Integrate formal decisions with cases

src/govoplan_cases/backend/decision_path.py

@@ -0,0 +1,478 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, replace
+from datetime import datetime
+import uuid
+
+from sqlalchemy.orm import Session
+
+from govoplan_core.core.access import CAPABILITY_ACCESS_SEMANTIC_DIRECTORY
+from govoplan_core.core.institutional import (
+    CAPABILITY_DECISION_REGISTRY,
+    CAPABILITY_MANDATE_RESOLVER,
+    ActorRepresentationReference,
+    DecisionRegistry,
+    FormalDecision,
+    GovernedContextEnvelope,
+    InstitutionalReference,
+    MandateDefinition,
+    MandateResolution,
+    MandateResolutionRequest,
+    MandateResolver,
+    TemporalRevision,
+    resolve_mandate_candidates,
+)
+from govoplan_cases.backend.domain import CaseRecord
+from govoplan_cases.backend.service import (
+    can_access_case,
+    get_case,
+    update_case,
+)
+
+
+DECISION_READ_SCOPE = "decisions:decision:read"
+DECISION_SENSITIVE_READ_SCOPE = "decisions:decision:read_sensitive"
+DECISION_WRITE_SCOPE = "decisions:decision:write"
+_DECISION_NAMESPACE = uuid.uuid5(
+    uuid.NAMESPACE_URL,
+    "https://govoplan.add-ideas.de/contracts/cases/formal-decision/v1",
+)
+
+
+class CaseDecisionError(ValueError):
+    pass
+
+
+class CaseDecisionUnavailable(CaseDecisionError):
+    pass
+
+
+@dataclass(frozen=True, slots=True)
+class CaseDecisionCommand:
+    expected_case_revision: int
+    effective_at: datetime
+    decision_type: str
+    operative_result: str
+    reasoning: str
+    change_reason: str
+    idempotency_key: str
+    conditions: tuple[str, ...] = ()
+
+
+@dataclass(frozen=True, slots=True)
+class CaseDecisionResult:
+    case: CaseRecord
+    decision: FormalDecision
+    replayed: bool = False
+
+    def to_dict(self) -> dict[str, object]:
+        return {
+            "case": self.case.to_dict(),
+            "decision": self.decision.to_dict(include_protected=True),
+            "replayed": self.replayed,
+        }
+
+
+class CaseDecisionPath:
+    """Record a formal outcome and its exact Case reference atomically."""
+
+    def __init__(self, registry: object | None = None) -> None:
+        self._registry = registry
+
+    def record(
+        self,
+        session: Session,
+        principal: object,
+        *,
+        case_id: str,
+        command: CaseDecisionCommand,
+    ) -> CaseDecisionResult:
+        _validate_command(command)
+        source_case = get_case(
+            session,
+            principal,
+            case_id=case_id,
+            revision=command.expected_case_revision,
+        )
+        current = get_case(session, principal, case_id=case_id)
+        if source_case is None or current is None:
+            raise LookupError("Case not found.")
+        if not can_access_case(
+            session,
+            principal,
+            case_id=case_id,
+            permission="update",
+        ):
+            raise PermissionError("Case update access is denied.")
+
+        decision_id = _decision_id(source_case, command.idempotency_key)
+        existing_ref = next(
+            (
+                item
+                for item in current.decision_refs
+                if item.owner_module == "decisions" and item.object_id == decision_id
+            ),
+            None,
+        )
+        if existing_ref is None and current.revision != command.expected_case_revision:
+            raise CaseDecisionError(
+                "Case revision conflict: reload the Case before recording a Decision."
+            )
+
+        decision_registry = _decision_registry(self._registry)
+        mandate = _resolve_mandate(
+            self._registry,
+            session,
+            principal,
+            case=source_case,
+            command=command,
+        )
+        actor = _resolve_actor(
+            self._registry,
+            principal,
+            case=source_case,
+            mandate=mandate,
+            effective_at=command.effective_at,
+        )
+        decision = _decision(
+            source_case,
+            command=command,
+            decision_id=decision_id,
+            mandate=mandate,
+            actor=actor,
+        )
+        persisted = decision_registry.record_decision(
+            session,
+            principal,
+            decision=decision,
+        )
+
+        if existing_ref is not None:
+            return CaseDecisionResult(
+                case=current,
+                decision=persisted,
+                replayed=True,
+            )
+
+        linked = update_case(
+            session,
+            principal,
+            case_id=case_id,
+            expected_revision=current.revision,
+            changes={"decision_refs": (*current.decision_refs, persisted.reference)},
+            recorded_at=command.effective_at,
+            change_reason=command.change_reason,
+            idempotency_key=f"formal-decision:{command.idempotency_key}",
+        )
+        return CaseDecisionResult(case=linked, decision=persisted)
+
+    def linked(
+        self,
+        session: Session,
+        principal: object,
+        *,
+        case_id: str,
+    ) -> tuple[FormalDecision, ...]:
+        case = get_case(session, principal, case_id=case_id)
+        if case is None:
+            raise LookupError("Case not found.")
