree_root(temp[field_name]).hex())
+        ret = typ(**temp)
+        if "hash_tree_root" in data:
+            assert (data["hash_tree_root"][2:] ==
+                    hash_tree_root(ret).hex())
+        return ret
     elif issubclass(typ, Union):
         selector = int(data["selector"])
         options = typ.options()
diff --git a/tests/core/pyspec/eth2spec/debug/encode.py b/tests/core/pyspec/eth2spec/debug/encode.py
index d93f7cf5ef..6f80092056 100644
--- a/tests/core/pyspec/eth2spec/debug/encode.py
+++ b/tests/core/pyspec/eth2spec/debug/encode.py
@@ -1,7 +1,8 @@
 from eth2spec.utils.ssz.ssz_impl import hash_tree_root, serialize
 from eth2spec.utils.ssz.ssz_typing import (
     uint, boolean,
-    Bitlist, Bitvector, Container, Vector, List, Union
+    Bitlist, Bitvector, Container, Vector, List, Union,
+    Profile, StableContainer,
 )
 
 
@@ -31,6 +32,21 @@ def encode(value, include_hash_tree_roots=False):
         if include_hash_tree_roots:
             ret["hash_tree_root"] = '0x' + hash_tree_root(value).hex()
         return ret
+    elif isinstance(value, (StableContainer, Profile)):
+        ret = {}
+        for field_name in value.fields().keys():
+            field_value = getattr(value, field_name)
+            if field_value is None:
+                ret[field_name] = None
+                if include_hash_tree_roots:
+                    ret[field_name + "_hash_tree_root"] = '0x' + '00' * 32
+            else:
+                ret[field_name] = encode(field_value, include_hash_tree_roots)
+                if include_hash_tree_roots:
+                    ret[field_name + "_hash_tree_root"] = '0x' + hash_tree_root(field_value).hex()
+        if include_hash_tree_roots:
+            ret["hash_tree_root"] = '0x' + hash_tree_root(value).hex()
+        return ret
     elif isinstance(value, Union):
         inner_value = value.value()
         return {
diff --git a/tests/core/pyspec/eth2spec/debug/random_value.py b/tests/core/pyspec/eth2spec/debug/random_value.py
index ff80ee0f4e..f507bf3c33 100644
--- a/tests/core/pyspec/eth2spec/debug/random_value.py
+++ b/tests/core/pyspec/eth2spec/debug/random_value.py
@@ -5,7 +5,8 @@
 
 from eth2spec.utils.ssz.ssz_typing import (
     View, BasicView, uint, Container, List, boolean,
-    Vector, ByteVector, ByteList, Bitlist, Bitvector, Union
+    Vector, ByteVector, ByteList, Bitlist, Bitvector, Union,
+    Profile, StableContainer,
 )
 
 # in bytes
@@ -115,6 +116,29 @@ def get_random_ssz_object(rng: Random,
                 get_random_ssz_object(rng, field_type, max_bytes_length, max_list_length, mode, chaos)
             for field_name, field_type in fields.items()
         })
+    elif issubclass(typ, StableContainer):
+        fields = typ.fields()
+        # StableContainer
+        return typ(**{
+            field_name:
+                rng.choice([
+                    None,
+                    get_random_ssz_object(rng, field_type, max_bytes_length, max_list_length, mode, chaos)
+                ])
+            for field_name, field_type in fields.items()
+        })
+    elif issubclass(typ, Profile):
+        fields = typ.fields()
+        # Profile
+        return typ(**{
+            field_name:
+                rng.choice([
+                    None if is_optional else get_random_ssz_object(
+                        rng, field_type, max_bytes_length, max_list_length, mode, chaos),
+                    get_random_ssz_object(rng, field_type, max_bytes_length, max_list_length, mode, chaos)
+                ])
