add server api handlers. Fix bug with cmd output

.env.example

@@ -17,3 +17,6 @@ NEXUS_SYNC_CLIENT_TOKENS="dev-client:dev-token"
 
 # Logging level for the server: DEBUG, INFO, WARNING, ERROR, CRITICAL.
 NEXUS_SYNC_LOG_LEVEL="INFO"
+
+# SQLAlchemy database URL. The default is a local SQLite database.
+NEXUS_SYNC_DATABASE_URL="sqlite:///nexus-sync.db"

README.md

@@ -53,6 +53,37 @@ stays local to the client config.
 - Client behavior notes: [docs/client.md](docs/client.md)
 - Server behavior notes: [docs/server.md](docs/server.md)
 
+## Server API
+
+The server uses SQLite through SQLAlchemy by default:
+
+```bash
+NEXUS_SYNC_DATABASE_URL="sqlite:///nexus-sync.db"
+```
+
+Useful server-side handlers:
+
+```text
+POST /api/v1/client/heartbeat
+GET  /api/v1/server/clients
+GET  /api/v1/server/clients/{client_id}
+POST /api/v1/server/clients/{client_id}/commands
+GET  /api/v1/server/commands/{command_id}
+```
+
+Queue command example:
+
+```json
+{
+  "name": "hostname",
+  "args": {},
+  "timeout_seconds": 30
+}
+```
+
+Clients receive queued commands on their next heartbeat and report results in a
+later heartbeat.
+
 ### To build
 
 ```

docs/api.md

@@ -138,6 +138,58 @@ Authorization: Bearer <client-token>
 Клиент обязан выполнять только те команды, которые он знает и локально
 разрешает. Неизвестные или запрещённые команды нужно возвращать как `rejected`.
 
+## Server-side API
+
+Эти ручки нужны серверной части/админке, чтобы видеть клиентов и ставить им
+команды в очередь. Клиенты напрямую используют только heartbeat.
+
+### `GET /api/v1/server/clients`
+
+Возвращает список известных клиентов с последними heartbeat-данными и
+`available_commands`.
+
+### `GET /api/v1/server/clients/{client_id}`
+
+Возвращает одного клиента или `404`, если сервер ещё не видел этот `client_id`.
+
+### `POST /api/v1/server/clients/{client_id}/commands`
+
+Создаёт pending-команду для клиента. Клиент получит её на следующем heartbeat.
+Эта ручка принимает имя команды напрямую.
+
+Request:
+
+```json
+{
+  "name": "hostname",
+  "args": {},
+  "timeout_seconds": 30
+}
+```
+
+Response:
+
+```json
+{
+  "id": "cmd_...",
+  "client_id": "macbook-pro-01",
+  "kind": "exec",
+  "name": "hostname",
+  "args": {},
+  "status": "pending",
+  "timeout_seconds": 30,
+  "attempts": 0,
+  "max_attempts": 1,
+  "created_at": "2026-05-24T13:20:30Z",
+  "delivered_at": null,
+  "finished_at": null
+}
+```
+
+### `GET /api/v1/server/commands/{command_id}`
+
+Возвращает команду и, если клиент уже отчитался, поле `result`.
