security: make Campaign mutation audits atomic

src/govoplan_campaign/backend/persistence/campaigns.py

@@ -157,6 +157,7 @@ def create_campaign_version_from_json(
     raw_json: dict[str, Any],
     source_filename: str | None = None,
     source_base_path: str | None = None,
+    commit: bool = True,
 ) -> tuple[Campaign, CampaignVersion]:
     assert_server_safe_campaign_paths(
         raw_json,
@@ -211,8 +212,11 @@ def create_campaign_version_from_json(
     session.flush()
     campaign.current_version_id = version.id
     session.add(campaign)
-    _write_campaign_snapshot(version)
+    if commit:
-    session.commit()
+        _write_campaign_snapshot(version)
+        session.commit()
+    else:
+        session.flush()
     return campaign, version
 
 

src/govoplan_campaign/backend/persistence/versions.py

@@ -208,6 +208,7 @@ def create_minimal_campaign(
     description: str | None = None,
     current_flow: str = CampaignVersionFlow.CREATE.value,
     current_step: str = "basics",
+    commit: bool = True,
 ) -> tuple[Campaign, CampaignVersion]:
     existing = session.query(Campaign).filter(Campaign.tenant_id == tenant_id, Campaign.external_id == external_id).one_or_none()
     if existing:
@@ -241,8 +242,11 @@ def create_minimal_campaign(
     session.flush()
     campaign.current_version_id = version.id
     session.add(campaign)
-    _write_campaign_snapshot(version)
+    if commit:
-    session.commit()
+        _write_campaign_snapshot(version)
+        session.commit()
+    else:
+        session.flush()
     return campaign, version
 
 
@@ -338,6 +342,7 @@ def fork_campaign_version_for_edit(
     source_base_path: str | None = None,
     autosave: bool = True,
     migrate_legacy_mail_settings: bool = False,
+    commit: bool = True,
 ) -> CampaignVersion:
     """Create the next sole working version from immutable campaign history.
 
@@ -407,8 +412,11 @@ def fork_campaign_version_for_edit(
     campaign.current_version_id = new_version.id
     campaign.status = CampaignStatus.DRAFT.value
     session.add(campaign)
-    _write_campaign_snapshot(new_version)
+    if commit:
-    session.commit()
+        _write_campaign_snapshot(new_version)
+        session.commit()
+    else:
+        session.flush()
     return new_version
 
 
@@ -466,6 +474,7 @@ def unlock_validated_campaign_version(
     tenant_id: str,
     campaign_id: str,
     version_id: str,
+    commit: bool = True,
 ) -> CampaignVersion:
     """Unlock a validation snapshot so it can be edited again.
 
@@ -515,7 +524,10 @@ def unlock_validated_campaign_version(
     campaign.status = CampaignStatus.DRAFT.value
     session.add(version)
     session.add(campaign)
-    session.commit()
+    if commit:
+        session.commit()
+    else:
+        session.flush()
     return version
 
 def update_campaign_version(
@@ -534,6 +546,7 @@ def update_campaign_version(
     source_base_path: str | None = None,
     autosave: bool = False,
     migrate_legacy_mail_settings: bool = False,
+    commit: bool = True,
 ) -> CampaignVersion:
     if raw_json is not None or source_filename is not None or source_base_path is not None:
         assert_server_safe_campaign_paths(
@@ -602,8 +615,11 @@ def update_campaign_version(
     session.add(version)
     session.add(campaign)
     session.flush()
-    _write_campaign_snapshot(version)
+    if commit:
-    session.commit()
+        _write_campaign_snapshot(version)
+        session.commit()
+    else:
+        session.flush()
     return version
 
 
@@ -616,6 +632,7 @@ def update_campaign_review_state(
     inspection_complete: bool,
     reviewed_message_keys: list[str],
     user_id: str | None,
+    commit: bool = True,
 ) -> CampaignVersion:
     """Persist review acknowledgement without mutating the locked campaign data.
 
@@ -646,7 +663,10 @@ def update_campaign_review_state(
         user_id=user_id,
     )
     session.add(version)
-    session.commit()
+    if commit:
+        session.commit()
+    else:
+        session.flush()
     return version
 
 
@@ -728,6 +748,7 @@ def lock_campaign_version_temporarily(
     campaign_id: str,
     version_id: str,
     user_id: str | None,
+    commit: bool = True,
 ) -> CampaignVersion:
     """Apply a reversible user-requested lock without changing workflow state."""
 
