diff --git a/scripts/backfill_material_axis.py b/scripts/backfill_material_axis.py
new file mode 100644
index 0000000..a27fd80
--- /dev/null
+++ b/scripts/backfill_material_axis.py
@@ -0,0 +1,219 @@
+"""안전 자료실 A-3 백필 — 기존 코퍼스에 material_type/jurisdiction/published_date/license 소급.
+
+plan: safety-library-1 A-3 (PKM plans/2026-06-12-safety-library-plan.html)
+선례: backfill_category.py (one-off 멱등 스크립트 — migration 아님, 152 단일 트랜잭션 제약 회피)
+
+술어 (2026-06-13 prod 실측 교정 — R2 blocker 반영):
+  1. extract_meta.source_id JOIN news_sources  → 레지스트리 material_type/country 전파
+     (KOSHA 사례 본문·CSB 페이지·HSE·MOEL·JPVT·arXiv·NB·TWI·API 공지 전부 커버.
+      paper 는 jurisdiction NULL 강제 — plan 0-1. KOSHA 본문의 kosha.kind='case' 가정은
+      실측 부정됨: kind 는 첨부/GUIDE 에만 존재 → source_id JOIN 이 정본 술어)
+  2. kosha.kind='case_attachment'              → incident/KR
+  3. kosha.kind='guide'                        → guide/KR (+ ofancYmd 'YYYY-MM-DD' 실측)
+  4. csb.kind='report_pdf'                     → incident/US (source_id 없음 — JOIN 비대상)
+  5. source_channel='law_monitor'              → law/KR (243건. legal_meta 생략 — MST 미보존,
+     버전 체인은 B-1 가동 시점부터. published_date = title 의 '(YYYYMMDD)' 공포일 추출 —
+     extract_meta 빈값 실측, R3-m1 의 'NULL 허용' 보다 1줄 정규식이 저렴해 채움)
+  6. file_path LIKE '%KGS_Code%'               → law/KR (frontmatter 키 = 'code' 실측 117/118,
+     'kgs_code' 0건. 경로 술어가 더 단순·전수. license 는 B-4 소관 — 미주입)
+
+불변식:
+  - 전 UPDATE 에 material_type IS NULL 가드 (멱등 — 재실행 안전, A-2 신규 유입분 무접촉)
+  - material_type + jurisdiction 동일 statement (law CHECK chk_documents_law_jurisdiction 충족)
+  - published_date / license 는 각자 필드 부재 가드 (이미 값 있으면 무접촉)
+  - 업로드 Industrial_Safety 문서 = 대상 아님 (LLM 제안+승인 경로만 — 자동 전이 금지)
+  - 코퍼스(청크/임베딩) 무접촉 — 검색 지표 무변동이 정상
+
+실행:
+  docker compose exec -T fastapi python /app/scripts/backfill_material_axis.py --dry-run
+  docker compose exec -T fastapi python /app/scripts/backfill_material_axis.py --apply
+"""
+
+import argparse
+import asyncio
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "app"))
+
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import create_async_engine
+
+# ─── 술어별 (라벨, 카운트 SQL, 적용 SQL) ───────────────────────────────────────
+
+_KOSHA_LICENSE = ("kogl", "false", "한국산업안전보건공단(KOSHA)")
+_CSB_LICENSE = ("public_domain", "true", "U.S. Chemical Safety Board")
+_LAW_LICENSE = ("public_domain", "true", "국가법령정보센터")
+
+
+def _license_obj(scheme: str, redistribute: str, attribution: str) -> str:
+    return (
+        f"jsonb_build_object('license', jsonb_build_object("
+        f"'scheme', '{scheme}', 'redistribute', {redistribute}::boolean, "
+        f"'attribution', '{attribution}'))"
+    )
+
+
+STEPS: list[tuple[str, str]] = [
+    # 1) 레지스트리 전파 (source_id JOIN)
+    ("1. src_join material/jurisdiction", """
+        UPDATE documents d SET
+            material_type = ns.material_type,
+            jurisdiction = CASE WHEN ns.material_type = 'paper' THEN NULL ELSE ns.country END
+        FROM news_sources ns
+        WHERE d.material_type IS NULL AND d.deleted_at IS NULL
+          AND d.extract_meta->>'source_id' ~ '^[0-9]+$'
+          AND ns.id = (d.extract_meta->>'source_id')::int
+          AND ns.material_type IS NOT NULL
+    """),
+    # 2) KOSHA 첨부
+    ("2. kosha 첨부 incident/KR", """
