diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0e6a815..4bfd821 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ All notable changes to this repository. Dates are UTC.
 ## [2026-09-09]
 
 ### Added
+- **PR #164** — docs: added `deliverables/ai-gateway-architecture-review/` — systematic AI Gateway architecture review focused on resilience & cost control, plus `deliverables/README.md` index update.
 - **PR #165** — deliverables: added `deliverables/onspace-ai/` (FastAPI cost+reliability stack — Redis/memory fail-open cache, circuit breaker, fallback router, token budget + context compiler, Prometheus metrics, k8s manifests; 31 tests), `deliverables/manus-client/` (Manus REST API v2 async client on dot-notation endpoints `task.create`/`task.listMessages`; 10 tests), `deliverables/firecrawl-fastapi/` (FireCrawl + FastAPI production scraper/crawler, firecrawl-py <2.0.0 v1.x surface; 6 tests). All no workflow files, runnable via mock/fail-open.
 - **PR #155** — scaffold: added the ZyntroAI merged monorepo scaffold as additive (no-clobber) new files — FastAPI/SQLModel async backend (JWT auth, Alembic, Item CRUD, 6 passing tests), React+Vite+TS frontend, Obsidian↔Algolia knowledge indexer, k8s manifests, 6 typed PR templates, and spec docs. No existing main file modified.
 - **PR #160** — docs: rewrote `README.md` to reflect the actual repo structure (OAuth2 PKCE FastAPI core, `graphql_api/`, `skills/`, `deliverables/`, `docs/`, `helm/` + `k8s/`, `tests/`), replacing the stale self-referential comparison doc.