@@ -752,7 +773,10 @@ def lock_campaign_version_temporarily(
     version.user_locked_at = datetime.now(UTC)
     version.user_locked_by_user_id = user_id
     session.add(version)
-    session.commit()
+    if commit:
+        session.commit()
+    else:
+        session.flush()
     return version
 
 
@@ -762,6 +786,7 @@ def unlock_user_locked_campaign_version(
     tenant_id: str,
     campaign_id: str,
     version_id: str,
+    commit: bool = True,
 ) -> CampaignVersion:
     """Remove a reversible user lock without invalidating campaign data."""
 
@@ -785,7 +810,10 @@ def unlock_user_locked_campaign_version(
     version.user_locked_at = None
     version.user_locked_by_user_id = None
     session.add(version)
-    session.commit()
+    if commit:
+        session.commit()
+    else:
+        session.flush()
     return version
 
 
@@ -796,6 +824,7 @@ def permanently_lock_campaign_version(
     campaign_id: str,
     version_id: str,
     user_id: str | None,
+    commit: bool = True,
 ) -> CampaignVersion:
     """Apply an irreversible user lock.
 
@@ -823,7 +852,10 @@ def permanently_lock_campaign_version(
     # Retain published_at as a compatibility marker for existing integrations.
     version.published_at = version.published_at or now
     session.add(version)
-    session.commit()
+    if commit:
+        session.commit()
+    else:
+        session.flush()
     return version
 
 
@@ -834,6 +866,7 @@ def publish_campaign_version(
     campaign_id: str,
     version_id: str,
     user_id: str | None = None,
+    commit: bool = True,
 ) -> CampaignVersion:
     """Backwards-compatible alias for the permanent user lock."""
 
@@ -843,6 +876,7 @@ def publish_campaign_version(
         campaign_id=campaign_id,
         version_id=version_id,
         user_id=user_id,
+        commit=commit,
     )
 
 

src/govoplan_campaign/backend/router.py

@@ -390,14 +390,22 @@ def _campaign_version_detail_response(
             details=audit_details,
             commit=True,
         )
-        return CampaignVersionDetailResponse.model_validate(version)
+        _write_current_version_snapshot_if_available(version)
+        return CampaignVersionDetailResponse.model_validate(
+            version,
+            context=_campaign_response_context(principal),
+        )
     except LockedCampaignVersionError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail=str(exc)) from exc
     except CampaignPathSecurityError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_CONTENT, detail=str(exc)) from exc
     except CampaignPersistenceError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
     except Exception as exc:
+        session.rollback()
         if validation_error_status is None:
             raise
         raise HTTPException(status_code=validation_error_status, detail=str(exc)) from exc
@@ -437,6 +445,7 @@ def _update_campaign_version_detail_response(
             source_base_path=payload.source_base_path,
             autosave=autosave,
             migrate_legacy_mail_settings=payload.migrate_legacy_mail_settings,
+            commit=False,
         ),
         audit_action=audit_action,
         details=lambda version: {
@@ -611,6 +620,7 @@ def create_campaign(
             raw_json=payload.config,
             source_filename=payload.source_filename,
             source_base_path=payload.source_base_path,
+            commit=False,
         )
         audit_from_principal(
             session,
@@ -621,11 +631,20 @@ def create_campaign(
             details={"version_id": version.id, "external_id": campaign.external_id},
             commit=True,
         )
+        _write_current_version_snapshot_if_available(version)
     except HTTPException:
+        session.rollback()
         raise
     except Exception as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_CONTENT, detail=str(exc)) from exc
-    return CampaignCreateResponse(campaign=CampaignResponse.model_validate(campaign), version=CampaignVersionResponse.model_validate(version))
+    return CampaignCreateResponse(
+        campaign=CampaignResponse.model_validate(campaign),
+        version=CampaignVersionResponse.model_validate(
+            version,
+            context=_campaign_response_context(principal),
+        ),
+    )
 