+
 ## Command lifecycle
 
 Жизненный цикл команды:

src/nexus_sync/client/runtime.py

@@ -246,22 +246,25 @@ def main(argv: list[str] | None = None) -> int:
     try:
         config = load_client_config()
         result = run_once(config)
+        if result is None:
+            logger.info("heartbeat accepted; no command")
+            return 0
+
+        while result is not None:
+            logger.info(
+                "command result: %s",
+                json.dumps(
+                    result.model_dump(mode="json"),
+                    ensure_ascii=False,
+                    separators=(",", ":"),
+                ),
+            )
+            result = run_once(config, last_command_result=result)
+            logger.info("command result reported to server")
     except (ClientConfigError, HeartbeatError, ValueError) as error:
         logger.error("nexus-sync client error: %s", error)
         return 1
 
-    if result is None:
-        logger.info("heartbeat accepted; no command")
-        return 0
-
-    logger.info(
-        "command result: %s",
-        json.dumps(
-            result.model_dump(mode="json"),
-            ensure_ascii=False,
-            separators=(",", ":"),
-        ),
-    )
     return 0
 
 

src/nexus_sync/server/__init__.py

@@ -1,11 +1,13 @@
 from nexus_sync.server.app import create_app
 from nexus_sync.server.config import DEFAULT_COMMAND_POLL_SECONDS, DEFAULT_IDLE_POLL_SECONDS
+from nexus_sync.server.sqlalchemy_store import SQLAlchemyStore
 from nexus_sync.server.store import InMemoryStore, Store
 
 __all__ = [
     "DEFAULT_COMMAND_POLL_SECONDS",
     "DEFAULT_IDLE_POLL_SECONDS",
     "InMemoryStore",
+    "SQLAlchemyStore",
     "Store",
     "create_app",
 ]

src/nexus_sync/server/app.py

@@ -1,16 +1,27 @@
 from datetime import UTC, datetime
+from typing import Any
+from uuid import uuid4
 
 from fastapi import Depends, FastAPI, Header, HTTPException, Request, status
 from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse
+from pydantic import BaseModel, Field
 
-from nexus_sync.common import HeartbeatRequest, HeartbeatResponse
+from nexus_sync.common import Command, CommandKind, HeartbeatRequest, HeartbeatResponse
 from nexus_sync.server.config import (
     DEFAULT_COMMAND_POLL_SECONDS,
     DEFAULT_IDLE_POLL_SECONDS,
     load_client_tokens,
+    load_database_url,
 )
-from nexus_sync.server.store import InMemoryStore, Store
+from nexus_sync.server.sqlalchemy_store import SQLAlchemyStore
+from nexus_sync.server.store import Store
+
+
+class CommandCreateRequest(BaseModel):
+    name: str
+    args: dict[str, Any] = Field(default_factory=dict)
+    timeout_seconds: int = Field(default=30, gt=0)
 
 
 def create_app(
@@ -19,7 +30,7 @@ def create_app(
     client_tokens: dict[str, str] | None = None,
 ) -> FastAPI:
     app = FastAPI(title="nexus-sync", version="0.1.0")
-    app.state.store = store or InMemoryStore()
+    app.state.store = store or SQLAlchemyStore(load_database_url())
     app.state.client_tokens = client_tokens if client_tokens is not None else load_client_tokens()
 
     @app.exception_handler(RequestValidationError)
@@ -71,6 +82,43 @@ def create_app(
             command=command,
         )
 
+    @app.get("/api/v1/server/clients")
+    def list_clients() -> dict[str, list[dict[str, Any]]]:
+        return {
+            "clients": [client.model_dump(mode="json") for client in app.state.store.list_clients()]
+        }
+
+    @app.get("/api/v1/server/clients/{client_id}")
+    def get_client(client_id: str) -> dict[str, Any]:
+        client = app.state.store.get_client(client_id)
+        if client is None:
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="client not found")
+        return client.model_dump(mode="json")
+
+    @app.post("/api/v1/server/clients/{client_id}/commands", status_code=status.HTTP_201_CREATED)
+    def create_command(client_id: str, payload: CommandCreateRequest) -> dict[str, Any]:
+        if app.state.store.get_client(client_id) is None:
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="client not found")
+
+        return _enqueue_command(
+            store=app.state.store,
+            client_id=client_id,
+            name=payload.name,
+            args=payload.args,
+            timeout_seconds=payload.timeout_seconds,
+        )
+
+    @app.get("/api/v1/server/commands/{command_id}")
+    def get_command(command_id: str) -> dict[str, Any]:
+        command = app.state.store.get_command(command_id)
+        if command is None:
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="command not found")
+
+        body = command.model_dump(mode="json")
+        result = app.state.store.get_command_result(command_id)
+        body["result"] = result.model_dump(mode="json") if result else None
+        return body
+
     return app
 
 
@@ -81,4 +129,24 @@ def _client_id_for_token(client_tokens: dict[str, str], token: str) -> str | Non
     return None
 
 
+def _enqueue_command(
+    *,
+    store: Store,
+    client_id: str,
+    name: str,
+    args: dict[str, Any],
+    timeout_seconds: int,
+) -> dict[str, Any]:
+    now = datetime.now(UTC)
+    command = Command(
+        id=f"cmd_{uuid4().hex}",
+        kind=CommandKind.EXEC,
+        name=name,
+        args=args,
+        timeout_seconds=timeout_seconds,
+    )
+    record = store.enqueue_command(command, client_id, now)
+    return record.model_dump(mode="json")
+
+
 app = create_app()

src/nexus_sync/server/config.py

@@ -2,6 +2,11 @@ import os
 
 DEFAULT_IDLE_POLL_SECONDS = 60
 DEFAULT_COMMAND_POLL_SECONDS = 10
+DEFAULT_DATABASE_URL = "sqlite:///nexus-sync.db"
+
+
+def load_database_url() -> str:
+    return os.environ.get("NEXUS_SYNC_DATABASE_URL", DEFAULT_DATABASE_URL)
 
 
 def load_client_tokens() -> dict[str, str]:

src/nexus_sync/server/sqlalchemy_store.py

@@ -0,0 +1,205 @@
+from datetime import datetime
+
+from fastapi import HTTPException, status
+from sqlalchemy import Column, MetaData, String, Table, create_engine, select
+from sqlalchemy.engine import Engine
+
+from nexus_sync.common import (
+    ClientRecord,
+    Command,
+    CommandRecord,
+    CommandResultRecord,
+    CommandStatus,
+    HeartbeatRequest,
+)
+from nexus_sync.server.store import TERMINAL_COMMAND_STATUSES
+
+
+class SQLAlchemyStore:
+    def __init__(self, database_url: str = "sqlite:///nexus-sync.db") -> None:
+        self.engine = create_engine(database_url)
+        self.metadata = MetaData()
+        self.clients = Table(
+            "clients",
+            self.metadata,
+            Column("id", String, primary_key=True),
+            Column("json", String, nullable=False),
+        )
+        self.commands = Table(
+            "commands",
+            self.metadata,
+            Column("id", String, primary_key=True),
+            Column("client_id", String, nullable=False, index=True),
+            Column("status", String, nullable=False, index=True),
+            Column("created_at", String, nullable=False, index=True),
+            Column("json", String, nullable=False),
+        )
+        self.results = Table(
+            "command_results",
+            self.metadata,
+            Column("command_id", String, primary_key=True),
+            Column("json", String, nullable=False),
+        )
+        self.metadata.create_all(self.engine)
+
+    def list_clients(self) -> list[ClientRecord]:
+        with self.engine.begin() as connection:
+            rows = connection.execute(select(self.clients.c.json).order_by(self.clients.c.id)).all()
+        return [ClientRecord.model_validate_json(row.json) for row in rows]
+
+    def get_client(self, client_id: str) -> ClientRecord | None:
+        with self.engine.begin() as connection:
+            row = connection.execute(
+                select(self.clients.c.json).where(self.clients.c.id == client_id)
+            ).first()
+        return ClientRecord.model_validate_json(row.json) if row else None
+
+    def upsert_client_from_payload(self, payload: dict, now: datetime) -> ClientRecord:
+        return self.upsert_client(HeartbeatRequest.model_validate(payload), now)
+
+    def upsert_client(self, heartbeat: HeartbeatRequest, now: datetime) -> ClientRecord:
+        existing = self.get_client(heartbeat.client_id)
+        created_at = existing.created_at if existing else now
+        token_hash = existing.token_hash if existing else None
+        record = ClientRecord(
+            id=heartbeat.client_id,
+            hostname=heartbeat.client.hostname,
+            platform=heartbeat.client.platform,
+            version=heartbeat.client.version,
+            created_at=created_at,
+            last_seen_at=now,
+            is_active=True,
+            token_hash=token_hash,
+            available_commands=heartbeat.available_commands,
+        )
+        with self.engine.begin() as connection:
+            connection.execute(self.clients.delete().where(self.clients.c.id == record.id))
+            connection.execute(
+                self.clients.insert().values(id=record.id, json=record.model_dump_json())
+            )
+        return record
+
+    def enqueue_command(self, command: Command, client_id: str, now: datetime) -> CommandRecord:
+        record = CommandRecord(
+            id=command.id,
+            client_id=client_id,
+            kind=command.kind,
+            name=command.name,
+            args=command.args,
+            status=CommandStatus.PENDING,
+            timeout_seconds=command.timeout_seconds,
+            created_at=now,
+        )
+        self._write_command(record)
+        return record
+
+    def record_command_result_from_payload(self, payload: dict, now: datetime) -> None:
+        self.record_command_result(HeartbeatRequest.model_validate(payload), now)
+
+    def record_command_result(self, heartbeat: HeartbeatRequest, now: datetime) -> None:
+        result = heartbeat.last_command_result
+        if result is None:
+            return
+
+        command = self.get_command(result.command_id)
+        if command is None:
+            raise HTTPException(
+                status_code=status.HTTP_409_CONFLICT,
+                detail="command result references unknown command",
+            )
+        if command.client_id != heartbeat.client_id:
+            raise HTTPException(
+                status_code=status.HTTP_409_CONFLICT,
+                detail="command result references command for another client",
+            )
+        if command.status in TERMINAL_COMMAND_STATUSES:
+            raise HTTPException(
+                status_code=status.HTTP_409_CONFLICT,
+                detail="command result references terminal command",
+            )
+
+        finished_at = result.finished_at or now
+        self._write_command(
+            command.model_copy(
+                update={
+                    "status": CommandStatus(result.status.value),
+                    "finished_at": finished_at,
+                }
+            )
+        )
+        record = CommandResultRecord(
+            command_id=result.command_id,
+            client_id=heartbeat.client_id,
+            status=result.status,
+            started_at=result.started_at,
+            finished_at=finished_at,
+            return_code=result.return_code,
+            stdout=result.stdout,
+            stderr=result.stderr,
+            received_at=now,
+        )
+        with self.engine.begin() as connection:
+            connection.execute(
+                self.results.delete().where(self.results.c.command_id == record.command_id)
+            )
+            connection.execute(
+                self.results.insert().values(
+                    command_id=record.command_id,
+                    json=record.model_dump_json(),
+                )
+            )
+
+    def take_next_command(self, client_id: str, now: datetime) -> Command | None:
+        with self.engine.begin() as connection:
+            rows = connection.execute(
+                select(self.commands.c.json)