+            for field_name, [field_type, is_optional] in fields.items()
+        })
     elif issubclass(typ, Union):
         options = typ.options()
         selector: int
diff --git a/tests/core/pyspec/eth2spec/utils/ssz/ssz_typing.py b/tests/core/pyspec/eth2spec/utils/ssz/ssz_typing.py
index 1f3db2fe00..054c20e034 100644
--- a/tests/core/pyspec/eth2spec/utils/ssz/ssz_typing.py
+++ b/tests/core/pyspec/eth2spec/utils/ssz/ssz_typing.py
@@ -7,6 +7,7 @@
 from remerkleable.bitfields import Bitvector, Bitlist
 from remerkleable.byte_arrays import ByteVector, Bytes1, Bytes4, Bytes8, Bytes32, Bytes48, Bytes96, ByteList
 from remerkleable.core import BasicView, View, Path
+from remerkleable.stable_container import Profile, StableContainer
 
 
 Bytes20 = ByteVector[20]  # type: ignore
diff --git a/tests/generators/ssz_generic/main.py b/tests/generators/ssz_generic/main.py
index 2e96ce2e87..eeb79a4c0f 100644
--- a/tests/generators/ssz_generic/main.py
+++ b/tests/generators/ssz_generic/main.py
@@ -6,6 +6,8 @@
 import ssz_boolean
 import ssz_uints
 import ssz_container
+import ssz_stablecontainer
+import ssz_profile
 from eth2spec.test.helpers.constants import PHASE0
 
 
@@ -43,4 +45,6 @@ def cases_fn() -> Iterable[gen_typing.TestCase]:
         create_provider("uints", "invalid", ssz_uints.invalid_cases),
         create_provider("containers", "valid", ssz_container.valid_cases),
         create_provider("containers", "invalid", ssz_container.invalid_cases),
+        create_provider("stablecontainers", "valid", ssz_stablecontainer.valid_cases),
+        create_provider("profiles", "valid", ssz_profile.valid_cases),
     ])
diff --git a/tests/generators/ssz_generic/ssz_profile.py b/tests/generators/ssz_generic/ssz_profile.py
new file mode 100644
index 0000000000..30651ae514
--- /dev/null
+++ b/tests/generators/ssz_generic/ssz_profile.py
@@ -0,0 +1,228 @@
+from ssz_test_case import invalid_test_case, valid_test_case
+from eth2spec.utils.ssz.ssz_typing import View, byte, uint8, uint16, \
+    uint32, uint64, List, ByteList, Vector, Bitvector, Bitlist, Profile
+from eth2spec.utils.ssz.ssz_impl import serialize
+from random import Random
+from typing import Dict, Tuple, Sequence, Callable, Type
+from eth2spec.debug.random_value import RandomizationMode, get_random_ssz_object
+from ssz_stablecontainer import SingleFieldTestStableStruct, SmallTestStableStruct, FixedTestStableStruct, \
+    VarTestStableStruct, ComplexTestStableStruct, BitsStableStruct
+
+
+class SingleFieldTestProfile(Profile[SingleFieldTestStableStruct]):
+    A: byte
+
+
+class SmallTestProfile1(Profile[SmallTestStableStruct]):
+    A: uint16
+    B: uint16
+
+
+class SmallTestProfile2(Profile[SmallTestStableStruct]):
+    A: uint16
+
+
+class SmallTestProfile3(Profile[SmallTestStableStruct]):
+    B: uint16
+
+
+class FixedTestProfile1(Profile[FixedTestStableStruct]):
+    A: uint8
+    B: uint64
+    C: uint32
+
+
+class FixedTestProfile2(Profile[FixedTestStableStruct]):
+    A: uint8
+    B: uint64
+
+
+class FixedTestProfile3(Profile[FixedTestStableStruct]):
+    A: uint8
+    C: uint32
+
+
+class FixedTestProfile4(Profile[FixedTestStableStruct]):
+    C: uint32
+
+
+class VarTestProfile1(Profile[VarTestStableStruct]):
+    A: uint16
+    B: List[uint16, 1024]
+    C: uint8
+
+
+class VarTestProfile2(Profile[VarTestStableStruct]):
+    B: List[uint16, 1024]
+    C: uint8
+
+
+class VarTestProfile3(Profile[VarTestStableStruct]):
+    B: List[uint16, 1024]
+
+
+class ComplexTestProfile1(Profile[ComplexTestStableStruct]):
+    A: uint16
