# Sprint 124 - Policy & Reasoning

_Last updated: November 8, 2025. Implementation order is DOING → TODO → BLOCKED._

Focus areas below were split out of the previous combined sprint; execute sections in order unless noted.

## Policy.II
Dependency: Sprint 120.C - Policy.I (must land before this track).
Focus: Policy & Reasoning focus on Policy (phase II).

| # | Task ID & handle | State | Key dependency / next step | Owners |
| --- | --- | --- | --- | --- |
| P1 | PREP-POLICY-ENGINE-20-002-BUILD-DETERMINISTIC | DONE (2025-11-20) | Prep doc at `docs/modules/policy/prep/2025-11-20-policy-engine-20-002-prep.md`; captures evaluator constraints. | Policy Guild / src/Policy/StellaOps.Policy.Engine | Build deterministic evaluator honoring lexical/priority order, first-match semantics, and safe value types (no wall-clock/network access). <br><br> Document artefact/deliverable for POLICY-ENGINE-20-002 and publish location so downstream tasks can proceed. |
| 1 | POLICY-CONSOLE-23-002 | TODO | Produce simulation diff metadata (before/after counts, severity deltas, rule impact summaries) and approval state endpoints consumed by Console policy workspace; expose RBAC-aware status transitions (Deps: POLICY-CONSOLE-23-001) | Policy Guild, Product Ops / src/Policy/StellaOps.Policy.Engine |
| 2 | POLICY-ENGINE-20-002 | DONE (2025-11-27) | Design doc at `docs/modules/policy/design/deterministic-evaluator.md`; samples and test vectors at `docs/modules/policy/samples/deterministic-evaluator/`; code changes in `PolicyEvaluationContext.cs` and `PolicyExpressionEvaluator.cs` | Policy Guild / src/Policy/StellaOps.Policy.Engine |
| 3 | POLICY-ENGINE-20-003 | DONE (2025-11-27) | SelectionJoin models, PurlEquivalence table, and SelectionJoinService implemented in `src/Policy/StellaOps.Policy.Engine/SelectionJoin/` | Policy Guild, Concelier Core Guild, Excititor Core Guild / src/Policy/StellaOps.Policy.Engine |
| 4 | POLICY-ENGINE-20-004 | DONE (2025-11-27) | Materialization writer implemented in `src/Policy/StellaOps.Policy.Engine/Materialization/` with `EffectiveFinding` models, append-only history, tenant scoping, and trace references | Policy Guild, Platform Storage Guild / src/Policy/StellaOps.Policy.Engine |
| 5 | POLICY-ENGINE-20-005 | DONE (2025-11-27) | Determinism guard implemented in `src/Policy/StellaOps.Policy.Engine/DeterminismGuard/` with static analyzer (`ProhibitedPatternAnalyzer`), runtime sandbox (`DeterminismGuardService`, `EvaluationScope`), and guarded evaluator integration (`GuardedPolicyEvaluator`) | Policy Guild, Security Engineering / src/Policy/StellaOps.Policy.Engine |
| 6 | POLICY-ENGINE-20-006 | TODO | Implement incremental orchestrator reacting to advisory/vex/SBOM change streams and scheduling partial policy re-evaluations (Deps: POLICY-ENGINE-20-005) | Policy Guild, Scheduler Worker Guild / src/Policy/StellaOps.Policy.Engine |
| 7 | POLICY-ENGINE-20-007 | TODO | Emit structured traces/logs of rule hits with sampling controls, metrics (`rules_fired_total`, `vex_overrides_total`), and expose explain trace exports (Deps: POLICY-ENGINE-20-006) | Policy Guild, Observability Guild / src/Policy/StellaOps.Policy.Engine |
| 8 | POLICY-ENGINE-20-008 | TODO | Add unit/property/golden/perf suites covering policy compilation, evaluation correctness, determinism, and SLA targets (Deps: POLICY-ENGINE-20-007) | Policy Guild, QA Guild / src/Policy/StellaOps.Policy.Engine |
| 9 | POLICY-ENGINE-20-009 | TODO | Define Mongo schemas/indexes for `policies`, `policy_runs`, and `effective_finding_*`; implement migrations and tenant enforcement (Deps: POLICY-ENGINE-20-008) | Policy Guild, Storage Guild / src/Policy/StellaOps.Policy.Engine |
| 10 | POLICY-ENGINE-27-001 | TODO | Extend compile outputs to include rule coverage metadata, symbol table, inline documentation, and rule index for editor autocomplete; persist deterministic hashes (Deps: POLICY-ENGINE-20-009) | Policy Guild / src/Policy/StellaOps.Policy.Engine |
| 11 | POLICY-ENGINE-27-002 | TODO | Enhance simulate endpoints to emit rule firing counts, heatmap aggregates, sampled explain traces with deterministic ordering, and delta summaries for quick/batch sims (Deps: POLICY-ENGINE-27-001) | Policy Guild, Observability Guild / src/Policy/StellaOps.Policy.Engine |
| 12 | POLICY-ENGINE-29-001 | TODO | Implement batch evaluation endpoint (`POST /policy/eval/batch`) returning determinations + rationale chain for sets of `(artifact,purl,version,advisory)` tuples; support pagination and cost budgets (Deps: POLICY-ENGINE-27-004) | Policy Guild / src/Policy/StellaOps.Policy.Engine |
| 13 | POLICY-ENGINE-27-004 | DONE (2025-10-19) | Completed in Sprint 120; see archived tasks note. | Policy Guild / src/Policy/StellaOps.Policy.Engine | Update golden/property tests to cover coverage metadata, symbol tables, explain traces, and complexity limits; provide fixtures for Registry/Console integration. |
| 13 | POLICY-ENGINE-29-002 | TODO | Provide streaming simulation API comparing two policy versions, returning per-finding deltas without writes; align determinism with Vuln Explorer simulation (Deps: POLICY-ENGINE-29-001) | Policy Guild, Findings Ledger Guild / src/Policy/StellaOps.Policy.Engine |

