diff --git a/backend/scripts/ingest/backfill_ecos_cycle.py b/backend/scripts/ingest/backfill_ecos_cycle.py
new file mode 100644
index 00000000..1db15b80
--- /dev/null
+++ b/backend/scripts/ingest/backfill_ecos_cycle.py
@@ -0,0 +1,90 @@
+"""ecos_timeseries.cycle 100% NULL 채움.
+
+audit-null-orphan-2026-05-04 발견 — ECOS API ETL 이 ``cycle`` 컬럼 미적재.
+3 stat_code (121Y006/722Y001/901Y009) × ECOS StatisticItemList API 호출 후
+``(stat_code, item_code1)`` 매핑으로 cycle UPDATE.
+
+ECOS API rate limit / pagination:
+- 페이지당 1000 item (901Y009 는 페이지 2 추가 호출 필요)
+- 기준: 2026-05-05 — 901Y009 = 1,743 items (페이지 1+2 합산), 121Y006 = 57, 722Y001 = 48
+
+결과: 0% → 100% (2,783/2,783)
+
+사용법:
+    cd backend && python scripts/ingest/backfill_ecos_cycle.py
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+import httpx
+import sqlalchemy as sa
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[2]))
+from src.config.settings import settings  # noqa: E402
+
+PAGE = 1000
+
+
+def _fetch_meta(stat_code: str, key: str) -> dict[str, str]:
+    """stat_code 의 모든 item 메타 (item_code → cycle) 가져오기. 페이지네이션 포함."""
+    out: dict[str, str] = {}
+    start = 1
+    while True:
+        url = f"http://ecos.bok.or.kr/api/StatisticItemList/{key}/json/kr/{start}/{start + PAGE - 1}/{stat_code}"
+        block = httpx.get(url, timeout=30).json().get("StatisticItemList")
+        if not block or not block.get("row"):
+            break
+        rows = block["row"]
+        for row in rows:
+            ic = row.get("ITEM_CODE")
+            cy = row.get("CYCLE")
+            if ic and cy:
+                out[ic] = cy
+        if len(rows) < PAGE:
+            break
+        start += PAGE
+    return out
+
+
+def main() -> None:
+    key = settings.ecos_api_key
+    if not key:
+        raise RuntimeError("ECOS_API_KEY missing in settings")
+
+    engine = sa.create_engine(settings.postgres_url)
+
+    # DB 의 stat_code distinct
+    with engine.connect() as conn:
+        stat_codes = [r[0] for r in conn.execute(sa.text("SELECT DISTINCT stat_code FROM ecos_timeseries")).fetchall()]
+    print(f"ecos_timeseries stat_codes: {stat_codes}")
+
+    total_updates = 0
+    for sc in stat_codes:
+        meta = _fetch_meta(sc, key)
+        print(f"  {sc}: meta {len(meta)} items")
+        with engine.begin() as conn:
+            updated = 0
+            for ic, cy in meta.items():
+                result = conn.execute(
+                    sa.text(
+                        "UPDATE ecos_timeseries SET cycle=:cy WHERE stat_code=:sc AND item_code1=:ic AND cycle IS NULL"
+                    ),
+                    {"cy": cy, "sc": sc, "ic": ic},
+                )
+                updated += result.rowcount
+            total_updates += updated
+            print(f"    updated: {updated} rows")
+
+    with engine.connect() as conn:
+        n = conn.execute(sa.text("SELECT COUNT(*) FROM ecos_timeseries")).scalar()
+        n_cy = conn.execute(sa.text("SELECT COUNT(*) FROM ecos_timeseries WHERE cycle IS NOT NULL")).scalar()
+    pct = (n_cy / n * 100) if n else 0
+    print()
+    print(f"=== AFTER ===\n  cycle non-NULL: {n_cy}/{n} ({pct:.1f}%) — total update {total_updates}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/backend/scripts/ingest/fill_ttareungi_dong_code.py b/backend/scripts/ingest/fill_ttareungi_dong_code.py
new file mode 100644
index 00000000..0a4a0f6e
--- /dev/null
+++ b/backend/scripts/ingest/fill_ttareungi_dong_code.py
@@ -0,0 +1,95 @@
+"""master_ttareungi_station.dong_code 채우기 (마포 한정).
+
+PR #184 가 ttareungi station 의 lat/lon + sigungu_code 채움 (3,230 row API 매핑).
+본 스크립트는 그 결과 위에서 마포(sigungu_code='11440') station 의 dong_code 를
+``dong_centroid`` 16 동과의 haversine 거리 비교로 매핑.
+
+- 마포 station: 가장 가까운 dong_centroid → dong_code 적용
+- 마포 외 station: 서울 전체 dong_centroid 부재 (E4 한계) — skip
+- ``opened_at`` 컬럼: 따릉이 API 응답에 없음 — skip
+
+사용법:
+    cd backend && python scripts/ingest/fill_ttareungi_dong_code.py
+
+idempotent — dong_code 이미 채워진 row 는 skip.
+"""
+
+from __future__ import annotations
+
+import math
+import sys
+from pathlib import Path
+
+import sqlalchemy as sa
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[2]))
+from src.config.settings import settings  # noqa: E402
+
+
+def _haversine_m(lat1: float, lon1: float, lat2: float, lon2: float) -> float:
+    """두 좌표 간 거리 (미터)."""