+    B: List[uint16, 128]
+    C: uint8
+    D: ByteList[256]
+    E: VarTestStableStruct
+    F: Vector[FixedTestStableStruct, 4]
+    G: Vector[VarTestStableStruct, 2]
+
+
+class ComplexTestProfile2(Profile[ComplexTestStableStruct]):
+    A: uint16
+    B: List[uint16, 128]
+    C: uint8
+    D: ByteList[256]
+    E: VarTestStableStruct
+
+
+class ComplexTestProfile3(Profile[ComplexTestStableStruct]):
+    A: uint16
+    C: uint8
+    E: VarTestStableStruct
+    G: Vector[VarTestStableStruct, 2]
+
+
+class ComplexTestProfile4(Profile[ComplexTestStableStruct]):
+    B: List[uint16, 128]
+    D: ByteList[256]
+    F: Vector[FixedTestStableStruct, 4]
+
+
+class ComplexTestProfile5(Profile[ComplexTestStableStruct]):
+    E: VarTestStableStruct
+    F: Vector[FixedTestStableStruct, 4]
+    G: Vector[VarTestStableStruct, 2]
+
+
+class BitsProfile1(Profile[BitsStableStruct]):
+    A: Bitlist[5]
+    B: Bitvector[2]
+    C: Bitvector[1]
+    D: Bitlist[6]
+    E: Bitvector[8]
+
+
+class BitsProfile2(Profile[BitsStableStruct]):
+    A: Bitlist[5]
+    B: Bitvector[2]
+    C: Bitvector[1]
+    D: Bitlist[6]
+
+
+class BitsProfile3(Profile[BitsStableStruct]):
+    A: Bitlist[5]
+    D: Bitlist[6]
+    E: Bitvector[8]
+
+
+def container_case_fn(rng: Random, mode: RandomizationMode, typ: Type[View], chaos: bool=False):
+    return get_random_ssz_object(rng, typ,
+                                 max_bytes_length=2000,
+                                 max_list_length=2000,
+                                 mode=mode, chaos=chaos)
+
+
+PRESET_CONTAINERS: Dict[str, Tuple[Type[View], Sequence[int]]] = {
+    'SingleFieldTestProfile': (SingleFieldTestProfile, []),
+    'SmallTestProfile1': (SmallTestProfile1, []),
+    'SmallTestProfile2': (SmallTestProfile2, []),
+    'SmallTestProfile3': (SmallTestProfile3, []),
+    'FixedTestProfile1': (FixedTestProfile1, []),
+    'FixedTestProfile2': (FixedTestProfile2, []),
+    'FixedTestProfile3': (FixedTestProfile3, []),
+    'FixedTestProfile4': (FixedTestProfile4, []),
+    'VarTestProfile1': (VarTestProfile1, [2]),
+    'VarTestProfile2': (VarTestProfile2, [2]),
+    'VarTestProfile3': (VarTestProfile3, [2]),
+    'ComplexTestProfile1': (ComplexTestProfile1, [2, 2 + 4 + 1, 2 + 4 + 1 + 4]),
+    'ComplexTestProfile2': (ComplexTestProfile2, [2, 2 + 4 + 1, 2 + 4 + 1 + 4]),
+    'ComplexTestProfile3': (ComplexTestProfile3, [2, 2 + 4 + 1, 2 + 4 + 1 + 4]),
+    'ComplexTestProfile4': (ComplexTestProfile4, [2, 2 + 4 + 1, 2 + 4 + 1 + 4]),
+    'ComplexTestProfile5': (ComplexTestProfile5, [2, 2 + 4 + 1, 2 + 4 + 1 + 4]),
+    'BitsProfile1': (BitsProfile1, [0, 4 + 1 + 1, 4 + 1 + 1 + 4]),
+    'BitsProfile2': (BitsProfile2, [0, 4 + 1 + 1, 4 + 1 + 1 + 4]),
+    'BitsProfile3': (BitsProfile3, [0, 4 + 1 + 1, 4 + 1 + 1 + 4]),
+}
+
+
+def valid_cases():
+    rng = Random(1234)
+    for (name, (typ, offsets)) in PRESET_CONTAINERS.items():
+        for mode in [RandomizationMode.mode_zero, RandomizationMode.mode_max]:
+            yield f'{name}_{mode.to_name()}', valid_test_case(lambda: container_case_fn(rng, mode, typ))
+
+        if len(offsets) == 0:
+            modes = [RandomizationMode.mode_random, RandomizationMode.mode_zero, RandomizationMode.mode_max]
+        else:
+            modes = list(RandomizationMode)
+
+        for mode in modes:
+            for variation in range(3):
+                yield f'{name}_{mode.to_name()}_chaos_{variation}', \
+                      valid_test_case(lambda: container_case_fn(rng, mode, typ, chaos=True))
