diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,3 +6,4 @@
 tenacity
 cassandra-driver >= 3.19.0, != 3.21.0
 deprecated
+typing-extensions
diff --git a/swh/storage/algos/snapshot.py b/swh/storage/algos/snapshot.py
--- a/swh/storage/algos/snapshot.py
+++ b/swh/storage/algos/snapshot.py
@@ -27,18 +27,18 @@
             * **branches**: a dict of branches contained in the snapshot
               whose keys are the branches' names.
     """
-    ret = storage.snapshot_get(snapshot_id)
+    ret = storage.snapshot_get_branches(snapshot_id)
 
     if not ret:
         return
 
-    next_branch = ret.pop("next_branch", None)
+    next_branch = ret["next_branch"]
     while next_branch:
         data = storage.snapshot_get_branches(snapshot_id, branches_from=next_branch)
         ret["branches"].update(data["branches"])
-        next_branch = data.get("next_branch")
+        next_branch = data["next_branch"]
 
-    return ret
+    return Snapshot(id=ret["id"], branches=ret["branches"])
 
 
 def snapshot_get_latest(
@@ -95,9 +95,9 @@
         if snapshot is None:
             return None
         snapshot.pop("next_branch")
+        return Snapshot(**snapshot)
     else:
-        snapshot = snapshot_get_all_branches(storage, snapshot_id)
-    return Snapshot.from_dict(snapshot) if snapshot else None
+        return snapshot_get_all_branches(storage, snapshot_id)
 
 
 def snapshot_id_get_from_revision(
@@ -127,11 +127,11 @@
             snapshot = snapshot_get_all_branches(storage, snapshot_id)
             if not snapshot:
                 continue
-            for branch_name, branch in snapshot["branches"].items():
+            for branch_name, branch in snapshot.branches.items():
                 if (
                     branch is not None
-                    and branch["target_type"] == TargetType.REVISION.value
-                    and branch["target"] == revision_id
+                    and branch.target_type == TargetType.REVISION
+                    and branch.target == revision_id
                 ):  # snapshot found
                     return snapshot_id
 
diff --git a/swh/storage/cassandra/cql.py b/swh/storage/cassandra/cql.py
--- a/swh/storage/cassandra/cql.py
+++ b/swh/storage/cassandra/cql.py
@@ -586,7 +586,7 @@
     )
     def snapshot_branch_get(
         self, snapshot_id: Sha1Git, from_: bytes, limit: int, *, statement
-    ) -> None:
+    ) -> ResultSet:
         return self._execute_with_retries(statement, [snapshot_id, from_, limit])
 
     ##########################
diff --git a/swh/storage/cassandra/storage.py b/swh/storage/cassandra/storage.py
--- a/swh/storage/cassandra/storage.py
+++ b/swh/storage/cassandra/storage.py
@@ -26,6 +26,8 @@
     OriginVisit,
     OriginVisitStatus,
     Snapshot,
+    SnapshotBranch,
+    TargetType,
     Origin,
     MetadataAuthority,
     MetadataAuthorityType,
@@ -34,7 +36,13 @@
     RawExtrinsicMetadata,
     Sha1Git,
 )
-from swh.storage.interface import ListOrder, PagedResult, Sha1, VISIT_STATUSES
+from swh.storage.interface import (
+    ListOrder,
+    PagedResult,
+    PartialBranches,
+    Sha1,
+    VISIT_STATUSES,
+)
 from swh.storage.objstorage import ObjStorage
 from swh.storage.writer import JournalWriter
 from swh.storage.utils import map_optional, now
@@ -612,7 +620,17 @@
         return self._cql_runner.snapshot_missing(snapshots)
 
     def snapshot_get(self, snapshot_id: Sha1Git) -> Optional[Dict[str, Any]]:
-        return self.snapshot_get_branches(snapshot_id)
+        d = self.snapshot_get_branches(snapshot_id)
+        if d is None:
+            return None
+        return {
+            "id": d["id"],
+            "branches": {
+                name: branch.to_dict() if branch else None
+                for (name, branch) in d["branches"].items()
+            },
+            "next_branch": d["next_branch"],
+        }
 