+        registry = _decision_registry(self._registry)
+        resolved: list[FormalDecision] = []
+        for reference in case.decision_refs:
+            if reference.owner_module != "decisions":
+                continue
+            item = registry.get_decision(
+                session,
+                principal,
+                reference=reference,
+            )
+            if item is not None:
+                resolved.append(item)
+        return tuple(resolved)
+
+
+def _decision(
+    case: CaseRecord,
+    *,
+    command: CaseDecisionCommand,
+    decision_id: str,
+    mandate: MandateDefinition,
+    actor: ActorRepresentationReference,
+) -> FormalDecision:
+    evidence = tuple(
+        dict.fromkeys((*case.evidence_refs, *case.context.evidence, *mandate.evidence))
+    )
+    legal_bases = tuple(
+        dict.fromkeys((*case.context.legal_bases, *mandate.legal_bases))
+    )
+    if not evidence:
+        raise CaseDecisionError(
+            "A formal Decision requires evidence linked to the exact Case revision."
+        )
+    if not legal_bases:
+        raise CaseDecisionError(
+            "A formal Decision requires an effective legal-basis version."
+        )
+    decision_ref = InstitutionalReference(
+        kind="decision",
+        owner_module="decisions",
+        object_id=decision_id,
+        tenant_id=case.reference.tenant_id,
+        version="1",
+        valid_at=command.effective_at,
+    )
+    temporal = TemporalRevision(
+        revision="1",
+        valid_from=command.effective_at,
+        recorded_at=command.effective_at,
+        change_reason=command.change_reason,
+    )
+    authority_context: GovernedContextEnvelope = replace(
+        case.context,
+        temporal=temporal,
+        actor=actor,
+        mandate_ref=mandate.reference,
+        case_ref=case.reference,
+        party_refs=case.party_refs or case.context.party_refs,
+        decision_ref=decision_ref,
+        record_refs=case.record_refs,
+        legal_bases=legal_bases,
+        evidence=evidence,
+    )
+    return FormalDecision(
+        reference=decision_ref,
+        temporal=temporal,
+        decision_type=command.decision_type.strip(),
+        subject_refs=case.party_refs or (case.reference,),
+        state="decided",
+        authority_context=authority_context,
+        fact_evidence=evidence,
+        legal_bases=legal_bases,
+        operative_result=command.operative_result.strip(),
+        reasoning=command.reasoning.strip(),
+        conditions=tuple(item.strip() for item in command.conditions if item.strip()),
+    )
+
+
+def _resolve_mandate(
+    registry: object | None,
+    session: Session,
+    principal: object,
+    *,
+    case: CaseRecord,
+    command: CaseDecisionCommand,
+) -> MandateDefinition:
+    resolver = _capability(registry, CAPABILITY_MANDATE_RESOLVER)
+    if not isinstance(resolver, MandateResolver):
+        raise CaseDecisionUnavailable(
+            "Formal Decisions require an enabled Mandates resolver."
+        )
+    request = MandateResolutionRequest(
+        tenant_id=case.reference.tenant_id,
+        effective_at=command.effective_at,
+        task_type="cases.formal_decision",
+        authority_type=command.decision_type.strip(),
+        organization_unit_ref=case.context.organization_unit_ref,
+        function_ref=case.context.function_ref,
+        jurisdiction_refs=case.context.jurisdiction_refs,
+    )
+    resolution: MandateResolution = resolver.resolve_mandate(
+        session,
+        principal,
+        request=request,
+    )
+    if not resolution.competent:
+        raise CaseDecisionError(
+            resolution.explanation or "The acting function is not competent to decide."
+        )
+    if resolution.conflict_refs:
+        raise CaseDecisionError(
+            "Mandate resolution has unresolved conflicts: "
+            + ", ".join(resolution.conflict_refs)
+        )
+    verified = resolve_mandate_candidates(request, resolution.mandates)
+    if not verified.competent or len(verified.mandates) != 1:
+        raise CaseDecisionError(
+            verified.explanation
+            or "A formal Decision requires exactly one effective active Mandate."
+        )
+    return verified.mandates[0]
+
+
+def _resolve_actor(
+    registry: object | None,
+    principal: object,
+    *,
+    case: CaseRecord,
+    mandate: MandateDefinition,
+    effective_at: datetime,
+) -> ActorRepresentationReference:
+    directory = _capability(registry, CAPABILITY_ACCESS_SEMANTIC_DIRECTORY)
+    lookup = getattr(directory, "get_function_assignment", None)
+    if not callable(lookup):
+        raise CaseDecisionUnavailable(
+            "Formal Decisions require the Access semantic directory to verify the acting assignment."
+        )
+    acting_id = _text(getattr(principal, "acting_assignment_id", None))
+    granted_ids = tuple(
+        sorted(
+            {
+                str(item).strip()
+                for item in (getattr(principal, "function_assignment_ids", ()) or ())
+                if str(item).strip()
+            }
+        )
+    )
+    if acting_id and acting_id not in granted_ids:
+        raise PermissionError("The selected acting assignment is not active for this account.")
+    candidate_ids = (acting_id,) if acting_id else granted_ids