+                .where(self.commands.c.client_id == client_id)
+                .where(self.commands.c.status == CommandStatus.PENDING.value)
+                .order_by(self.commands.c.created_at)
+            ).all()
+        if not rows:
+            return None
+
+        record = CommandRecord.model_validate_json(rows[0].json)
+        delivered = record.model_copy(
+            update={
+                "status": CommandStatus.DELIVERED,
+                "attempts": record.attempts + 1,
+                "delivered_at": now,
+            }
+        )
+        self._write_command(delivered)
+        return Command(
+            id=delivered.id,
+            kind=delivered.kind,
+            name=delivered.name,
+            args=delivered.args,
+            timeout_seconds=delivered.timeout_seconds,
+        )
+
+    def get_command(self, command_id: str) -> CommandRecord | None:
+        with self.engine.begin() as connection:
+            row = connection.execute(
+                select(self.commands.c.json).where(self.commands.c.id == command_id)
+            ).first()
+        return CommandRecord.model_validate_json(row.json) if row else None
+
+    def get_command_result(self, command_id: str) -> CommandResultRecord | None:
+        with self.engine.begin() as connection:
+            row = connection.execute(
+                select(self.results.c.json).where(self.results.c.command_id == command_id)
+            ).first()
+        return CommandResultRecord.model_validate_json(row.json) if row else None
+
+    def _write_command(self, record: CommandRecord) -> None:
+        with self.engine.begin() as connection:
+            connection.execute(self.commands.delete().where(self.commands.c.id == record.id))
+            connection.execute(
+                self.commands.insert().values(
+                    id=record.id,
+                    client_id=record.client_id,
+                    status=record.status.value,
+                    created_at=record.created_at.isoformat(),
+                    json=record.model_dump_json(),
+                )
+            )

src/nexus_sync/server/store.py

@@ -15,15 +15,30 @@ from nexus_sync.common import (
 
 
 class Store(Protocol):
+    def list_clients(self) -> list[ClientRecord]:
+        pass
+
+    def get_client(self, client_id: str) -> ClientRecord | None:
+        pass
+
     def upsert_client(self, heartbeat: HeartbeatRequest, now: datetime) -> ClientRecord:
         pass
 
+    def enqueue_command(self, command: Command, client_id: str, now: datetime) -> CommandRecord:
+        pass
+
     def record_command_result(self, heartbeat: HeartbeatRequest, now: datetime) -> None:
         pass
 
     def take_next_command(self, client_id: str, now: datetime) -> Command | None:
         pass
 
+    def get_command(self, command_id: str) -> CommandRecord | None:
+        pass
+
+    def get_command_result(self, command_id: str) -> CommandResultRecord | None:
+        pass
+
 
 @dataclass
 class InMemoryStore:
@@ -31,6 +46,12 @@ class InMemoryStore:
     commands: dict[str, CommandRecord] = field(default_factory=dict)
     results: list[CommandResultRecord] = field(default_factory=list)
 
+    def list_clients(self) -> list[ClientRecord]:
+        return sorted(self.clients.values(), key=lambda client: client.id)
+
+    def get_client(self, client_id: str) -> ClientRecord | None:
+        return self.clients.get(client_id)
+
     def upsert_client(self, heartbeat: HeartbeatRequest, now: datetime) -> ClientRecord:
         existing = self.clients.get(heartbeat.client_id)
         created_at = existing.created_at if existing else now
@@ -135,6 +156,15 @@ class InMemoryStore:
             timeout_seconds=record.timeout_seconds,
         )
 
+    def get_command(self, command_id: str) -> CommandRecord | None:
+        return self.commands.get(command_id)
+
+    def get_command_result(self, command_id: str) -> CommandResultRecord | None:
+        for result in reversed(self.results):