 
 @router.post("/new", response_model=CampaignCreateResponse)
@@ -651,6 +670,7 @@ def create_minimal_campaign_endpoint(
             description=payload.description,
             current_flow=payload.current_flow,
             current_step=payload.current_step,
+            commit=False,
         )
         audit_from_principal(
             session,
@@ -661,9 +681,20 @@ def create_minimal_campaign_endpoint(
             details={"version_id": version.id, "external_id": campaign.external_id},
             commit=True,
         )
-        return CampaignCreateResponse(campaign=CampaignResponse.model_validate(campaign), version=CampaignVersionResponse.model_validate(version))
+        _write_current_version_snapshot_if_available(version)
+        return CampaignCreateResponse(
+            campaign=CampaignResponse.model_validate(campaign),
+            version=CampaignVersionResponse.model_validate(
+                version,
+                context=_campaign_response_context(principal),
+            ),
+        )
     except CampaignPersistenceError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_CONTENT, detail=str(exc)) from exc
+    except Exception:
+        session.rollback()
+        raise
 
 
 
@@ -1045,14 +1076,30 @@ def _campaign_workspace_response(
                 campaign_id=campaign_id,
                 version_id=selected_version_id,
                 include_jobs=False,
+                include_diagnostics=has_scope(principal, "campaigns:diagnostic:read"),
             )
         except CampaignReportError:
             summary_payload = None
 
     return CampaignWorkspaceResponse(
         campaign=CampaignResponse.model_validate(campaign),
-        versions=[CampaignVersionResponse.model_validate(item) for item in versions] if include_versions else [],
+        versions=[
-        current_version=CampaignVersionDetailResponse.model_validate(current_version) if current_version is not None else None,
+            CampaignVersionResponse.model_validate(
+                item,
+                context=_campaign_response_context(principal),
+            )
+            for item in versions
+        ]
+        if include_versions
+        else [],
+        current_version=(
+            CampaignVersionDetailResponse.model_validate(
+                current_version,
+                context=_campaign_response_context(principal),
+            )
+            if current_version is not None
+            else None
+        ),
         summary=summary_payload,
         selected_version_id=selected_version_id,
     )
@@ -1167,7 +1214,13 @@ def _campaign_workspace_delta_response(
     )
     return CampaignWorkspaceDeltaResponse(
         campaign=CampaignResponse.model_validate(campaign) if delta.changed_campaign else None,
-        versions=_campaign_workspace_delta_versions(session, campaign, delta, include_versions=include_versions),
+        versions=_campaign_workspace_delta_versions(
+            session,
+            principal,
+            campaign,
+            delta,
+            include_versions=include_versions,
+        ),
         current_version=_campaign_workspace_delta_current_version(
             session,
             principal,
@@ -1240,6 +1293,7 @@ def _campaign_workspace_delta_deleted(entries: list[object]) -> list[dict[str, o
 
 def _campaign_workspace_delta_versions(
     session: Session,
+    principal: ApiPrincipal,
     campaign: Campaign,
     delta: _WorkspaceDeltaState,
     *,
@@ -1253,7 +1307,13 @@ def _campaign_workspace_delta_versions(
         .order_by(CampaignVersion.version_number.desc())
         .all()
     )
-    return [CampaignVersionResponse.model_validate(item) for item in versions]
+    return [
+        CampaignVersionResponse.model_validate(
+            item,
+            context=_campaign_response_context(principal),
+        )
+        for item in versions
+    ]
 
 
 def _campaign_workspace_delta_current_version(
@@ -1274,7 +1334,14 @@ def _campaign_workspace_delta_current_version(
         .filter(CampaignVersion.id == delta.selected_version_id, CampaignVersion.campaign_id == campaign.id)
         .one_or_none()
     )
-    return CampaignVersionDetailResponse.model_validate(current_version) if current_version is not None else None
+    return (
+        CampaignVersionDetailResponse.model_validate(
+            current_version,
+            context=_campaign_response_context(principal),
+        )
+        if current_version is not None
+        else None
+    )
 
 
 def _campaign_workspace_delta_summary(
@@ -1296,6 +1363,7 @@ def _campaign_workspace_delta_summary(
             campaign_id=campaign_id,
             version_id=delta.selected_version_id,
             include_jobs=False,
+            include_diagnostics=has_scope(principal, "campaigns:diagnostic:read"),
         )
     except CampaignReportError:
         return None
@@ -1378,17 +1446,25 @@ def update_campaign_metadata_endpoint(
 