+    matching = []
+    for assignment_id in candidate_ids:
+        assignment = lookup(assignment_id)
+        if assignment is None or not _assignment_matches(
+            assignment,
+            principal,
+            case=case,
+            effective_at=effective_at,
+        ):
+            continue
+        matching.append(assignment)
+    if not matching:
+        raise PermissionError(
+            "No active acting assignment matches the Case organization and function."
+        )
+    if len(matching) > 1:
+        raise CaseDecisionError(
+            "Select one acting assignment in the title bar before recording the Decision."
+        )
+    assignment = matching[0]
+    return ActorRepresentationReference(
+        tenant_id=case.reference.tenant_id,
+        account_id=_required_principal_text(principal, "account_id"),
+        identity_id=_text(getattr(principal, "identity_id", None))
+        or _text(getattr(assignment, "identity_id", None)),
+        represented_account_id=_text(
+            getattr(principal, "acting_for_account_id", None)
+        ),
+        represented_function_ref=case.context.function_ref,
+        function_assignment_ref=InstitutionalReference(
+            kind="function_assignment",
+            owner_module="access",
+            object_id=str(getattr(assignment, "id")),
+            tenant_id=case.reference.tenant_id,
+            valid_at=effective_at,
+        ),
+        delegation_ref=_text(
+            getattr(assignment, "delegated_from_assignment_id", None)
+        ),
+        mandate_ref=mandate.reference,
+    )
+
+
+def _assignment_matches(
+    assignment: object,
+    principal: object,
+    *,
+    case: CaseRecord,
+    effective_at: datetime,
+) -> bool:
+    organization = case.context.organization_unit_ref
+    function = case.context.function_ref
+    if organization is None or function is None:
+        raise CaseDecisionError(
+            "The Case lacks the responsible organization and function required for a formal Decision."
+        )
+    if str(getattr(assignment, "tenant_id", "")) != case.reference.tenant_id:
+        return False
+    if str(getattr(assignment, "account_id", "")) != _required_principal_text(
+        principal, "account_id"
+    ):
+        return False
+    if str(getattr(assignment, "function_id", "")) != function.object_id:
+        return False
+    if str(getattr(assignment, "organization_unit_id", "")) != organization.object_id:
+        return False
+    if str(getattr(assignment, "status", "active")) != "active":
+        return False
+    valid_from = getattr(assignment, "valid_from", None)
+    valid_until = getattr(assignment, "valid_until", None)
+    return not (
+        (valid_from is not None and effective_at < valid_from)
+        or (valid_until is not None and effective_at >= valid_until)
+    )
+
+
+def _decision_registry(registry: object | None) -> DecisionRegistry:
+    provider = _capability(registry, CAPABILITY_DECISION_REGISTRY)
+    if not isinstance(provider, DecisionRegistry):
+        raise CaseDecisionUnavailable(
+            "Formal Decisions require an enabled Decision registry."
+        )
+    return provider
+
+
+def _decision_id(case: CaseRecord, idempotency_key: str) -> str:
+    return str(
+        uuid.uuid5(
+            _DECISION_NAMESPACE,
+            ":".join(
+                (
+                    case.reference.tenant_id,
+                    case.reference.object_id,
+                    str(case.revision),
+                    idempotency_key.strip(),
+                )
+            ),
+        )
+    )
+
+
+def _validate_command(command: CaseDecisionCommand) -> None:
+    for value, label in (
+        (command.decision_type, "Decision type"),
+        (command.operative_result, "Operative result"),
+        (command.reasoning, "Decision reasoning"),
+        (command.change_reason, "Decision change reason"),
+        (command.idempotency_key, "Decision idempotency key"),
+    ):
+        if not value.strip():
+            raise CaseDecisionError(f"{label} is required.")
+    if command.expected_case_revision < 1:
+        raise CaseDecisionError("Expected Case revision must be positive.")
+    if command.effective_at.tzinfo is None or command.effective_at.utcoffset() is None:
+        raise CaseDecisionError("Decision effective_at must include a timezone.")
+
+
+def _capability(registry: object | None, name: str) -> object | None:
+    if (
+        registry is None
+        or not hasattr(registry, "has_capability")
+        or not hasattr(registry, "capability")
+        or not registry.has_capability(name)
+    ):
+        return None
+    return registry.capability(name)
+
+
+def _text(value: object | None) -> str | None:
+    normalized = str(value or "").strip()
+    return normalized or None
+
+
+def _required_principal_text(principal: object, name: str) -> str:
+    value = _text(getattr(principal, name, None))
+    if value is None:
+        raise PermissionError(f"The current principal has no {name.replace('_', ' ')}.")
+    return value
+
+
+__all__ = [
+    "CaseDecisionCommand",
+    "CaseDecisionError",
+    "CaseDecisionPath",
+    "CaseDecisionResult",
+    "CaseDecisionUnavailable",
+    "DECISION_READ_SCOPE",
+    "DECISION_SENSITIVE_READ_SCOPE",
+    "DECISION_WRITE_SCOPE",
+]