+            if result.command_id == command_id:
+                return result
+        return None
+
 
 TERMINAL_COMMAND_STATUSES = {
     CommandStatus.SUCCEEDED,

tests/test_client_runtime.py

@@ -387,7 +387,7 @@ def test_main_logs_success_without_command(monkeypatch, caplog, tmp_path) -> Non
     assert "heartbeat accepted; no command" in caplog.text
 
 
-def test_main_logs_command_result(monkeypatch, caplog, tmp_path) -> None:
+def test_main_logs_and_reports_command_result(monkeypatch, caplog, tmp_path) -> None:
     caplog.set_level("INFO")
     monkeypatch.chdir(tmp_path)
     (tmp_path / "nexus.yml").write_text(
@@ -400,21 +400,27 @@ def test_main_logs_command_result(monkeypatch, caplog, tmp_path) -> None:
             ]
         )
     )
-    monkeypatch.setattr(
-        "nexus_sync.client.runtime.run_once",
-        lambda _config: CommandResult(
-            command_id="cmd_01JY3H8V8W8P3FXDR3S2BM7M6B",
-            status=CommandResultStatus.SUCCEEDED,
-            return_code=0,
-            stdout="host\n",
-            stderr="",
-        ),
+    command_result = CommandResult(
+        command_id="cmd_01JY3H8V8W8P3FXDR3S2BM7M6B",
+        status=CommandResultStatus.SUCCEEDED,
+        return_code=0,
+        stdout="host\n",
+        stderr="",
     )
+    reported_results = []
+
+    def fake_run_once(_config: ClientConfig, *, last_command_result=None):
+        reported_results.append(last_command_result)
+        return command_result if last_command_result is None else None
+
+    monkeypatch.setattr("nexus_sync.client.runtime.run_once", fake_run_once)
 
     exit_code = main([])
 
     assert exit_code == 0
+    assert reported_results == [None, command_result]
     assert "command result:" in caplog.text
+    assert "command result reported to server" in caplog.text
     assert '"command_id":"cmd_01JY3H8V8W8P3FXDR3S2BM7M6B"' in caplog.text
 
 

tests/test_server_api.py

@@ -0,0 +1,118 @@
+from fastapi.testclient import TestClient
+
+from nexus_sync.server import InMemoryStore, Store, create_app
+
+
+def _heartbeat_payload(client_id: str = "macbook-pro-01", result: dict | None = None) -> dict:
+    return {
+        "client_id": client_id,
+        "observed_at": "2026-05-24T13:20:30Z",
+        "client": {
+            "hostname": "macbook-pro.local",
+            "platform": "darwin",
+            "version": "0.1.0",
+        },
+        "state": {
+            "local_time": "2026-05-24T16:20:30+03:00",
+            "uptime_seconds": 1200,
+        },
+        "last_command_result": result,
+    }
+
+
+def _client(store: Store | None = None) -> TestClient:
+    app = create_app(
+        store=store or InMemoryStore(),
+        client_tokens={"macbook-pro-01": "client-token", "other-client": "other-token"},
+    )
+    return TestClient(app)
+
+
+def _send_heartbeat(client: TestClient, payload: dict | None = None):
+    return client.post(
+        "/api/v1/client/heartbeat",
+        json=payload or _heartbeat_payload(),
+        headers={"Authorization": "Bearer client-token"},
+    )
+
+
+def test_server_lists_clients_after_heartbeat() -> None:
+    store = InMemoryStore()
+    client = _client(store)
+    payload = _heartbeat_payload()
+    payload["available_commands"] = [
+        {"name": "hostname", "description": "Get hostname"},
+    ]
+    _send_heartbeat(client, payload)
+
+    response = client.get("/api/v1/server/clients")
+
+    assert response.status_code == 200
+    assert response.json()["clients"][0]["id"] == "macbook-pro-01"
+    assert response.json()["clients"][0]["available_commands"] == [
+        {"name": "hostname", "description": "Get hostname"},
+    ]
+
+
+def test_server_queues_command_for_client_and_heartbeat_delivers_it() -> None:
+    store = InMemoryStore()
+    client = _client(store)
+    _send_heartbeat(client)
+
+    created = client.post(
+        "/api/v1/server/clients/macbook-pro-01/commands",
+        json={"name": "hostname", "args": {}, "timeout_seconds": 30},