     _sync_campaign_metadata_to_current_version(session, campaign)
     session.add(campaign)
-    session.commit()
+    session.flush()
+    try:
+        audit_from_principal(
+            session,
+            principal,
+            action="campaign.metadata_updated",
+            object_type="campaign",
+            object_id=campaign.id,
+            details={"external_id": campaign.external_id, "name": campaign.name},
+            commit=True,
+        )
+    except Exception:
+        session.rollback()
+        raise
     session.refresh(campaign)
-    audit_from_principal(
+    if campaign.current_version_id:
-        session,
+        current_version = session.get(CampaignVersion, campaign.current_version_id)
-        principal,
+        if current_version is not None:
-        action="campaign.metadata_updated",
+            _write_current_version_snapshot_if_available(current_version)
-        object_type="campaign",
-        object_id=campaign.id,
-        details={"external_id": campaign.external_id, "name": campaign.name},
-        commit=True,
-    )
     return CampaignResponse.model_validate(campaign)
 
 
@@ -1458,7 +1534,13 @@ def list_versions(
         .order_by(CampaignVersion.version_number.desc())
         .all()
     )
-    return [CampaignVersionResponse.model_validate(item) for item in versions]
+    return [
+        CampaignVersionResponse.model_validate(
+            item,
+            context=_campaign_response_context(principal),
+        )
+        for item in versions
+    ]
 
 
 @router.get("/{campaign_id}/versions/{version_id}", response_model=CampaignVersionDetailResponse)
@@ -1474,7 +1556,10 @@ def get_version_detail(
         version = get_campaign_version_for_tenant(
             session, tenant_id=principal.tenant_id, campaign_id=campaign_id, version_id=version_id
         )
-        return CampaignVersionDetailResponse.model_validate(version)
+        return CampaignVersionDetailResponse.model_validate(
+            version,
+            context=_campaign_response_context(principal),
+        )
     except CampaignPersistenceError as exc:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
 
@@ -1523,6 +1608,7 @@ def fork_version_for_edit(
             source_base_path=payload.source_base_path,
             autosave=True,
             migrate_legacy_mail_settings=payload.migrate_legacy_mail_settings,
+            commit=False,
         )
         campaign = _get_campaign_for_tenant(session, campaign_id, principal.tenant_id)
         audit_from_principal(
@@ -1539,16 +1625,26 @@ def fork_version_for_edit(
             },
             commit=True,
         )
+        _write_current_version_snapshot_if_available(version)
         return CampaignCreateResponse(
             campaign=CampaignResponse.model_validate(campaign),
-            version=CampaignVersionResponse.model_validate(version),
+            version=CampaignVersionResponse.model_validate(
+                version,
+                context=_campaign_response_context(principal),
+            ),
         )
     except LockedCampaignVersionError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail=str(exc)) from exc
     except CampaignPathSecurityError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_CONTENT, detail=str(exc)) from exc
     except CampaignPersistenceError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
+    except Exception:
+        session.rollback()
+        raise
 
 
 @router.post("/{campaign_id}/versions/{version_id}/unlock-validation", response_model=CampaignVersionDetailResponse)
@@ -1574,6 +1670,7 @@ def unlock_version_validation(
             tenant_id=principal.tenant_id,
             campaign_id=campaign_id,
             version_id=version_id,
+            commit=False,
         ),
         audit_action="campaign.version_validation_unlocked",
     )
@@ -1597,6 +1694,7 @@ def lock_version_temporarily(
             campaign_id=campaign_id,
             version_id=version_id,
             user_id=principal.user.id,
+            commit=False,
         ),
         audit_action="campaign.version_user_locked_temporarily",
     )
@@ -1619,6 +1717,7 @@ def unlock_version_user_lock(
             tenant_id=principal.tenant_id,
             campaign_id=campaign_id,
             version_id=version_id,
+            commit=False,
         ),
         audit_action="campaign.version_user_lock_removed",
     )
@@ -1642,6 +1741,7 @@ def lock_version_permanently(
             campaign_id=campaign_id,
             version_id=version_id,
             user_id=principal.user.id,
+            commit=False,
         ),
         audit_action="campaign.version_user_locked_permanently",
     )
@@ -1694,8 +1794,11 @@ def set_version_step(
     principal: ApiPrincipal = Depends(require_scope("campaigns:campaign:update")),
 ):
     _get_campaign_for_principal(session, campaign_id, principal, write=True)
-    try:
+    return _campaign_version_detail_response(
-        version = update_campaign_version(
+        session,
+        principal,
+        campaign_id,
+        lambda: update_campaign_version(
             session,
             tenant_id=principal.tenant_id,
             campaign_id=campaign_id,
@@ -1703,12 +1806,15 @@ def set_version_step(
             current_flow=payload.current_flow,
             current_step=payload.current_step,
             autosave=True,
-        )
+            commit=False,
-        return CampaignVersionDetailResponse.model_validate(version)
+        ),
-    except LockedCampaignVersionError as exc:
+        audit_action="campaign.version_step_updated",
-        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail=str(exc)) from exc
+        details={
-    except CampaignPersistenceError as exc:
+            "campaign_id": campaign_id,
-        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
+            "current_flow": payload.current_flow,
+            "current_step": payload.current_step,
+        },
+    )
 
