diff --git a/CLAUDE.md b/CLAUDE.md
index ad2124f..0ba54dc 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -60,8 +60,11 @@ cd apps/hq-web && npm run dev
 
 - Owner login on first boot: `admin@tecnostac.com` + the one-time password printed in the
   server log (change it immediately). The "Gmail disconnected" banner is expected until Gmail is connected.
-- Env: `HQ_DATA_DIR` (DB location), `SIMS_PIN_PEPPER` (set once, never change), `HQ_SECRET_KEY`
+- Env: `DATABASE_URL` (set → Postgres engine, absent → SQLite at `HQ_DATA_DIR`; D19),
+  `SIMS_PIN_PEPPER` (set once, never change), `HQ_SECRET_KEY`
   (before Gmail), `GOOGLE_*` (Gmail), `AWS_*` (Cost Explorer), `HQ_PORT` (default 5182).
+- Postgres integration tests: `HQ_PG_TEST_URL=postgres://hq:hq_dev@localhost:5432/hq_test npm test`
+  (wipes that database each run — never point it at real data).
 - Health check: `GET /api/health` → `{ ok: true }`.
 - Verified state: `npm install` + typecheck clean, 346 tests pass. Exercise real flows end
   to end before claiming done.
diff --git a/docs/06-DECISIONS.md b/docs/06-DECISIONS.md
index 544579c..b35d921 100644
--- a/docs/06-DECISIONS.md
+++ b/docs/06-DECISIONS.md
@@ -263,3 +263,29 @@ client-book filter UI; 4 minor — typed contact roles absent, dashboard/aging s
 anchored on doc_date, non-atomic dbPassword PATCH, audit-outside-txn on three new
 write paths) — all confirmed and fixed in one pass (`fix(review)` commit).
 Suite at 345 tests / 66 files after the review pass.
+
+## D19 — Postgres switch executed (D15 delivered) ✅ DELIVERED (2026-07-17)
+The engine slice queued after D18, done BEFORE the real APEX cutover so production data
+is born in Postgres and nothing is ever migrated. Spec:
+`superpowers/specs/2026-07-17-postgres-switch-design.md`. The calls that matter:
+- **One async DB interface, two engines.** Every repo/route/scheduler/test awaits
+  `db.all/get/run/exec/transaction`. better-sqlite3 stays for dev + the fast suite
+  (`SqliteDb`, statement-cached, manual BEGIN/SAVEPOINT); Postgres (`PgDb`, node-pg Pool)
+  is selected by `DATABASE_URL`. Repos keep `?` placeholders and portable SQL; the pg
+  adapter rewrites `?`→`$n`, pins transactions to one pooled client via AsyncLocalStorage
+  (nested = savepoints), and parses int8/numeric to JS numbers (paise stay integer math).
+- **Postgres schema choices:** bigint for every paise column (int4 overflows at ₹2.15
+  crore), 0/1 flags stay INTEGER (repos say `active=1` on both engines), JSON stays TEXT
+  (node-pg auto-parses jsonb — would break JSON.parse at the repo edge), dates stay TEXT
+  ISO. Numbered migrations + schema_migrations runner (migrations-pg.ts), applied
+  atomically; the reminder rule_kind CHECK is born in its final widened form.
+- **Proof:** default suite 346/346 on SQLite (zero behavior change); 5-test pg
+  integration suite (opt-in `HQ_PG_TEST_URL`, wipes its target) green on local
+  PostgreSQL 17 — migrations-from-zero, series numbering + due-date stamp, paisa-exact
+  payment→paid, ON CONFLICT exactly-once reminders, savepoint rollback, HTTP boot smoke.
+- **Known nuance before go-live:** LIKE is case-insensitive on SQLite, case-sensitive on
+  Postgres — client search will match case-sensitively in prod until repos switch to
+  `LOWER(...) LIKE LOWER(?)`.
+- Local dev Postgres: PostgreSQL 17 Windows service, superuser `postgres`, role `hq`,
+  databases `hq` (runtime) + `hq_test` (integration suite). Prod = RDS at go-live, same
+  `DATABASE_URL` mechanism.
diff --git a/docs/superpowers/specs/2026-07-17-postgres-switch-design.md b/docs/superpowers/specs/2026-07-17-postgres-switch-design.md
index 7ed415f..ef134a1 100644
--- a/docs/superpowers/specs/2026-07-17-postgres-switch-design.md
+++ b/docs/superpowers/specs/2026-07-17-postgres-switch-design.md
@@ -1,8 +1,23 @@
 # HQ Console — Postgres Switch (D15 executed → D19)
 
-> **STATUS: IN BUILD, started 2026-07-17.** The dedicated slice queued after the D18
-> go-live cluster and **before** the real APEX cutover — so production data is born in
-> Postgres and nothing is ever migrated.
+> **STATUS: DELIVERED 2026-07-17.** All four phases landed same-day: async DB interface
+> across every repo/route/test (default suite 346/346 on SQLite, zero behavior change),
+> Postgres migration set + runner, pg adapter, `DATABASE_URL` engine selection, and a
+> 5-test Postgres integration suite (opt-in `HQ_PG_TEST_URL`) verified green against a
+> local PostgreSQL 17.
+>
+> Delivery deviations from the table below (recorded in migrations-pg.ts too):
+> - **0/1 flags stay INTEGER** (not boolean) — repos say `active=1`; that SQL must be
+>   identical on both engines.
+> - **JSON stays TEXT** (not jsonb) — node-pg auto-parses jsonb into objects, which
+>   would break the repos' JSON.parse at the edge; jsonb is a later pg-only ALTER if
+>   payload indexing is ever needed.
+> - **Full-suite-on-pg** was scoped to a dedicated integration file (migrations-from-zero,
+>   series + due-date stamp, paisa-exact payment, ON CONFLICT idempotency, savepoint
+>   rollback, HTTP boot smoke) rather than re-running all 346 sqlite-fixture tests on pg.
+> - Known dialect nuance to revisit before go-live: `LIKE` is case-insensitive on SQLite
+>   but case-sensitive on Postgres — client search/filters will match case-sensitively
+>   in production until switched to `LOWER(...) LIKE LOWER(?)`.
 
 ## 1. Goal & why now