src/govoplan_cases/backend/manifest.py

@@ -6,7 +6,12 @@ from govoplan_core.core.module_guards import (
     drop_table_retirement_provider,
     persistent_table_uninstall_guard,
 )
-from govoplan_core.core.institutional import CAPABILITY_PARTY_RESOLVER
+from govoplan_core.core.access import CAPABILITY_ACCESS_SEMANTIC_DIRECTORY
+from govoplan_core.core.institutional import (
+    CAPABILITY_DECISION_REGISTRY,
+    CAPABILITY_MANDATE_RESOLVER,
+    CAPABILITY_PARTY_RESOLVER,
+)
 from govoplan_core.core.modules import (
     CapabilityDocumentation,
     DocumentationCondition,
@@ -24,6 +29,7 @@ from govoplan_core.core.modules import (
     RoleTemplate,
 )
 from govoplan_core.core.views import ViewSurface
+from govoplan_core.core.search import SearchSourceProviderRegistration
 from govoplan_core.core.provider_governance import (
     ModuleArchitectureDeclaration,
     ModuleArchitectureDocumentation,
@@ -51,6 +57,7 @@ from govoplan_cases.backend.record_source import (
     CAPABILITY_RECORD_SOURCE_CASES,
     create_cases_record_source,
 )
+from govoplan_cases.backend.search_source import create_cases_search_source
 from govoplan_core.db.base import Base
 