+        UPDATE documents SET material_type = 'incident', jurisdiction = 'KR'
+        WHERE material_type IS NULL AND deleted_at IS NULL
+          AND extract_meta#>>'{kosha,kind}' = 'case_attachment'
+    """),
+    # 3) KOSHA GUIDE
+    ("3. kosha GUIDE guide/KR", """
+        UPDATE documents SET material_type = 'guide', jurisdiction = 'KR'
+        WHERE material_type IS NULL AND deleted_at IS NULL
+          AND extract_meta#>>'{kosha,kind}' = 'guide'
+    """),
+    # 4) CSB 보고서 PDF
+    ("4. csb PDF incident/US", """
+        UPDATE documents SET material_type = 'incident', jurisdiction = 'US'
+        WHERE material_type IS NULL AND deleted_at IS NULL
+          AND extract_meta#>>'{csb,kind}' = 'report_pdf'
+    """),
+    # 5) 레거시 law_monitor
+    ("5. law_monitor law/KR", """
+        UPDATE documents SET material_type = 'law', jurisdiction = 'KR'
+        WHERE material_type IS NULL AND deleted_at IS NULL
+          AND source_channel = 'law_monitor'
+    """),
+    # 6) KGS Code watch 폴더
+    ("6. KGS law/KR", """
+        UPDATE documents SET material_type = 'law', jurisdiction = 'KR'
+        WHERE material_type IS NULL AND deleted_at IS NULL
+          AND file_path LIKE '%KGS_Code%'
+    """),
+    # 7) published_date — crawl/news 공통 (extract_meta.published_at ISO)
+    ("7. published_date (published_at)", """
+        UPDATE documents SET published_date = (extract_meta->>'published_at')::date
+        WHERE published_date IS NULL AND deleted_at IS NULL
+          AND extract_meta->>'published_at' ~ '^\\d{4}-\\d{2}-\\d{2}'
+    """),
+    # 8) published_date — KOSHA GUIDE 공표일자 ('YYYY-MM-DD' 실측)
+    ("8. published_date (GUIDE ofancYmd)", """
+        UPDATE documents SET published_date = (extract_meta#>>'{kosha,ofancYmd}')::date
+        WHERE published_date IS NULL AND deleted_at IS NULL
+          AND extract_meta#>>'{kosha,ofancYmd}' ~ '^\\d{4}-\\d{2}-\\d{2}$'
+    """),
+    # 9) published_date — 레거시 law title 공포일 '(YYYYMMDD)'
+    ("9. published_date (law title 공포일)", """
+        UPDATE documents
+        SET published_date = to_date(substring(title from '\\((20\\d{2}(?:0[1-9]|1[0-2])(?:0[1-9]|[12]\\d|3[01]))\\)'), 'YYYYMMDD')
+        WHERE published_date IS NULL AND deleted_at IS NULL
+          AND source_channel = 'law_monitor'
+          AND title ~ '\\((20\\d{2}(?:0[1-9]|1[0-2])(?:0[1-9]|[12]\\d|3[01]))\\)'
+    """),
+    # 10) license — 레지스트리 전파 (scheme 있는 소스만)
+    ("10. license (src_join)", """
+        UPDATE documents d SET
+            extract_meta = COALESCE(d.extract_meta, '{}'::jsonb)
+                || jsonb_build_object('license', jsonb_build_object(
+                       'scheme', ns.license_scheme,
+                       'redistribute', COALESCE(ns.license_redistribute, false),
+                       'attribution', ns.name))
+        FROM news_sources ns
+        WHERE d.deleted_at IS NULL AND NOT (COALESCE(d.extract_meta, '{}'::jsonb) ? 'license')
+          AND d.extract_meta->>'source_id' ~ '^[0-9]+$'
+          AND ns.id = (d.extract_meta->>'source_id')::int
+          AND ns.license_scheme IS NOT NULL
+    """),
+    # 11) license — KOSHA 첨부/GUIDE (source_id 없음)
+    ("11. license (kosha kinds)", f"""
+        UPDATE documents SET
+            extract_meta = COALESCE(extract_meta, '{{}}'::jsonb) || {_license_obj(*_KOSHA_LICENSE)}