+    radius = 6371000  # Earth radius m
+    phi1, phi2 = math.radians(lat1), math.radians(lat2)
+    dphi = math.radians(lat2 - lat1)
+    dlon = math.radians(lon2 - lon1)
+    a = math.sin(dphi / 2) ** 2 + math.cos(phi1) * math.cos(phi2) * math.sin(dlon / 2) ** 2
+    return radius * 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
+
+
+def main() -> None:
+    engine = sa.create_engine(settings.postgres_url)
+
+    with engine.connect() as conn:
+        centroids = conn.execute(
+            sa.text("SELECT dong_code, lat, lon FROM dong_centroid WHERE lat IS NOT NULL")
+        ).fetchall()
+        cents = [(r._mapping["dong_code"], r._mapping["lat"], r._mapping["lon"]) for r in centroids]
+        print(f"dong_centroid: {len(cents)} 동")
+
+        rows = conn.execute(
+            sa.text(
+                "SELECT station_id, lat, lon FROM master_ttareungi_station "
+                "WHERE sigungu_code='11440' AND dong_code IS NULL AND lat IS NOT NULL"
+            )
+        ).fetchall()
+        print(f"마포 ttareungi (dong_code NULL): {len(rows)}")
+
+    matched: list[tuple[str, str]] = []
+    for r in rows:
+        sid = r._mapping["station_id"]
+        lat = r._mapping["lat"]
+        lon = r._mapping["lon"]
+        best = min(cents, key=lambda c: _haversine_m(lat, lon, c[1], c[2]))
+        matched.append((sid, best[0]))
+
+    print(f"matched: {len(matched)}")
+
+    with engine.begin() as conn:
+        for sid, dc in matched:
+            conn.execute(
+                sa.text("UPDATE master_ttareungi_station SET dong_code=:dc WHERE station_id=:sid"),
+                {"dc": dc, "sid": sid},
+            )
+
+    with engine.connect() as conn:
+        total = conn.execute(sa.text("SELECT COUNT(*) FROM master_ttareungi_station")).scalar()
+        null_dc = conn.execute(
+            sa.text("SELECT COUNT(*) FROM master_ttareungi_station WHERE dong_code IS NULL")
+        ).scalar()
+        mapo_filled = conn.execute(
+            sa.text(
+                "SELECT COUNT(*) FROM master_ttareungi_station WHERE sigungu_code='11440' AND dong_code IS NOT NULL"
+            )
+        ).scalar()
+
+    print()
+    print("=== AFTER ===")
+    print(f"  total {total}, dong_code NULL {null_dc} ({null_dc / total * 100:.1f}%)")
+    print(f"  마포 dong_code 채워짐: {mapo_filled}")
+    print()
+    print("미적재 사유 (마포 외 5,298 row):")
+    print("  서울 전체 dong_centroid 부재 (E4 한계). DongCentroid 서울 확장 별 PR 필요.")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/backend/src/config/settings.py b/backend/src/config/settings.py
index 95e2184a..48590044 100644
--- a/backend/src/config/settings.py
+++ b/backend/src/config/settings.py
@@ -41,6 +41,8 @@ class Settings(BaseSettings):
     sgis_secret_key: str = os.getenv("SGIS_SECRET_KEY", "")
     molit_api_key: str = os.getenv("MOLIT_API_KEY", "")
     ftc_api_key: str = os.getenv("FTC_API_KEY", "")
+    kakao_api_key: str = os.getenv("KAKAO_API_KEY", "")
+    ecos_api_key: str = os.getenv("ECOS_API_KEY", "")
     law_oc: str = os.getenv("LAW_OC", "")
 
     # Naver DataLab API
diff --git a/docs/retrospective/2026-05-05.md b/docs/retrospective/2026-05-05.md
index 9999cf88..5e04c208 100644
--- a/docs/retrospective/2026-05-05.md
+++ b/docs/retrospective/2026-05-05.md
@@ -549,3 +549,63 @@
 ```
 
 ---
+
+## 12:31:32 세션 완료
+
+### 변경 파일
+- backend/src/agents/legal/categories.py
+- docs/retrospective/2026-05-05.md
+
+### diff 요약
+```
+ backend/src/agents/legal/categories.py | 18 +++++++++---------
+ docs/retrospective/2026-05-05.md       |  9 +++++++++
+ 2 files changed, 18 insertions(+), 9 deletions(-)
+```
+
+---
+
+## 12:36:12 세션 완료
+
+### 변경 파일
+- backend/src/agents/legal/categories.py
+- docs/retrospective/2026-05-05.md
+
+### diff 요약
+```
+ backend/src/agents/legal/categories.py | 18 +++++++++---------
+ docs/retrospective/2026-05-05.md       | 24 ++++++++++++++++++++++++
+ 2 files changed, 33 insertions(+), 9 deletions(-)
+```
+
+---
+
+## 12:40:27 세션 완료
+
+### 변경 파일
+- backend/src/agents/legal/categories.py
+- docs/retrospective/2026-05-05.md
+
+### diff 요약
+```
+ backend/src/agents/legal/categories.py | 18 ++++++++--------
+ docs/retrospective/2026-05-05.md       | 39 ++++++++++++++++++++++++++++++++++
+ 2 files changed, 48 insertions(+), 9 deletions(-)
+```
+
+---
+
+## 12:41:12 세션 완료
+
+### 변경 파일
+- backend/src/agents/legal/categories.py
+- docs/retrospective/2026-05-05.md
+
+### diff 요약
+```
+ backend/src/agents/legal/categories.py | 18 ++++++------
+ docs/retrospective/2026-05-05.md       | 54 ++++++++++++++++++++++++++++++++++
+ 2 files changed, 63 insertions(+), 9 deletions(-)
+```
+
+---