 
@@ -138,7 +145,12 @@ manifest = ModuleManifest(
         "workflow_engine",
         "records",
     ),
-    optional_capabilities=(CAPABILITY_PARTY_RESOLVER,),
+    optional_capabilities=(
+        CAPABILITY_PARTY_RESOLVER,
+        CAPABILITY_ACCESS_SEMANTIC_DIRECTORY,
+        CAPABILITY_MANDATE_RESOLVER,
+        CAPABILITY_DECISION_REGISTRY,
+    ),
     permissions=(
         _permission(READ_SCOPE, "View cases", "Read tenant cases and their governed history."),
         _permission(CREATE_SCOPE, "Create cases", "Open a case from a configured case type or service intake."),
@@ -282,6 +294,14 @@ manifest = ModuleManifest(
                 parent_id="cases.detail",
                 order=60,
             ),
+            ViewSurface(
+                id="cases.detail.decision",
+                module_id=MODULE_ID,
+                kind="action",
+                label="Prepare formal decision",
+                parent_id="cases.detail",
+                order=70,
+            ),
         ),
     ),
     provides_interfaces=(
@@ -295,6 +315,8 @@ manifest = ModuleManifest(
         ModuleInterfaceRequirement(name="services.definition", version_min="0.1.0", version_max_exclusive="0.2.0", optional=True),
         ModuleInterfaceRequirement(name="parties.procedure", version_min="0.1.0", version_max_exclusive="0.2.0", optional=True),
         ModuleInterfaceRequirement(name="parties.representation", version_min="0.1.0", version_max_exclusive="0.2.0", optional=True),
+        ModuleInterfaceRequirement(name="mandates.resolution", version_min="0.1.0", version_max_exclusive="0.2.0", optional=True),
+        ModuleInterfaceRequirement(name="decisions.formal_outcome", version_min="0.1.0", version_max_exclusive="0.2.0", optional=True),
     ),
     capability_factories={
         CAPABILITY_CASES_SERVICE_INTAKE: _service_intake,
@@ -358,8 +380,57 @@ manifest = ModuleManifest(
         ),
     ),
     resource_acl_providers=(CaseAclProvider(),),
+    search_sources=(
+        SearchSourceProviderRegistration(
+            id="cases.cases",
+            factory=create_cases_search_source,
+        ),
+    ),
     tenant_summary_providers=(_tenant_summary,),
     documentation=(
+        DocumentationTopic(
+            id="cases.workflow.record-formal-decision",
+            title="Record a formal Decision from a Case",
+            summary="Revalidate acting authority and preserve an exact Decision revision in the Case history.",
+            body=(
+                "The Case detail action accepts only the operative result, reasoning, conditions, effective time, and change reason. "
+                "Cases resolves the exact Case revision, verifies object update access, resolves the current acting assignment through "
+                "Access, and requires exactly one effective Mandate for cases.formal_decision and the selected Decision type. It then "
+                "records the outcome through the optional Decisions registry and links the exact Decision revision to a new Case revision "
+                "in the same database transaction. A replay uses a deterministic Decision identifier; changed replay payloads fail closed."
+            ),
+            layer="configured",
+            documentation_types=("admin", "user"),
+            audience=("case_manager", "decision_officer", "operator", "auditor"),
+            related_modules=("access", "mandates", "decisions", "records"),
+            order=14,
+            conditions=(
+                DocumentationCondition(
+                    required_modules=("cases", "access", "mandates", "decisions"),
+                    required_scopes=("cases:case:update", "decisions:decision:write"),
+                ),
+            ),
+            links=(
+                DocumentationLink(label="Cases", href="/cases", kind="runtime"),
+                DocumentationLink(label="Cases concept", href="govoplan-cases/docs/CONCEPT.md", kind="repository"),
+                DocumentationLink(label="Decisions domain", href="govoplan-decisions/docs/DECISIONS_DOMAIN.md", kind="repository"),
+            ),
+            metadata={
+                "kind": "workflow",
+                "help_contexts": ["cases.action.decide", "cases.decision.editor"],
+                "prerequisites": [
+                    "The Case has an exact responsible organization, function, evidence, and legal-basis version.",
+                    "An active acting assignment and exactly one effective Mandate authorize the Decision type.",
+                ],
+                "steps": [
+                    "Open the Case and select the appropriate acting assignment in the title bar.",
+                    "Record the operative result, reasoning, optional conditions, effective time, and change reason.",
+                    "Confirm the exact Decision and Case revisions in the Case timeline.",
+                    "When Records is enabled, file the exact Decision or Case revision into the destination eAkte.",
+                ],
+                "outcome": "The formal outcome is Decisions-owned and exact-version linked from the Case.",
+            },
+        ),
         DocumentationTopic(
             id="cases.workflow.file-exact-revision",
             title="File an exact case revision into an eAkte",
@@ -412,7 +483,10 @@ manifest = ModuleManifest(
                 "intake retains the exact Service, Mandate, jurisdiction, legal basis, form, "
                 "workflow, and result bindings. Procedure parties come from an optional provider "
                 "or a limited Cases-only compatibility projection. Assignment, evidence, Decision, "
-                "and record links remain stable references owned by their source modules."
+                "and record links remain stable references owned by their source modules. When "
+                "Search is enabled, Cases contributes a rebuildable metadata-only projection. "
+                "Evidence and protected Decision content are excluded, and every candidate is "
+                "rechecked against current Case access before disclosure."
             ),
             layer="available",
             documentation_types=("admin", "user"),
@@ -428,6 +502,7 @@ manifest = ModuleManifest(
                 "help_contexts": [
                     "cases.list",
                     "cases.detail",
+                    "cases.search.result",
                     "cases.state.read-only",
                     "cases.state.restricted",
                 ],

src/govoplan_cases/backend/router.py

@@ -32,6 +32,7 @@ from govoplan_cases.backend.manifest import (
     UPDATE_SCOPE,
 )
 from govoplan_cases.backend.schemas import (
+    CaseDecisionRequest,
     CaseHistoryResponse,
     CaseListResponse,
     CaseStatusWriteRequest,
@@ -40,6 +41,15 @@ from govoplan_cases.backend.schemas import (
     CaseUpdateRequest,
     CaseWriteRequest,
 )
+from govoplan_cases.backend.decision_path import (
+    CaseDecisionCommand,
+    CaseDecisionError,
+    CaseDecisionPath,
+    CaseDecisionUnavailable,
+    DECISION_READ_SCOPE,
+    DECISION_SENSITIVE_READ_SCOPE,
+    DECISION_WRITE_SCOPE,
+)
 from govoplan_cases.backend.service import (
     CaseStoreError,
     can_access_case,
@@ -66,7 +76,9 @@ def _require(principal: ApiPrincipal, scope: str) -> None:
 def _error(exc: Exception) -> HTTPException:
     message = str(exc)
     lowered = message.casefold()
-    if isinstance(exc, LookupError):
+    if isinstance(exc, CaseDecisionUnavailable):
+        code = status.HTTP_424_FAILED_DEPENDENCY
+    elif isinstance(exc, LookupError):
         code = 404
     elif isinstance(exc, PermissionError):
         code = 403
@@ -206,6 +218,78 @@ def api_create_case(
     return item.to_dict()
 