     def snapshot_get_by_origin_visit(
         self, origin: str, visit: int
@@ -643,7 +661,7 @@
         branches_from: bytes = b"",
         branches_count: int = 1000,
         target_types: Optional[List[str]] = None,
-    ) -> Optional[Dict[str, Any]]:
+    ) -> Optional[PartialBranches]:
         if self._cql_runner.snapshot_missing([snapshot_id]):
             # Makes sure we don't fetch branches for a snapshot that is
             # being added.
@@ -682,18 +700,18 @@
         else:
             last_branch = None
 
-        branches_d = {
-            branch.name: {"target": branch.target, "target_type": branch.target_type,}
-            if branch.target
-            else None
-            for branch in branches
-        }
-
-        return {
-            "id": snapshot_id,
-            "branches": branches_d,
-            "next_branch": last_branch,
-        }
+        return PartialBranches(
+            id=snapshot_id,
+            branches={
+                branch.name: None
+                if branch.target is None
+                else SnapshotBranch(
+                    target=branch.target, target_type=TargetType(branch.target_type)
+                )
+                for branch in branches
+            },
+            next_branch=last_branch,
+        )
 
     def snapshot_get_random(self) -> Sha1Git:
         return self._cql_runner.snapshot_get_random().id
diff --git a/swh/storage/in_memory.py b/swh/storage/in_memory.py
--- a/swh/storage/in_memory.py
+++ b/swh/storage/in_memory.py
@@ -55,7 +55,12 @@
     Sha1Git,
 )
 from swh.model.hashutil import DEFAULT_ALGORITHMS, hash_to_bytes, hash_to_hex
-from swh.storage.interface import ListOrder, PagedResult, VISIT_STATUSES
+from swh.storage.interface import (
+    ListOrder,
+    PagedResult,
+    PartialBranches,
+    VISIT_STATUSES,
+)
 from swh.storage.objstorage import ObjStorage
 from swh.storage.utils import now
 
@@ -593,7 +598,17 @@
                 yield id
 
     def snapshot_get(self, snapshot_id: Sha1Git) -> Optional[Dict[str, Any]]:
-        return self.snapshot_get_branches(snapshot_id)
+        d = self.snapshot_get_branches(snapshot_id)
+        if d is None:
+            return None
+        return {
+            "id": d["id"],
+            "branches": {
+                name: branch.to_dict() if branch else None
+                for (name, branch) in d["branches"].items()
+            },
+            "next_branch": d["next_branch"],
+        }
 
     def snapshot_get_by_origin_visit(
         self, origin: str, visit: int
@@ -627,7 +642,7 @@
         branches_from: bytes = b"",
         branches_count: int = 1000,
         target_types: Optional[List[str]] = None,
-    ) -> Optional[Dict[str, Any]]:
+    ) -> Optional[PartialBranches]:
         snapshot = self._snapshots.get(snapshot_id)
         if snapshot is None:
             return None
@@ -659,16 +674,9 @@
             else:
                 next_branch = sorted_branch_names[to_index]
 
-        branches = {
-            name: branch.to_dict() if branch else None
-            for (name, branch) in branches.items()
-        }
-
-        return {
-            "id": snapshot_id,
-            "branches": branches,
-            "next_branch": next_branch,
-        }
+        return PartialBranches(
+            id=snapshot_id, branches=branches, next_branch=next_branch,
+        )
 
     def snapshot_get_random(self) -> Sha1Git:
         return random.choice(list(self._snapshots))
diff --git a/swh/storage/interface.py b/swh/storage/interface.py
--- a/swh/storage/interface.py
+++ b/swh/storage/interface.py
@@ -8,6 +8,7 @@
 from enum import Enum
 from typing import Any, Dict, Iterable, List, Optional, Tuple, TypeVar, Union
 