+    )
+
+    assert created.status_code == 201
+    command_id = created.json()["id"]
+    assert created.json()["client_id"] == "macbook-pro-01"
+    assert created.json()["status"] == "pending"
+
+    heartbeat = _send_heartbeat(client)
+
+    assert heartbeat.status_code == 200
+    assert heartbeat.json()["command"]["id"] == command_id
+    assert heartbeat.json()["command"]["name"] == "hostname"
+
+
+def test_server_rejects_command_for_unknown_client() -> None:
+    client = _client()
+
+    response = client.post(
+        "/api/v1/server/clients/missing-client/commands",
+        json={"name": "hostname", "args": {}, "timeout_seconds": 30},
+    )
+
+    assert response.status_code == 404
+
+
+def test_server_returns_command_with_result_after_client_reports_result() -> None:
+    store = InMemoryStore()
+    client = _client(store)
+    _send_heartbeat(client)
+    created = client.post(
+        "/api/v1/server/clients/macbook-pro-01/commands",
+        json={"name": "hostname", "args": {}, "timeout_seconds": 30},
+    )
+    command_id = created.json()["id"]
+    _send_heartbeat(client)
+
+    reported = _send_heartbeat(
+        client,
+        _heartbeat_payload(
+            result={
+                "command_id": command_id,
+                "status": "succeeded",
+                "return_code": 0,
+                "stdout": "host\n",
+                "stderr": "",
+            }
+        ),
+    )
+    fetched = client.get(f"/api/v1/server/commands/{command_id}")
+
+    assert reported.status_code == 200
+    assert fetched.status_code == 200
+    assert fetched.json()["status"] == "succeeded"
+    assert fetched.json()["result"]["stdout"] == "host\n"

tests/test_sqlalchemy_store.py

@@ -0,0 +1,64 @@
+from datetime import UTC, datetime
+
+from nexus_sync.common import Command, CommandKind, CommandStatus
+from nexus_sync.server.sqlalchemy_store import SQLAlchemyStore
+
+
+def _heartbeat_payload(client_id: str = "macbook-pro-01", result: dict | None = None) -> dict:
+    return {
+        "client_id": client_id,
+        "observed_at": "2026-05-24T13:20:30Z",
+        "client": {
+            "hostname": "macbook-pro.local",
+            "platform": "darwin",
+            "version": "0.1.0",
+        },
+        "state": {
+            "local_time": "2026-05-24T16:20:30+03:00",
+            "uptime_seconds": 1200,
+        },
+        "available_commands": [
+            {"name": "hostname", "description": "Get hostname"},
+        ],
+        "last_command_result": result,
+    }
+
+
+def test_sqlalchemy_store_persists_clients_commands_and_results(tmp_path) -> None:
+    db_url = f"sqlite:///{tmp_path / 'nexus-sync.db'}"
+    store = SQLAlchemyStore(db_url)
+    now = datetime(2026, 5, 24, 13, 20, tzinfo=UTC)
+
+    store.upsert_client_from_payload(_heartbeat_payload(), now)
+    command = Command(
+        id="cmd_01JY3H8V8W8P3FXDR3S2BM7M6B",
+        kind=CommandKind.EXEC,
+        name="hostname",
+        args={},
+        timeout_seconds=30,
+    )
+    store.enqueue_command(command, "macbook-pro-01", now)
+
+    reloaded = SQLAlchemyStore(db_url)
+    assert reloaded.get_client("macbook-pro-01") is not None
+    assert reloaded.get_client("macbook-pro-01").available_commands[0].name == "hostname"
+
+    delivered = reloaded.take_next_command("macbook-pro-01", now)
+    assert delivered is not None
+    assert delivered.id == command.id
+    assert reloaded.get_command(command.id).status == CommandStatus.DELIVERED
+
+    result_payload = _heartbeat_payload(
+        result={
+            "command_id": command.id,
+            "status": "succeeded",
+            "return_code": 0,
+            "stdout": "host\n",
+            "stderr": "",
+        }
+    )
+    reloaded.record_command_result_from_payload(result_payload, now)
+
+    final = SQLAlchemyStore(db_url)
+    assert final.get_command(command.id).status == CommandStatus.SUCCEEDED
+    assert final.get_command_result(command.id).stdout == "host\n"