 
+@router.get("/{case_id}/decisions", response_model=dict[str, list[dict[str, Any]]])
+def api_case_decisions(
+    case_id: str,
+    session: Session = Depends(get_session),
+    principal: ApiPrincipal = Depends(get_api_principal),
+) -> dict[str, list[dict[str, Any]]]:
+    _require(principal, READ_SCOPE)
+    _require(principal, DECISION_READ_SCOPE)
+    try:
+        items = CaseDecisionPath(get_registry()).linked(
+            session,
+            principal,
+            case_id=case_id,
+        )
+    except (
+        CaseDecisionError,
+        InstitutionalContextError,
+        LookupError,
+        PermissionError,
+    ) as exc:
+        raise _error(exc) from exc
+    disclose = has_scope(principal, DECISION_SENSITIVE_READ_SCOPE)
+    return {
+        "decisions": [
+            item.to_dict(include_protected=disclose)
+            for item in items
+        ]
+    }
+
+
+@router.post(
+    "/{case_id}/decisions",
+    response_model=dict[str, Any],
+    status_code=status.HTTP_201_CREATED,
+)
+def api_record_case_decision(
+    case_id: str,
+    payload: CaseDecisionRequest,
+    session: Session = Depends(get_session),
+    principal: ApiPrincipal = Depends(get_api_principal),
+) -> dict[str, Any]:
+    _require(principal, UPDATE_SCOPE)
+    _require(principal, DECISION_WRITE_SCOPE)
+    try:
+        result = CaseDecisionPath(get_registry()).record(
+            session,
+            principal,
+            case_id=case_id,
+            command=CaseDecisionCommand(
+                expected_case_revision=payload.expected_case_revision,
+                effective_at=payload.effective_at,
+                decision_type=payload.decision_type,
+                operative_result=payload.operative_result,
+                reasoning=payload.reasoning,
+                conditions=tuple(payload.conditions),
+                change_reason=payload.change_reason,
+                idempotency_key=payload.idempotency_key,
+            ),
+        )
+        session.commit()
+    except (
+        CaseDecisionError,
+        InstitutionalContextError,
+        LookupError,
+        PermissionError,
+        ValueError,
+    ) as exc:
+        session.rollback()
+        raise _error(exc) from exc
+    return result.to_dict()
+
+
 @router.get("/{case_id}", response_model=dict[str, Any])
 def api_get_case(
     case_id: str,

src/govoplan_cases/backend/schemas.py

@@ -82,6 +82,19 @@ class CaseUpdateRequest(BaseModel):
     metadata: dict[str, Any] | None = None
 
 
+class CaseDecisionRequest(BaseModel):
+    model_config = ConfigDict(extra="forbid")
+
+    expected_case_revision: int = Field(ge=1)
+    effective_at: datetime
+    decision_type: str = Field(min_length=1, max_length=120)
+    operative_result: str = Field(min_length=1, max_length=20_000)
+    reasoning: str = Field(min_length=1, max_length=50_000)
+    conditions: list[str] = Field(default_factory=list, max_length=100)
+    change_reason: str = Field(min_length=1, max_length=1_000)
+    idempotency_key: str = Field(min_length=1, max_length=255)
+
+
 class CaseListResponse(BaseModel):
     cases: list[dict[str, Any]]
     total: int
@@ -99,6 +112,7 @@ class CaseTimelineResponse(BaseModel):
 
 __all__ = [
     "CaseGrantRequest",
+    "CaseDecisionRequest",
     "CaseHistoryResponse",
     "CaseListResponse",
     "CaseStatusWriteRequest",

