diff --git a/docs/development/OpenNexus生产验收Runner.md b/docs/development/OpenNexus生产验收Runner.md
index a2f3d59..837ce62 100644
--- a/docs/development/OpenNexus生产验收Runner.md
+++ b/docs/development/OpenNexus生产验收Runner.md
@@ -24,4 +24,4 @@ python scripts/phase3-production-acceptance.py `
 
 报告目录包含 `summary.json`、`case-manifest.json`、`junit.xml`、`cases/<ID>.json` 和脱敏的 `logs/<ID>.log`。摘要记录 commit、各锁文件 SHA-256、配置摘要与已提供安装产物摘要。日志将仓库、数据根、报告根、用户主目录和配置声明的秘密值替换为占位符，并限制为 10 MiB。报告目录必须为空，避免单例复跑覆盖原始证据。
 
-当前 runner 与失败闭合行为已实现，A-02/A-03 Sidecar、B-01/B-02 凭据、D-01 扩展包以及 S-01/S-02/S-03/S-08 Sync 客户端 driver 已登记；其余 21 个生产验收 ID 尚未登记，运行时会生成 `NOT_IMPLEMENTED` 证据并退出 1。这用于阻止误报，不是这些用例的验收通过。
+当前 runner 与失败闭合行为已实现，A-02/A-03 Sidecar、B-01/B-02 凭据、D-01 扩展包、S-01/S-02/S-03/S-08 Sync 客户端以及 S-04 Sync 服务 driver 已登记；其余 20 个生产验收 ID 尚未登记，运行时会生成 `NOT_IMPLEMENTED` 证据并退出 1。这用于阻止误报，不是这些用例的验收通过。
diff --git a/scripts/acceptance_cases/s04_sync_service.py b/scripts/acceptance_cases/s04_sync_service.py
new file mode 100644
index 0000000..f232f48
--- /dev/null
+++ b/scripts/acceptance_cases/s04_sync_service.py
@@ -0,0 +1,384 @@
+"""S-04 real PostgreSQL, MinIO, and two-worker transaction acceptance."""
+
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import os
+import secrets
+import socket
+import subprocess
+import sys
+import time
+import uuid
+from concurrent.futures import ThreadPoolExecutor
+from pathlib import Path
+from urllib.error import HTTPError, URLError
+from urllib.request import Request, urlopen
+
+ROOT = Path(__file__).resolve().parents[2]
+SERVICE = ROOT / "server sync"
+MINIO_SHA256 = "af709e6ba68488404e85acdd22a3030d0f5e56a108d4b27d744f18ceb50861b4"
+
+
+def sha256(path: Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as source:
+        for chunk in iter(lambda: source.read(1024 * 1024), b""):
+            digest.update(chunk)
+    return digest.hexdigest()
+
+
+def free_port() -> int:
+    with socket.socket() as listener:
+        listener.bind(("127.0.0.1", 0))
+        return listener.getsockname()[1]
+
+
+def call(method: str, url: str, *, headers=None, body=None):
+    request_headers = dict(headers or {})
+    payload = body
+    if isinstance(body, (dict, list)):
+        payload = json.dumps(body, separators=(",", ":")).encode()
+        request_headers["Content-Type"] = "application/json"
+    request = Request(url, data=payload, headers=request_headers, method=method)
+    try:
+        response = urlopen(request, timeout=30)
+    except HTTPError as error:
+        response = error
+    data = response.read()
+    media_type = response.headers.get("Content-Type", "")
+    value = json.loads(data) if data and "json" in media_type else data
+    return response.status, value, {key.lower(): item for key, item in response.headers.items()}
+
+
+def wait_http(url: str, *, expected=200, timeout=30) -> None:
+    until = time.monotonic() + timeout
+    while time.monotonic() < until:
+        try:
+            if call("GET", url)[0] == expected:
+                return
+        except (OSError, URLError):
+            pass
+        time.sleep(0.1)
+    raise RuntimeError("SERVICE_START_TIMEOUT")
+
+
+def stop_tree(process: subprocess.Popen | None) -> None:
+    if process is None or process.poll() is not None:
+        return
+    if os.name == "nt":
+        subprocess.run(
+            ["taskkill", "/PID", str(process.pid), "/T", "/F"],
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+            check=False,
+        )
+    else:
+        process.terminate()
+    try:
+        process.wait(timeout=10)
+    except subprocess.TimeoutExpired:
+        process.kill()
+        process.wait(timeout=10)
+
+
+def result(case_id: str, status: str, reason: str, facts: dict) -> dict:
+    passed = status == "PASSED"
+    assertions = [
+        ("the production entry uses real PostgreSQL and MinIO", facts.get("dependencies") is True),
+        ("both configured Uvicorn workers serve requests", facts.get("worker_count") == 2),
+        ("one of 100 same-base commits succeeds and the other 99 conflict", facts.get("race") == {"ok": 1, "conflict": 99}),
+        ("100 same-payload idempotent retries return the original revision", facts.get("idempotent_retries") == 100),