+        WHERE deleted_at IS NULL AND NOT (COALESCE(extract_meta, '{{}}'::jsonb) ? 'license')
+          AND extract_meta#>>'{{kosha,kind}}' IN ('case_attachment', 'guide')
+    """),
+    # 12) license — CSB PDF
+    ("12. license (csb PDF)", f"""
+        UPDATE documents SET
+            extract_meta = COALESCE(extract_meta, '{{}}'::jsonb) || {_license_obj(*_CSB_LICENSE)}
+        WHERE deleted_at IS NULL AND NOT (COALESCE(extract_meta, '{{}}'::jsonb) ? 'license')
+          AND extract_meta#>>'{{csb,kind}}' = 'report_pdf'
+    """),
+    # 13) license — 레거시 법령 (저작권법 제7조 비보호)
+    ("13. license (law_monitor)", f"""
+        UPDATE documents SET
+            extract_meta = COALESCE(extract_meta, '{{}}'::jsonb) || {_license_obj(*_LAW_LICENSE)}
+        WHERE deleted_at IS NULL AND NOT (COALESCE(extract_meta, '{{}}'::jsonb) ? 'license')
+          AND source_channel = 'law_monitor'
+    """),
+]
+
+VERIFY_SQL = [
+    ("축 전수표 (material_type x jurisdiction)", """
+        SELECT material_type, jurisdiction, count(*) AS docs,
+               count(published_date) AS with_date,
+               count(*) FILTER (WHERE extract_meta ? 'license') AS with_license
+        FROM documents WHERE material_type IS NOT NULL AND deleted_at IS NULL
+        GROUP BY 1, 2 ORDER BY 1, 2
+    """),
+    ("law & jurisdiction NULL (0 이어야 함 — hard)", """
+        SELECT count(*) FROM documents
+        WHERE material_type = 'law' AND jurisdiction IS NULL AND deleted_at IS NULL
+    """),
+    ("잔여 미분류 안전 후보 (kosha/csb 메타 보유인데 NULL — 0 이어야 함)", """
+        SELECT count(*) FROM documents
+        WHERE material_type IS NULL AND deleted_at IS NULL
+          AND (extract_meta ? 'kosha' OR extract_meta ? 'csb')
+    """),
+]
+
+
+async def main() -> None:
+    parser = argparse.ArgumentParser()
+    mode = parser.add_mutually_exclusive_group(required=True)
+    mode.add_argument("--dry-run", action="store_true",
+                      help="전 UPDATE 를 트랜잭션 안에서 실행해 정확한 rowcount + 검증표를 보여주고 ROLLBACK (변경 0)")
+    mode.add_argument("--apply", action="store_true", help="백필 실행 (단일 트랜잭션 커밋)")
+    args = parser.parse_args()
+
+    db_url = os.getenv(
+        "DATABASE_URL", "postgresql+asyncpg://pkm:pkm@localhost:5432/pkm"
+    )
+    engine = create_async_engine(db_url)
+    tag = "apply" if args.apply else "dry-run"
+
+    async with engine.connect() as conn:
+        trans = await conn.begin()
+        try:
+            for label, sql in STEPS:
+                result = await conn.execute(text(sql))
+                print(f"[{tag}] {label}: {result.rowcount}행")
+
+            print("\n─── 검증 (트랜잭션 내 미리보기) ───")
+            for label, sql in VERIFY_SQL:
+                result = await conn.execute(text(sql))
+                rows = result.fetchall()
+                print(f"\n{label}:")
+                for row in rows:
+                    print("  ", tuple(row))
+
+            if args.apply:
+                await trans.commit()
+                print("\n[apply] 커밋 완료")
+            else:
+                await trans.rollback()
+                print("\n[dry-run] 전체 롤백 — 변경 0")
+        except Exception:
+            await trans.rollback()
+            raise
+
+    await engine.dispose()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())