+from typing_extensions import TypedDict
 
 from swh.core.api import remote_api_endpoint
 from swh.core.api.classes import PagedResult as CorePagedResult
@@ -22,6 +23,7 @@
     Release,
     Snapshot,
     SkippedContent,
+    SnapshotBranch,
     MetadataAuthority,
     MetadataAuthorityType,
     MetadataFetcher,
@@ -39,6 +41,19 @@
     DESC = "desc"
 
 
+class PartialBranches(TypedDict):
+    """Type of the dictionary returned by snapshot_get_branches"""
+
+    id: Sha1Git
+    """Identifier of the snapshot"""
+    branches: Dict[bytes, Optional[SnapshotBranch]]
+    """A dict of branches contained in the snapshot
+    whose keys are the branches' names"""
+    next_branch: Optional[bytes]
+    """The name of the first branch not returned or :const:`None` if
+    the snapshot has less than the request number of branches."""
+
+
 TResult = TypeVar("TResult")
 PagedResult = CorePagedResult[TResult, str]
 
@@ -720,7 +735,7 @@
         branches_from: bytes = b"",
         branches_count: int = 1000,
         target_types: Optional[List[str]] = None,
-    ) -> Optional[Dict[str, Any]]:
+    ) -> Optional[PartialBranches]:
         """Get the content, possibly partial, of a snapshot with the given id
 
         The branches of the snapshot are iterated in the lexicographical
diff --git a/swh/storage/storage.py b/swh/storage/storage.py
--- a/swh/storage/storage.py
+++ b/swh/storage/storage.py
@@ -40,6 +40,8 @@
     Sha1,
     Sha1Git,
     Snapshot,
+    SnapshotBranch,
+    TargetType,
     SHA1_SIZE,
     MetadataAuthority,
     MetadataAuthorityType,
@@ -48,7 +50,12 @@
     RawExtrinsicMetadata,
 )
 from swh.model.hashutil import DEFAULT_ALGORITHMS, hash_to_bytes, hash_to_hex
-from swh.storage.interface import ListOrder, PagedResult, VISIT_STATUSES
+from swh.storage.interface import (
+    ListOrder,
+    PagedResult,
+    PartialBranches,
+    VISIT_STATUSES,
+)
 from swh.storage.objstorage import ObjStorage
 from swh.storage.utils import now
 
@@ -736,7 +743,15 @@
     def snapshot_get(
         self, snapshot_id: Sha1Git, db=None, cur=None
     ) -> Optional[Dict[str, Any]]:
-        return self.snapshot_get_branches(snapshot_id, db=db, cur=cur)
+        d = self.snapshot_get_branches(snapshot_id)
+        return {
+            "id": d["id"],
+            "branches": {
+                name: branch.to_dict() if branch else None
+                for (name, branch) in d["branches"].items()
+            },
+            "next_branch": d["next_branch"],
+        }
 
     @timed
     @db_transaction(statement_timeout=2000)
@@ -767,13 +782,9 @@
         target_types: Optional[List[str]] = None,
         db=None,
         cur=None,
-    ) -> Optional[Dict[str, Any]]:
+    ) -> Optional[PartialBranches]:
         if snapshot_id == EMPTY_SNAPSHOT_ID:
-            return {
-                "id": snapshot_id,
-                "branches": {},
-                "next_branch": None,
-            }
+            return PartialBranches(id=snapshot_id, branches={}, next_branch=None,)
 