 
 @router.post("/{campaign_id}/versions/{version_id}/review-state", response_model=CampaignVersionDetailResponse)
@@ -1729,6 +1835,7 @@ def set_version_review_state(
             inspection_complete=payload.inspection_complete,
             reviewed_message_keys=payload.reviewed_message_keys,
             user_id=principal.user.id,
+            commit=False,
         )
         audit_from_principal(
             session,
@@ -1743,11 +1850,19 @@ def set_version_review_state(
             },
             commit=True,
         )
-        return CampaignVersionDetailResponse.model_validate(version)
+        return CampaignVersionDetailResponse.model_validate(
+            version,
+            context=_campaign_response_context(principal),
+        )
     except LockedCampaignVersionError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail=str(exc)) from exc
     except CampaignPersistenceError as exc:
+        session.rollback()
         raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_CONTENT, detail=str(exc)) from exc
+    except Exception:
+        session.rollback()
+        raise
 
 
 @router.post("/{campaign_id}/versions/{version_id}/validate-partial", response_model=CampaignPartialValidationResponse)
@@ -1797,6 +1912,7 @@ def publish_version(
             campaign_id=campaign_id,
             version_id=version_id,
             user_id=principal.user.id,
+            commit=False,
         ),
         audit_action="campaign.version_user_locked_permanently",
     )
@@ -1867,7 +1983,10 @@ def validate_version(
             },
             commit=True,
         )
-        return public_campaign_payload(result)
+        return public_campaign_payload(
+            result,
+            include_diagnostics=has_scope(principal, "campaigns:diagnostic:read"),
+        )
     except HTTPException:
         raise
     except CampaignPersistenceError as exc:
@@ -1902,7 +2021,10 @@ def build_version(
             details={"write_eml": payload.write_eml if payload else True, "built_count": result.get("built_count")},
             commit=True,
         )
-        return public_campaign_payload(result)
+        return public_campaign_payload(
+            result,
+            include_diagnostics=has_scope(principal, "campaigns:diagnostic:read"),
+        )
     except CampaignPersistenceError as exc:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
     except Exception as exc:
@@ -1941,8 +2063,6 @@ def _job_summary_payload(
             imap_status=job.imap_status,
         ),
         "queued_at": job.queued_at,
-        "claimed_at": job.claimed_at,
-        "smtp_started_at": job.smtp_started_at,
         "outcome_unknown_at": job.outcome_unknown_at,
         "sent_at": job.sent_at,
         "created_at": job.created_at,
@@ -2646,6 +2766,7 @@ def campaign_summary(
             version_id=version_id,
             include_jobs=include_jobs,
             include_recent_failures=include_jobs,
+            include_diagnostics=has_scope(principal, "campaigns:diagnostic:read"),
         )
     except CampaignReportError as exc:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
@@ -2672,6 +2793,7 @@ def campaign_report(
             version_id=version_id,
             include_jobs=include_jobs,
             include_recent_failures=include_jobs,
+            include_diagnostics=has_scope(principal, "campaigns:diagnostic:read"),
         )
     except CampaignReportError as exc:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
@@ -2690,7 +2812,11 @@ def campaign_jobs_csv(
 
     try:
         csv_text = generate_jobs_csv(
-            session, tenant_id=principal.tenant_id, campaign_id=campaign_id, version_id=version_id
+            session,
+            tenant_id=principal.tenant_id,
+            campaign_id=campaign_id,
+            version_id=version_id,
+            include_diagnostics=has_scope(principal, "campaigns:diagnostic:read"),
         )
     except CampaignReportError as exc:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc

tests/test_campaign_audit_atomicity.py

@@ -0,0 +1,119 @@
+from __future__ import annotations
+
+from types import SimpleNamespace
+from unittest.mock import MagicMock, patch
+
+import pytest
+from fastapi import HTTPException
+
+from govoplan_campaign.backend import router
+from govoplan_campaign.backend.schemas import CampaignUpdateRequest, CampaignVersionUpdateRequest
+
+
+def _principal() -> SimpleNamespace:
+    return SimpleNamespace(
+        tenant_id="tenant-1",
+        user=SimpleNamespace(id="user-1"),
+        api_key=None,
+    )
+
+
+def test_version_update_rolls_back_when_its_audit_record_cannot_be_written() -> None:
+    session = MagicMock()
+    principal = _principal()
+    version = SimpleNamespace(
+        id="version-1",
+        raw_json={},
+        current_flow="manual",
+        current_step="recipients",
+    )
+
+    def mutate(*_args, **kwargs):
+        assert kwargs["commit"] is False
+        session.flush()
+        return version
+
+    with (
+        patch.object(router, "_get_campaign_for_principal"),
+        patch.object(router, "_get_version_for_tenant", return_value=version),
+        patch.object(router, "update_campaign_version", side_effect=mutate),
+        patch.object(router, "audit_from_principal", side_effect=RuntimeError("audit unavailable")),
+    ):
+        with pytest.raises(HTTPException, match="audit unavailable") as captured:
+            router._update_campaign_version_detail_response(  # noqa: SLF001 - transaction regression test
+                session,
+                principal,  # type: ignore[arg-type]
+                "campaign-1",
+                "version-1",
+                CampaignVersionUpdateRequest(current_step="recipients"),
+                autosave=True,
+                audit_action="campaign.version_autosaved",
+            )
+
+    assert captured.value.status_code == 422
+    session.commit.assert_not_called()
+    session.rollback.assert_called_once_with()
+
+
+def test_version_fork_rolls_back_when_its_audit_record_cannot_be_written() -> None:
+    session = MagicMock()
+    principal = _principal()
+    campaign = SimpleNamespace(id="campaign-1")
+    source = SimpleNamespace(id="version-1", campaign_id="campaign-1", raw_json={})
+    forked = SimpleNamespace(id="version-2", campaign_id="campaign-1", version_number=2)
+
+    def mutate(*_args, **kwargs):
+        assert kwargs["commit"] is False
+        session.flush()
+        return forked
+
+    with (
+        patch.object(router, "_get_campaign_for_principal", return_value=campaign),
+        patch.object(router, "_require_permission"),
+        patch.object(router, "_get_version_for_tenant", return_value=source),
+        patch.object(router, "_get_campaign_for_tenant", return_value=campaign),
+        patch.object(router, "fork_campaign_version_for_edit", side_effect=mutate),
+        patch.object(router, "audit_from_principal", side_effect=RuntimeError("audit unavailable")),
+    ):
+        with pytest.raises(RuntimeError, match="audit unavailable"):
+            router.fork_version_for_edit(
+                "campaign-1",
+                "version-1",
+                CampaignVersionUpdateRequest(),
+                session=session,
+                principal=principal,  # type: ignore[arg-type]
+            )
+
+    session.commit.assert_not_called()
+    session.rollback.assert_called_once_with()
+
+
+def test_metadata_update_rolls_back_when_its_audit_record_cannot_be_written() -> None:
+    session = MagicMock()
+    principal = _principal()
+    campaign = SimpleNamespace(
+        id="campaign-1",
+        tenant_id="tenant-1",
+        external_id="C-1",
+        name="Old name",
+        description=None,
+        status="draft",
+        current_version_id=None,
+    )
+
+    with (
+        patch.object(router, "_get_campaign_for_principal", return_value=campaign),
+        patch.object(router, "_sync_campaign_metadata_to_current_version"),
+        patch.object(router, "audit_from_principal", side_effect=RuntimeError("audit unavailable")),
+    ):
+        with pytest.raises(RuntimeError, match="audit unavailable"):
+            router.update_campaign_metadata_endpoint(
+                "campaign-1",
+                CampaignUpdateRequest(name="New name"),
+                session=session,
+                principal=principal,  # type: ignore[arg-type]
+            )
+
+    session.flush.assert_called_once_with()
+    session.commit.assert_not_called()
+    session.rollback.assert_called_once_with()