+        ("reusing the idempotency key with a different payload is rejected", facts.get("idempotency_reused") is True),
+        ("a frozen pagination boundary has no gaps or duplicates while a later commit is added", facts.get("pagination") is True),
+        ("the object is readable before its first revision becomes visible", facts.get("object_before_revision") is True),
+    ]
+    evidence = "real PostgreSQL 17, MinIO S3, two Uvicorn workers, and black-box HTTP"
+    return {
+        "schema": 1,
+        "case_id": case_id,
+        "status": status,
+        "reason": reason,
+        "assertions": [
+            {"name": name, "status": "PASSED" if passed and actual else "FAILED", "evidence": evidence}
+            for name, actual in assertions
+        ],
+        "metrics": {
+            "successful_commits": facts.get("race", {}).get("ok", 0),
+            "conflict_responses": facts.get("race", {}).get("conflict", 0),
+            "worker_count": facts.get("worker_count", 0),
+        },
+        "files": [
+            {"path": relative, "sha256": sha256(ROOT / relative)}
+            for relative in (
+                "server sync/sync_server/app.py",
+                "server sync/sync_server/database.py",
+                "server sync/sync_server/storage.py",
+                "server sync/sync_server/__main__.py",
+                "server sync/compose.yaml",
+                "server sync/uv.lock",
+            )
+        ],
+        "revisions": [
+            {"scope": "runtime", "postgres": facts.get("postgres_version"), "minio": facts.get("minio_version")},
+            {"scope": "same-base race", "attempts": 100, **facts.get("race", {})},
+            {"scope": "fixed-boundary pagination", "boundary": facts.get("boundary", 0), "late_sequence": facts.get("late_sequence", 0)},
+        ],
+    }
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--config", required=True)
+    parser.add_argument("--output", required=True)
+    args = parser.parse_args()
+    output = Path(args.output)
+    output.parent.mkdir(parents=True, exist_ok=True)
+    case_id = os.environ.get("OPENNEXUS_ACCEPTANCE_CASE_ID", "")
+    facts: dict = {}
+    reason = ""
+    status = "FAILED"
+    postgres_started = False
+    minio = sync = None
+    handles = []
+    try:
+        config = json.loads(Path(args.config).read_text(encoding="utf-8"))
+        initdb = Path(config["artifacts"]["postgres_initdb"]).resolve()
+        pg_bin = initdb.parent
+        pg_ctl = pg_bin / ("pg_ctl.exe" if os.name == "nt" else "pg_ctl")
+        createdb = pg_bin / ("createdb.exe" if os.name == "nt" else "createdb")
+        postgres = pg_bin / ("postgres.exe" if os.name == "nt" else "postgres")
+        minio_server = Path(config["artifacts"]["minio_server"]).resolve()
+        server_python = SERVICE / (".venv/Scripts/python.exe" if os.name == "nt" else ".venv/bin/python")
+        if not all(path.is_file() for path in (initdb, pg_ctl, createdb, postgres, minio_server, server_python)):
+            raise RuntimeError("PRODUCTION_RUNTIME_MISSING")
+        postgres_version = subprocess.check_output(
+            [str(postgres), "--version"], text=True, timeout=10
+        ).strip()
+        minio_version = subprocess.check_output(
+            [str(minio_server), "--version"], text=True, timeout=10
+        ).splitlines()[0]
+        if " 17." not in postgres_version or "RELEASE.2025-09-07T16-13-09Z" not in minio_version:
+            raise RuntimeError("PRODUCTION_RUNTIME_VERSION_MISMATCH")
+        if sha256(minio_server) != MINIO_SHA256:
+            raise RuntimeError("MINIO_ARTIFACT_INTEGRITY")
+        facts.update({"postgres_version": postgres_version, "minio_version": minio_version})
+
+        data_root = Path(os.environ["OPENNEXUS_ACCEPTANCE_DATA_ROOT"])
+        stack = data_root / "s04-production-stack"
+        stack.mkdir()
+        postgres_data = stack / "postgres"
+        minio_data = stack / "objects"
+        staging = stack / "staging"
+        minio_data.mkdir()
+        staging.mkdir()
+        pg_port, minio_port, console_port, sync_port = (free_port() for _ in range(4))
+
+        pg_log = (stack / "postgres.log").open("wb")
+        minio_log = (stack / "minio.log").open("wb")
+        sync_log = (stack / "sync.log").open("wb")