+        # Notes: Below is the second wave of iteration, and only the random mode is selected
+        # for container without offset since ``RandomizationMode.mode_zero`` and ``RandomizationMode.mode_max``
+        # are deterministic.
+        modes = [RandomizationMode.mode_random] if len(offsets) == 0 else list(RandomizationMode)
+        for mode in modes:
+            for variation in range(10):
+                yield f'{name}_{mode.to_name()}_{variation}', \
+                      valid_test_case(lambda: container_case_fn(rng, mode, typ))
+
+
+def mod_offset(b: bytes, offset_index: int, change: Callable[[int], int]):
+    return b[:offset_index] + \
+           (change(int.from_bytes(b[offset_index:offset_index + 4], byteorder='little')) & 0xffffffff) \
+           .to_bytes(length=4, byteorder='little') + \
+           b[offset_index + 4:]
+
+
+def invalid_cases():
+    rng = Random(1234)
+    for (name, (typ, offsets)) in PRESET_CONTAINERS.items():
+        # using mode_max_count, so that the extra byte cannot be picked up as normal list content
+        yield f'{name}_extra_byte', \
+              invalid_test_case(lambda: serialize(
+                  container_case_fn(rng, RandomizationMode.mode_max_count, typ)) + b'\xff')
+
+        if len(offsets) != 0:
+            # Note: there are many more ways to have invalid offsets,
+            # these are just example to get clients started looking into hardening ssz.
+            for mode in [RandomizationMode.mode_random,
+                         RandomizationMode.mode_nil_count,
+                         RandomizationMode.mode_one_count,
+                         RandomizationMode.mode_max_count]:
+                for index, offset_index in enumerate(offsets):
+                    yield f'{name}_{mode.to_name()}_offset_{offset_index}_plus_one', \
+                          invalid_test_case(lambda: mod_offset(
+                              b=serialize(container_case_fn(rng, mode, typ)),
+                              offset_index=offset_index,
+                              change=lambda x: x + 1
+                          ))
+                    yield f'{name}_{mode.to_name()}_offset_{offset_index}_zeroed', \
+                          invalid_test_case(lambda: mod_offset(
+                              b=serialize(container_case_fn(rng, mode, typ)),
+                              offset_index=offset_index,
+                              change=lambda x: 0
+                          ))
+                    if index == 0:
+                        yield f'{name}_{mode.to_name()}_offset_{offset_index}_minus_one', \
+                            invalid_test_case(lambda: mod_offset(
+                              b=serialize(container_case_fn(rng, mode, typ)),
+                              offset_index=offset_index,
+                              change=lambda x: x - 1
+                            ))
+                    if mode == RandomizationMode.mode_max_count:
+                        serialized = serialize(container_case_fn(rng, mode, typ))
+                        serialized = serialized + serialized[:2]
+                        yield f'{name}_{mode.to_name()}_last_offset_{offset_index}_overflow', \
+                            invalid_test_case(lambda: serialized)
+                    if mode == RandomizationMode.mode_one_count:
+                        serialized = serialize(container_case_fn(rng, mode, typ))
+                        serialized = serialized + serialized[:1]
+                        yield f'{name}_{mode.to_name()}_last_offset_{offset_index}_wrong_byte_length', \