## Execution Log
| Date (UTC) | Update | Owner |
| --- | --- | --- |
| 2025-11-27 | POLICY-ENGINE-20-005: Completed determinism guard - `DeterminismViolation.cs` (violation models/options), `ProhibitedPatternAnalyzer.cs` (static analysis with regex patterns for DateTime.Now, Random, Guid.NewGuid, HttpClient, File.Read, etc.), `DeterminismGuardService.cs` (runtime sandbox with EvaluationScope, DeterministicTimeProvider), `GuardedPolicyEvaluator.cs` (integration layer). Status → DONE. | Implementer |
| 2025-11-27 | POLICY-ENGINE-20-004: Completed materialization writer - `EffectiveFindingModels.cs` (document schema), `EffectiveFindingWriter.cs` (upsert + append-only history). Tenant-scoped collections, trace references, content hash deduplication. Status → DONE. | Implementer |
| 2025-11-27 | POLICY-ENGINE-20-003: Completed selection joiners - `SelectionJoinModels.cs` (tuple models), `PurlEquivalence.cs` (equivalence table with package key extraction), `SelectionJoinService.cs` (deterministic batching, multi-index lookup). Status → DONE. | Implementer |
| 2025-11-27 | POLICY-ENGINE-20-002: Completed. Created design doc, sample config, test vectors. Added `EvaluationTimestamp`/`now` for deterministic timestamps. Status → DONE. | Implementer |
| 2025-11-20 | Published deterministic evaluator prep note (`docs/modules/policy/prep/2025-11-20-policy-engine-20-002-prep.md`); set PREP-POLICY-ENGINE-20-002 to DONE. | Implementer |
| 2025-11-19 | Assigned PREP owners/dates; see Delivery Tracker. | Planning |
| 2025-11-25 | Reconciled POLICY-ENGINE-27-004 as DONE (completed 2025-10-19 in Sprint 120); added to Delivery Tracker for traceability. | Project Mgmt |