src/govoplan_cases/backend/search_source.py

@@ -0,0 +1,283 @@
+from __future__ import annotations
+
+from collections.abc import Mapping, Sequence
+from urllib.parse import quote
+
+from sqlalchemy import func, select
+from sqlalchemy.orm import Session
+
+from govoplan_core.auth import ApiPrincipal
+from govoplan_core.core.events import PlatformEvent
+from govoplan_core.core.modules import ModuleContext
+from govoplan_core.core.search import (
+    SearchAuthorizationRequest,
+    SearchBackfillPage,
+    SearchBackfillRequest,
+    SearchDocument,
+    SearchIndexChange,
+    SearchResourceReference,
+    SearchResourceType,
+)
+from govoplan_cases.backend.db.models import (
+    CaseAccessGrant,
+    CaseIdentity,
+    CaseRecordRevision,
+)
+from govoplan_cases.backend.service import can_access_case
+
+
+PROVIDER_ID = "cases.cases"
+RESOURCE_TYPE = "case"
+READ_SCOPE = "cases:case:read"
+ADMIN_SCOPE = "cases:case:admin"
+
+
+class CasesSearchSource:
+    def resource_types(self) -> Sequence[SearchResourceType]:
+        return (
+            SearchResourceType(
+                provider_id=PROVIDER_ID,
+                module_id="cases",
+                resource_type=RESOURCE_TYPE,
+                label="Cases",
+                requires_authorization_recheck=True,
+            ),
+        )
+
+    def backfill(
+        self,
+        session: object,
+        *,
+        request: SearchBackfillRequest,
+    ) -> SearchBackfillPage:
+        _assert_source(request.provider_id, request.resource_type)
+        db = _session(session)
+        statement = (
+            select(CaseRecordRevision, CaseIdentity)
+            .join(CaseIdentity, CaseIdentity.id == CaseRecordRevision.identity_id)
+            .where(
+                CaseRecordRevision.tenant_id == request.tenant_id,
+                CaseRecordRevision.superseded_at.is_(None),
+            )
+        )
+        if request.cursor:
+            statement = statement.where(CaseRecordRevision.case_id > request.cursor)
+        rows = list(
+            db.execute(
+                statement.order_by(CaseRecordRevision.case_id).limit(request.limit + 1)
+            ).all()
+        )
+        has_more = len(rows) > request.limit
+        selected = rows[: request.limit]
+        grants = _grants_by_case(
+            db,
+            request.tenant_id,
+            [row.case_id for row, _identity in selected],
+        )
+        high_watermark = db.scalar(
+            select(func.max(CaseRecordRevision.recorded_at)).where(
+                CaseRecordRevision.tenant_id == request.tenant_id,
+                CaseRecordRevision.superseded_at.is_(None),
+            )
+        )
+        return SearchBackfillPage(
+            documents=tuple(
+                _document(
+                    row,
+                    identity=identity,
+                    grants=grants.get(row.case_id, ()),
+                )
+                for row, identity in selected
+            ),
+            next_cursor=selected[-1][0].case_id if has_more and selected else None,
+            complete=not has_more,
+            high_watermark=high_watermark.isoformat() if high_watermark else None,
+        )
+
+    def authorize(
+        self,
+        session: object,
+        principal: object,
+        *,
+        requests: Sequence[SearchAuthorizationRequest],
+    ) -> Mapping[str, bool]:
+        decisions = {item.reference.key: False for item in requests}
+        if not isinstance(principal, ApiPrincipal) or not principal.has(READ_SCOPE):
+            return decisions
+        db = _session(session)
+        for request in requests:
+            reference = request.reference
+            if (
+                reference.tenant_id != principal.tenant_id
+                or reference.module_id != "cases"
+                or reference.resource_type != RESOURCE_TYPE
+            ):
+                continue
+            decisions[reference.key] = can_access_case(
+                db,
+                principal,
+                case_id=reference.resource_id,
+                permission="read",
+            )
+        return decisions
+
+    def index_changes_for_event(
+        self,
+        session: object,
+        *,
+        event: PlatformEvent,
+        delivery_key: str,
+    ) -> Sequence[SearchIndexChange]:
+        if (
+            event.module_id != "cases"
+            or event.tenant is None
+            or event.resource is None
+            or event.resource.type != RESOURCE_TYPE
+            or event.resource.id is None
+        ):
+            return ()
+        db = _session(session)
+        row = db.scalar(
+            select(CaseRecordRevision).where(
+                CaseRecordRevision.tenant_id == event.tenant.id,
+                CaseRecordRevision.case_id == event.resource.id,
+                CaseRecordRevision.superseded_at.is_(None),
+            )
+        )
+        identity = db.scalar(
+            select(CaseIdentity).where(
+                CaseIdentity.tenant_id == event.tenant.id,
+                CaseIdentity.case_id == event.resource.id,
+            )
+        )
+        deleted = row is None or identity is None
+        cursor = event.event_id
+        document = None