+                            invalid_test_case(lambda: serialized)
diff --git a/tests/generators/ssz_generic/ssz_stablecontainer.py b/tests/generators/ssz_generic/ssz_stablecontainer.py
new file mode 100644
index 0000000000..b4d782fee6
--- /dev/null
+++ b/tests/generators/ssz_generic/ssz_stablecontainer.py
@@ -0,0 +1,142 @@
+from ssz_test_case import invalid_test_case, valid_test_case
+from eth2spec.utils.ssz.ssz_typing import View, byte, uint8, uint16, \
+    uint32, uint64, List, ByteList, Vector, Bitvector, Bitlist, StableContainer
+from eth2spec.utils.ssz.ssz_impl import serialize
+from random import Random
+from typing import Dict, Tuple, Sequence, Callable, Type, Optional
+from eth2spec.debug.random_value import RandomizationMode, get_random_ssz_object
+
+
+class SingleFieldTestStableStruct(StableContainer[4]):
+    A: Optional[byte]
+
+
+class SmallTestStableStruct(StableContainer[4]):
+    A: Optional[uint16]
+    B: Optional[uint16]
+
+
+class FixedTestStableStruct(StableContainer[4]):
+    A: Optional[uint8]
+    B: Optional[uint64]
+    C: Optional[uint32]
+
+
+class VarTestStableStruct(StableContainer[4]):
+    A: Optional[uint16]
+    B: Optional[List[uint16, 1024]]
+    C: Optional[uint8]
+
+
+class ComplexTestStableStruct(StableContainer[8]):
+    A: Optional[uint16]
+    B: Optional[List[uint16, 128]]
+    C: Optional[uint8]
+    D: Optional[ByteList[256]]
+    E: Optional[VarTestStableStruct]
+    F: Optional[Vector[FixedTestStableStruct, 4]]
+    G: Optional[Vector[VarTestStableStruct, 2]]
+
+
+class BitsStableStruct(StableContainer[8]):
+    A: Optional[Bitlist[5]]
+    B: Optional[Bitvector[2]]
+    C: Optional[Bitvector[1]]
+    D: Optional[Bitlist[6]]
+    E: Optional[Bitvector[8]]
+
+
+def container_case_fn(rng: Random, mode: RandomizationMode, typ: Type[View], chaos: bool=False):
+    return get_random_ssz_object(rng, typ,
+                                 max_bytes_length=2000,
+                                 max_list_length=2000,
+                                 mode=mode, chaos=chaos)
+
+
+PRESET_CONTAINERS: Dict[str, Tuple[Type[View], Sequence[int]]] = {
+    'SingleFieldTestStableStruct': (SingleFieldTestStableStruct, []),
+    'SmallTestStableStruct': (SmallTestStableStruct, []),
+    'FixedTestStableStruct': (FixedTestStableStruct, []),
+    'VarTestStableStruct': (VarTestStableStruct, [2]),
+    'ComplexTestStableStruct': (ComplexTestStableStruct, [2, 2 + 4 + 1, 2 + 4 + 1 + 4]),
+    'BitsStableStruct': (BitsStableStruct, [0, 4 + 1 + 1, 4 + 1 + 1 + 4]),
+}
+
+
+def valid_cases():
+    rng = Random(1234)
+    for (name, (typ, offsets)) in PRESET_CONTAINERS.items():
+        for mode in [RandomizationMode.mode_zero, RandomizationMode.mode_max]:
+            yield f'{name}_{mode.to_name()}', valid_test_case(lambda: container_case_fn(rng, mode, typ))
+
+        if len(offsets) == 0:
+            modes = [RandomizationMode.mode_random, RandomizationMode.mode_zero, RandomizationMode.mode_max]
+        else:
+            modes = list(RandomizationMode)
+
+        for mode in modes:
+            for variation in range(3):
+                yield f'{name}_{mode.to_name()}_chaos_{variation}', \
+                      valid_test_case(lambda: container_case_fn(rng, mode, typ, chaos=True))
+        # Notes: Below is the second wave of iteration, and only the random mode is selected
+        # for container without offset since ``RandomizationMode.mode_zero`` and ``RandomizationMode.mode_max``
+        # are deterministic.