+        handles.extend([pg_log, minio_log, sync_log])
+        subprocess.run(
+            [str(initdb), "-D", str(postgres_data), "-U", "postgres", "-A", "trust", "--no-locale", "-E", "UTF8"],
+            stdout=pg_log,
+            stderr=subprocess.STDOUT,
+            check=True,
+            timeout=120,
+        )
+        subprocess.run(
+            [str(pg_ctl), "-D", str(postgres_data), "-l", str(stack / "postgres-server.log"), "-o", f"-p {pg_port} -h 127.0.0.1", "-w", "start"],
+            stdout=pg_log,
+            stderr=subprocess.STDOUT,
+            check=True,
+            timeout=60,
+        )
+        postgres_started = True
+        subprocess.run(
+            [str(createdb), "-h", "127.0.0.1", "-p", str(pg_port), "-U", "postgres", "opennexus"],
+            stdout=pg_log,
+            stderr=subprocess.STDOUT,
+            check=True,
+            timeout=30,
+        )
+
+        username = "s04-" + secrets.token_hex(8)
+        password = secrets.token_urlsafe(32)
+        minio_user = "s04" + secrets.token_hex(8)
+        minio_password = secrets.token_urlsafe(32)
+        database_url = f"postgresql+psycopg://postgres@127.0.0.1:{pg_port}/opennexus"
+        minio_env = os.environ.copy()
+        minio_env.update({"MINIO_ROOT_USER": minio_user, "MINIO_ROOT_PASSWORD": minio_password})
+        minio = subprocess.Popen(
+            [str(minio_server), "server", str(minio_data), "--address", f"127.0.0.1:{minio_port}", "--console-address", f"127.0.0.1:{console_port}"],
+            stdout=minio_log,
+            stderr=subprocess.STDOUT,
+            env=minio_env,
+        )
+        wait_http(f"http://127.0.0.1:{minio_port}/minio/health/ready")
+
+        service_env = os.environ.copy()
+        service_env.update(
+            {
+                "SYNC_DATABASE_URL": database_url,
+                "SYNC_S3_ENDPOINT": f"http://127.0.0.1:{minio_port}",
+                "SYNC_S3_BUCKET": "opennexus-s04",
+                "SYNC_STAGING_DIR": str(staging),
+                "SYNC_HOST": "127.0.0.1",
+                "SYNC_PORT": str(sync_port),
+                "AWS_ACCESS_KEY_ID": minio_user,
+                "AWS_SECRET_ACCESS_KEY": minio_password,
+                "AWS_DEFAULT_REGION": "us-east-1",
+                "S04_USERNAME": username,
+                "S04_PASSWORD": password,
+            }
+        )
+        subprocess.run(
+            [
+                str(server_python),
+                "-c",
+                "import os,boto3; from sync_server.database import Database; d=Database(os.environ['SYNC_DATABASE_URL']); d.migrate(); d.add_user(os.environ['S04_USERNAME'],os.environ['S04_PASSWORD']); boto3.client('s3',endpoint_url=os.environ['SYNC_S3_ENDPOINT']).create_bucket(Bucket=os.environ['SYNC_S3_BUCKET'])",
+            ],
+            cwd=SERVICE,
+            env=service_env,
+            stdout=sync_log,
+            stderr=subprocess.STDOUT,
+            check=True,
+            timeout=60,
+        )
+        sync = subprocess.Popen(
+            [str(server_python), "-m", "sync_server", "serve", "--workers", "2"],
+            cwd=SERVICE,
+            env=service_env,
+            stdout=sync_log,
+            stderr=subprocess.STDOUT,
+        )
+        origin = f"http://127.0.0.1:{sync_port}"
+        wait_http(origin + "/ready", timeout=60)
+        facts["dependencies"] = True
+
+        code, session, _ = call(
+            "POST",
+            origin + "/sync/v1/auth/sessions",
+            body={"username": username, "password": password, "device_name": "S-04 acceptance"},
+        )
+        assert code == 200
+        auth = {"Authorization": "Bearer " + session["access_token"]}
+        code, vault, _ = call("POST", origin + "/sync/v1/vaults", headers=auth, body={"name": "S-04 isolated"})
+        assert code == 200
+        base = origin + "/sync/v1/vaults/" + vault["vault_id"]
+
+        content = b"S-04 real object"
+        content_hash = hashlib.sha256(content).hexdigest()
+        missing = {
+            "operation_id": uuid.uuid4().hex,
+            "file_id": uuid.uuid4().hex,
+            "base_revision": 0,
+            "path": "missing.md",
+            "operation": "put",
+            "content_hash": content_hash,