         branches = {}
         next_branch = None
@@ -787,24 +798,27 @@
                 cur=cur,
             )
         )
-        for branch in fetched_branches[:branches_count]:
-            branch = dict(zip(db.snapshot_get_cols, branch))
-            del branch["snapshot_id"]
-            name = branch.pop("name")
-            if branch == {"target": None, "target_type": None}:
+        for row in fetched_branches[:branches_count]:
+            branch_d = dict(zip(db.snapshot_get_cols, row))
+            del branch_d["snapshot_id"]
+            name = branch_d.pop("name")
+            if branch_d["target"] is None and branch_d["target_type"] is None:
                 branch = None
+            else:
+                assert branch_d["target_type"] is not None
+                branch = SnapshotBranch(
+                    target=branch_d["target"],
+                    target_type=TargetType(branch_d["target_type"]),
+                )
             branches[name] = branch
 
         if len(fetched_branches) > branches_count:
-            branch = dict(zip(db.snapshot_get_cols, fetched_branches[-1]))
-            next_branch = branch["name"]
+            next_branch = dict(zip(db.snapshot_get_cols, fetched_branches[-1]))["name"]
 
         if branches:
-            return {
-                "id": snapshot_id,
-                "branches": branches,
-                "next_branch": next_branch,
-            }
+            return PartialBranches(
+                id=snapshot_id, branches=branches, next_branch=next_branch,
+            )
 
         return None
 
diff --git a/swh/storage/tests/algos/test_snapshot.py b/swh/storage/tests/algos/test_snapshot.py
--- a/swh/storage/tests/algos/test_snapshot.py
+++ b/swh/storage/tests/algos/test_snapshot.py
@@ -31,7 +31,7 @@
     swh_storage.snapshot_add([snapshot])
 
     returned_snapshot = snapshot_get_all_branches(swh_storage, snapshot.id)
-    assert snapshot.to_dict() == returned_snapshot
+    assert snapshot == returned_snapshot
 
 
 @given(branch_name=branch_names(), branch_target=branch_targets(only_objects=True))
@@ -45,7 +45,7 @@
     swh_storage.snapshot_add([snapshot])
 
     returned_snapshot = snapshot_get_all_branches(swh_storage, snapshot.id)
-    assert snapshot.to_dict() == returned_snapshot
+    assert snapshot == returned_snapshot
 
 
 def test_snapshot_get_latest_none(swh_storage, sample_data):
diff --git a/swh/storage/tests/test_storage.py b/swh/storage/tests/test_storage.py
--- a/swh/storage/tests/test_storage.py
+++ b/swh/storage/tests/test_storage.py
@@ -37,6 +37,7 @@
     Release,
     Revision,
     Snapshot,
+    TargetType,
 )
 from swh.model.hypothesis_strategies import objects
 from swh.storage import get_storage
@@ -2618,7 +2619,7 @@
         swh_storage.snapshot_add([complete_snapshot])
 
         snp_id = complete_snapshot.id
-        branches = complete_snapshot.to_dict()["branches"]
+        branches = complete_snapshot.branches
         branch_names = list(sorted(branches))
 
         # Test branch_from
@@ -2686,7 +2687,7 @@
         )
 
         snp_id = complete_snapshot.id
-        branches = complete_snapshot.to_dict()["branches"]
+        branches = complete_snapshot.branches
 
         snapshot = swh_storage.snapshot_get_branches(
             snp_id, target_types=["release", "revision"]
@@ -2697,7 +2698,7 @@
             "branches": {
                 name: tgt
                 for name, tgt in branches.items()
-                if tgt and tgt["target_type"] in ["release", "revision"]
+                if tgt and tgt.target_type in [TargetType.RELEASE, TargetType.REVISION]
             },
             "next_branch": None,
         }
@@ -2711,7 +2712,7 @@
             "branches": {
                 name: tgt
                 for name, tgt in branches.items()
-                if tgt and tgt["target_type"] == "alias"
+                if tgt and tgt.target_type == TargetType.ALIAS
             },
             "next_branch": None,
         }
@@ -2724,7 +2725,7 @@
         swh_storage.snapshot_add([complete_snapshot])
 
         snp_id = complete_snapshot.id
-        branches = complete_snapshot.to_dict()["branches"]
+        branches = complete_snapshot.branches
         branch_names = list(sorted(branches))
 
         # Test branch_from