+        modes = [RandomizationMode.mode_random] if len(offsets) == 0 else list(RandomizationMode)
+        for mode in modes:
+            for variation in range(10):
+                yield f'{name}_{mode.to_name()}_{variation}', \
+                      valid_test_case(lambda: container_case_fn(rng, mode, typ))
+
+
+def mod_offset(b: bytes, offset_index: int, change: Callable[[int], int]):
+    return b[:offset_index] + \
+           (change(int.from_bytes(b[offset_index:offset_index + 4], byteorder='little')) & 0xffffffff) \
+           .to_bytes(length=4, byteorder='little') + \
+           b[offset_index + 4:]
+
+
+def invalid_cases():
+    rng = Random(1234)
+    for (name, (typ, offsets)) in PRESET_CONTAINERS.items():
+        # using mode_max_count, so that the extra byte cannot be picked up as normal list content
+        yield f'{name}_extra_byte', \
+              invalid_test_case(lambda: serialize(
+                  container_case_fn(rng, RandomizationMode.mode_max_count, typ)) + b'\xff')
+
+        if len(offsets) != 0:
+            # Note: there are many more ways to have invalid offsets,
+            # these are just example to get clients started looking into hardening ssz.
+            for mode in [RandomizationMode.mode_random,
+                         RandomizationMode.mode_nil_count,
+                         RandomizationMode.mode_one_count,
+                         RandomizationMode.mode_max_count]:
+                for index, offset_index in enumerate(offsets):
+                    yield f'{name}_{mode.to_name()}_offset_{offset_index}_plus_one', \
+                          invalid_test_case(lambda: mod_offset(
+                              b=serialize(container_case_fn(rng, mode, typ)),
+                              offset_index=offset_index,
+                              change=lambda x: x + 1
+                          ))
+                    yield f'{name}_{mode.to_name()}_offset_{offset_index}_zeroed', \
+                          invalid_test_case(lambda: mod_offset(
+                              b=serialize(container_case_fn(rng, mode, typ)),
+                              offset_index=offset_index,
+                              change=lambda x: 0
+                          ))
+                    if index == 0:
+                        yield f'{name}_{mode.to_name()}_offset_{offset_index}_minus_one', \
+                            invalid_test_case(lambda: mod_offset(
+                              b=serialize(container_case_fn(rng, mode, typ)),
+                              offset_index=offset_index,
+                              change=lambda x: x - 1
+                            ))
+                    if mode == RandomizationMode.mode_max_count:
+                        serialized = serialize(container_case_fn(rng, mode, typ))
+                        serialized = serialized + serialized[:2]
+                        yield f'{name}_{mode.to_name()}_last_offset_{offset_index}_overflow', \
+                            invalid_test_case(lambda: serialized)
+                    if mode == RandomizationMode.mode_one_count:
+                        serialized = serialize(container_case_fn(rng, mode, typ))
+                        serialized = serialized + serialized[:1]
+                        yield f'{name}_{mode.to_name()}_last_offset_{offset_index}_wrong_byte_length', \
+                            invalid_test_case(lambda: serialized)