+        if not deleted:
+            document = _document(
+                row,
+                identity=identity,
+                grants=_grants_by_case(
+                    db,
+                    event.tenant.id,
+                    [row.case_id],
+                ).get(row.case_id, ()),
+                change_cursor=cursor,
+            )
+        reference = SearchResourceReference(
+            tenant_id=event.tenant.id,
+            module_id="cases",
+            resource_type=RESOURCE_TYPE,
+            resource_id=event.resource.id,
+        )
+        return (
+            SearchIndexChange(
+                change_id=f"{delivery_key}:{PROVIDER_ID}",
+                provider_id=PROVIDER_ID,
+                kind="delete" if deleted else "upsert",
+                reference=reference,
+                source_revision=(document.source_revision if document else cursor),
+                cursor=cursor,
+                document=document,
+                occurred_at=event.occurred_at,
+            ),
+        )
+
+
+def create_cases_search_source(_context: ModuleContext) -> CasesSearchSource:
+    return CasesSearchSource()
+
+
+def _document(
+    row: CaseRecordRevision,
+    *,
+    identity: CaseIdentity,
+    grants: Sequence[CaseAccessGrant],
+    change_cursor: str | None = None,
+) -> SearchDocument:
+    tokens = [f"scope:{READ_SCOPE}", f"scope:{ADMIN_SCOPE}"]
+    if identity.created_by:
+        tokens.extend(
+            (f"account:{identity.created_by}", f"membership:{identity.created_by}")
+        )
+    prefixes = {
+        "account": "account",
+        "identity": "identity",
+        "group": "group",
+        "role": "role",
+        "function": "function",
+        "function_assignment": "function",
+    }
+    for grant in grants:
+        prefix = prefixes.get(grant.subject_kind)
+        if prefix:
+            tokens.append(f"{prefix}:{grant.subject_id}")
+    return SearchDocument(
+        tenant_id=row.tenant_id,
+        module_id="cases",
+        provider_id=PROVIDER_ID,
+        resource_type=RESOURCE_TYPE,
+        resource_id=row.case_id,
+        title=row.title,
+        url=f"/cases/{quote(row.case_id, safe='')}",
+        summary=f"{identity.case_number} - {row.status_key}",
+        body=row.search_text[:200_000],
+        keywords=(
+            identity.case_number[:200],
+            row.case_type_key[:200],
+            row.status_key[:200],
+        ),
+        visibility="restricted",
+        acl_tokens=tuple(dict.fromkeys(tokens)),
+        metadata={
+            "case_number": identity.case_number,
+            "case_type_key": row.case_type_key,
+            "status_key": row.status_key,
+            "access_mode": row.access_mode,
+        },
+        source_revision=str(row.revision),
+        change_cursor=change_cursor,
+        source_updated_at=row.recorded_at,
+        requires_authorization_recheck=True,
+    )
+
+
+def _grants_by_case(
+    session: Session,
+    tenant_id: str,
+    case_ids: Sequence[str],
+) -> dict[str, tuple[CaseAccessGrant, ...]]:
+    grouped: dict[str, list[CaseAccessGrant]] = {
+        case_id: [] for case_id in case_ids
+    }
+    if not case_ids:
+        return {}
+    rows = session.scalars(
+        select(CaseAccessGrant).where(
+            CaseAccessGrant.tenant_id == tenant_id,
+            CaseAccessGrant.case_id.in_(tuple(case_ids)),
+            CaseAccessGrant.active.is_(True),
+        )
+    )
+    for row in rows:
+        grouped.setdefault(row.case_id, []).append(row)
+    return {key: tuple(value) for key, value in grouped.items()}
+
+
+def _assert_source(provider_id: str, resource_type: str) -> None:
+    if provider_id != PROVIDER_ID or resource_type != RESOURCE_TYPE:
+        raise ValueError("Unsupported Cases search source.")
+
+
+def _session(value: object) -> Session:
+    if not isinstance(value, Session):
+        raise TypeError("Cases search requires a SQLAlchemy session.")
+    return value
+
+
+__all__ = [
+    "CasesSearchSource",
+    "PROVIDER_ID",
+    "RESOURCE_TYPE",
+    "create_cases_search_source",
+]

src/govoplan_cases/backend/service.py

@@ -331,6 +331,8 @@ def create_case_from_intake(
             "result_refs": list(plan.result_refs),
             "required_evidence_types": list(plan.required_evidence_types),
             "deadline_refs": list(plan.deadline_refs),
+            "remedy_refs": list(plan.remedy_refs),
+            "service_level_refs": list(plan.service_level_refs),
         },
     )
     return create_case(

src/govoplan_cases/backend/service_intake.py

@@ -26,6 +26,8 @@ class CaseIntakePlan:
     result_refs: tuple[str, ...] = ()
     required_evidence_types: tuple[str, ...] = ()
     deadline_refs: tuple[str, ...] = ()
+    remedy_refs: tuple[str, ...] = ()
+    service_level_refs: tuple[str, ...] = ()
 
 
 class CaseServiceIntake:
@@ -91,6 +93,8 @@ class CaseServiceIntake:
             result_refs=_binding_refs(definition, "result"),
             required_evidence_types=definition.required_evidence_types,
             deadline_refs=definition.deadline_refs,
+            remedy_refs=definition.remedy_refs,
+            service_level_refs=definition.service_level_refs,
         )