+            "size": len(content),
+        }
+        assert call("POST", base + "/revisions", headers=auth, body=missing)[1]["error"]["code"] == "OBJECT_NOT_READY"
+        assert call("GET", base + "/changes", headers=auth)[1]["boundary"] == 0
+        upload = call("POST", base + "/uploads", headers=auth, body={"content_hash": content_hash, "size": len(content)})[1]
+        upload_path = base + "/uploads/" + upload["upload_id"]
+        assert call("PUT", upload_path + "?offset=0", headers=auth, body=content)[0] == 200
+        assert call("POST", upload_path + "/complete", headers=auth)[0] == 200
+        assert call("GET", base + "/objects/" + content_hash, headers=auth)[1] == content
+        facts["object_before_revision"] = call("GET", base + "/changes", headers=auth)[1]["boundary"] == 0
+
+        file_id = uuid.uuid4().hex
+        race_bodies = [
+            {
+                "operation_id": uuid.uuid4().hex,
+                "file_id": file_id,
+                "base_revision": 0,
+                "path": f"race/{index:03}.md",
+                "operation": "put",
+                "content_hash": content_hash,
+                "size": len(content),
+            }
+            for index in range(100)
+        ]
+        with ThreadPoolExecutor(max_workers=100) as pool:
+            race_results = list(pool.map(lambda body: call("POST", base + "/revisions", headers=auth, body=body), race_bodies))
+        codes = [item[0] for item in race_results]
+        facts["race"] = {"ok": codes.count(200), "conflict": codes.count(409)}
+        assert facts["race"] == {"ok": 1, "conflict": 99}
+        winner_index = codes.index(200)
+        winner_body = race_bodies[winner_index]
+        winner = race_results[winner_index][1]
+        with ThreadPoolExecutor(max_workers=50) as pool:
+            retries = list(pool.map(lambda _: call("POST", base + "/revisions", headers=auth, body=winner_body), range(100)))
+        facts["idempotent_retries"] = sum(item[0] == 200 and item[1] == winner for item in retries)
+        changed = {**winner_body, "path": "different.md"}
+        reused = call("POST", base + "/revisions", headers=auth, body=changed)
+        facts["idempotency_reused"] = reused[0] == 409 and reused[1]["error"]["code"] == "IDEMPOTENCY_REUSED"
+
+        for index in range(99):
+            body = {
+                "operation_id": uuid.uuid4().hex,
+                "file_id": uuid.uuid4().hex,
+                "base_revision": 0,
+                "path": f"bulk/{index:03}.md",
+                "operation": "put",
+                "content_hash": content_hash,
+                "size": len(content),
+            }
+            assert call("POST", base + "/revisions", headers=auth, body=body)[0] == 200
+        first = call("GET", base + "/changes?cursor=0&limit=7", headers=auth)[1]
+        boundary = first["boundary"]
+        late = {
+            "operation_id": uuid.uuid4().hex,
+            "file_id": uuid.uuid4().hex,
+            "base_revision": 0,
+            "path": "late.md",
+            "operation": "put",
+            "content_hash": content_hash,
+            "size": len(content),
+        }
+        late_sequence = call("POST", base + "/revisions", headers=auth, body=late)[1]["sequence"]
+        items = list(first["items"])
+        cursor = items[-1]["sequence"]
+        while cursor < boundary:
+            page = call("GET", f"{base}/changes?cursor={cursor}&limit=7&boundary={boundary}", headers=auth)[1]
+            items.extend(page["items"])
+            cursor = items[-1]["sequence"]
+        sequences = [item["sequence"] for item in items]
+        facts["boundary"] = boundary
+        facts["late_sequence"] = late_sequence
+        facts["pagination"] = sequences == list(range(1, boundary + 1)) and late_sequence == boundary + 1
+
+        def health_worker(_):
+            return call("GET", origin + "/health", headers={"Connection": "close"})[2].get("x-opennexus-worker")
+
+        with ThreadPoolExecutor(max_workers=40) as pool:
+            worker_ids = {value for value in pool.map(health_worker, range(200)) if value}
+        facts["worker_count"] = len(worker_ids)
+        assert facts["worker_count"] == 2
+        assert sync.poll() is None and minio.poll() is None
+        status = "PASSED"
+    except BaseException as error:
+        reason = "S04_ORACLE_FAILED:" + type(error).__name__
+    finally:
+        stop_tree(sync)
+        stop_tree(minio)
+        if postgres_started:
+            subprocess.run(
+                [str(pg_ctl), "-D", str(postgres_data), "-m", "fast", "-w", "stop"],
+                stdout=subprocess.DEVNULL,
+                stderr=subprocess.DEVNULL,
+                check=False,
+                timeout=30,
+            )
+        for handle in handles:
+            handle.close()
+    payload = result(case_id, status if case_id == "S-04" else "FAILED", reason or ("" if case_id == "S-04" else "CASE_ID_MISMATCH"), facts)
+    output.write_text(json.dumps(payload, ensure_ascii=False, indent=2) + "\n", encoding="utf-8")
+    return 0 if payload["status"] == "PASSED" else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/scripts/phase3_acceptance.py b/scripts/phase3_acceptance.py
index 8c98bc0..c06b32a 100644
--- a/scripts/phase3_acceptance.py
+++ b/scripts/phase3_acceptance.py
@@ -77,6 +77,12 @@ CASE_DRIVERS: dict[str, dict[str, Any]] = {
         "timeout_seconds": 900,
         "required_metrics": (),
     },
+    "S-04": {
+        "driver": "scripts/acceptance_cases/s04_sync_service.py",
+        "timeout_seconds": 900,
+        "required_metrics": ("successful_commits", "conflict_responses", "worker_count"),
+        "required_artifacts": ("postgres_initdb", "minio_server"),
+    },
 }
 ENV_NAME = re.compile(r"[A-Z][A-Z0-9_]{2,127}")
 RUN_ID = re.compile(r"[A-Za-z0-9][A-Za-z0-9._-]{2,63}")
diff --git a/server sync/sync_server/__main__.py b/server sync/sync_server/__main__.py
index 544ddae..748d44c 100644
--- a/server sync/sync_server/__main__.py	
+++ b/server sync/sync_server/__main__.py	
@@ -33,8 +33,17 @@ def main():
         db.add_user(args.username or input("用户名: "), getpass.getpass("密码（至少12字符）: "))
     elif args.command == "serve":
         import uvicorn
+        host = os.environ.get("SYNC_HOST", "0.0.0.0")
+        if host not in {"0.0.0.0", "127.0.0.1", "::1"}:
+            raise SystemExit("SYNC_HOST 仅允许通配或本机回环地址")
+        try:
+            port = int(os.environ.get("SYNC_PORT", "8080"))
+        except ValueError as error:
+            raise SystemExit("SYNC_PORT 必须为有效端口") from error
+        if not 1 <= port <= 65535:
+            raise SystemExit("SYNC_PORT 必须为有效端口")
         uvicorn.run("sync_server.__main__:application", factory=True, workers=args.workers,
-                    host="0.0.0.0", port=8080, access_log=False)
+                    host=host, port=port, access_log=False)
     elif args.command == "cleanup-uploads":
         from .maintenance import cleanup_expired_uploads
         print(cleanup_expired_uploads(db, Path(os.environ["SYNC_STAGING_DIR"])))
diff --git a/server sync/sync_server/app.py b/server sync/sync_server/app.py
index df4e17b..85ecf52 100644
--- a/server sync/sync_server/app.py	
+++ b/server sync/sync_server/app.py	
@@ -11,7 +11,7 @@ from contextlib import asynccontextmanager
 import logging
 from pathlib import Path
 
-from fastapi import FastAPI, Header, Query, Request
+from fastapi import FastAPI, Header, Query, Request, Response
 from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse, FileResponse
 from starlette.background import BackgroundTask
@@ -59,6 +59,7 @@ def create_app(db: Database, objects, staging: Path, *, quota=1024**3, clock=tim
 
     app = FastAPI(title="OpenNexus Sync", version="1.0.0", lifespan=lifespan)
     app.state.database = db
+    worker_id = secrets.token_hex(8)
 
     @app.exception_handler(SyncError)
     async def error(_request, exc):
@@ -95,7 +96,10 @@ def create_app(db: Database, objects, staging: Path, *, quota=1024**3, clock=tim
         return {"access_token": access, "refresh_token": refresh, "expires_in": 900, "device_id": device_id}
 
     @app.get("/health")
-    def health():
+    def health(response: Response):
+        # An ephemeral identifier lets deployment probes prove that both
+        # configured workers receive traffic without exposing host identity.
+        response.headers["X-OpenNexus-Worker"] = worker_id
         return {"status": "ok"}
 
     def readiness_probe():