diff --git a/src/agent_term/matrix_cli.py b/src/agent_term/matrix_cli.py
index 56a2852..e821276 100644
--- a/src/agent_term/matrix_cli.py
+++ b/src/agent_term/matrix_cli.py
@@ -12,6 +12,8 @@
 from agent_term.dispatch_cli import build_pipeline
 from agent_term.events import AgentTermEvent
 from agent_term.matrix_service import normalize_sync_payload
+from agent_term.matrix_state import DEFAULT_STATE_PATH, MatrixStateStore, resolve_matrix_room
+from agent_term.matrix_state import rooms_from_sync_payload
 from agent_term.store import DEFAULT_DB_PATH, EventStore
 
 
@@ -22,6 +24,7 @@ def build_parser() -> argparse.ArgumentParser:
     )
     parser.add_argument("--config", help="Optional AgentTerm JSON config path.")
     parser.add_argument("--db", help="Path to local AgentTerm SQLite event log.")
+    parser.add_argument("--state", default=str(DEFAULT_STATE_PATH), help="Path to Matrix sync state JSON.")
     subparsers = parser.add_subparsers(dest="command", required=True)
 
     send = subparsers.add_parser("send", help="Send a Matrix message through the AgentTerm dispatch pipeline.")
@@ -41,17 +44,25 @@ def build_parser() -> argparse.ArgumentParser:
     sync = subparsers.add_parser("normalize-sync", help="Normalize a Matrix /sync JSON payload.")
     sync.add_argument("payload", help="Path to a Matrix sync payload JSON file, or '-' for stdin.")
     sync.add_argument("--persist", action="store_true", help="Persist normalized events into EventStore.")
+    sync.add_argument("--save-state", action="store_true", help="Persist next_batch and room IDs into Matrix state.")
     sync.add_argument("--sender", default="@agent-term")
     sync.add_argument("--channel", default="!matrix-sync")
 
+    state = subparsers.add_parser("state", help="Show durable Matrix sync state.")
+    state.add_argument("--json", action="store_true", help="Print state as JSON.")
+
     return parser
 
 
 def cmd_send(args: argparse.Namespace) -> int:
     config = load_config(args.config)
     db_path = Path(args.db or config.event_store.path or DEFAULT_DB_PATH)
+    state_store = MatrixStateStore(args.state)
+    state = state_store.load()
+    room_id = resolve_matrix_room(args.room, config, state)
     metadata: dict[str, object] = {
-        "matrix_room_id": args.room,
+        "matrix_room_id": room_id,
+        "matrix_room_alias": args.room if args.room != room_id else None,
         "msgtype": args.msgtype,
         "policy_action": args.policy_action,
     }
@@ -64,7 +75,7 @@ def cmd_send(args: argparse.Namespace) -> int:
         metadata["matrix_e2ee_verified"] = bool(args.matrix_verified)
 
     event = AgentTermEvent(
-        channel=args.room,
+        channel=room_id,
         sender=args.sender,
         kind="matrix_service_send",
         source="matrix-service",
@@ -90,6 +101,7 @@ def cmd_send(args: argparse.Namespace) -> int:
         outcome = build_pipeline(dispatch_args, event, store, config).dispatch(event)
         status = "ok" if outcome.ok else "blocked"
         print(f"matrix_send_status={status}")
+        print(f"matrix_room_id={room_id}")
         if outcome.blocked_reason:
             print(f"blocked_reason={outcome.blocked_reason}")
         print(f"persisted_events={len(outcome.persisted_events)}")
@@ -120,11 +132,30 @@ def cmd_normalize_sync(args: argparse.Namespace) -> int:
             store.close()
         print(f"persisted_events={len(events)}")
 
+    if args.save_state:
+        state_store = MatrixStateStore(args.state)
+        state = state_store.update_rooms(rooms_from_sync_payload(payload))
+        state = state_store.save(state.with_next_batch(batch.next_batch))
+        print(f"matrix_state_next_batch={state.next_batch}")
+        print(f"matrix_state_rooms={len(state.rooms)}")
+
     for event in events:
         print(f"{event.channel}\t{event.sender}\t{event.kind}\t{event.body}")
     return 0
 
 
+def cmd_state(args: argparse.Namespace) -> int:
+    state = MatrixStateStore(args.state).load()
+    if args.json:
+        print(json.dumps(state.to_dict(), indent=2, sort_keys=True))
+        return 0
+    print(f"matrix_state_next_batch={state.next_batch or ''}")
+    print(f"matrix_state_rooms={len(state.rooms)}")
+    for alias, room_id in sorted(state.rooms.items()):
+        print(f"{alias}\t{room_id}")
+    return 0
+
+
 def _load_json_payload(path: str) -> dict[str, Any]:
     if path == "-":
         raw = sys.stdin.read()
@@ -142,6 +173,8 @@ def main(argv: list[str] | None = None) -> int:
         return cmd_send(args)
     if args.command == "normalize-sync":
         return cmd_normalize_sync(args)
+    if args.command == "state":
+        return cmd_state(args)
     raise SystemExit(f"unknown command: {args.command}")
 
 
diff --git a/src/agent_term/matrix_state.py b/src/agent_term/matrix_state.py
new file mode 100644
index 0000000..9ed5d28
--- /dev/null
+++ b/src/agent_term/matrix_state.py
@@ -0,0 +1,119 @@
+"""Durable Matrix sync state and room resolution helpers."""
+
+from __future__ import annotations
+
+import json
+from dataclasses import dataclass, field
+from datetime import UTC, datetime
+from pathlib import Path
+
+from agent_term.config import AgentTermConfig
+
+
+DEFAULT_STATE_PATH = Path(".agent-term/matrix-state.json")
+
+
+@dataclass(frozen=True)
+class MatrixSyncState:
+    """Durable sync cursor and room-alias state for Matrix workflows."""
+
+    next_batch: str | None = None
+    rooms: dict[str, str] = field(default_factory=dict)
+    updated_at: str | None = None
+
+    def to_dict(self) -> dict[str, object]:
+        return {
+            "next_batch": self.next_batch,
+            "rooms": self.rooms,
+            "updated_at": self.updated_at,
+        }
+
+    @classmethod
+    def from_dict(cls, value: dict[str, object]) -> "MatrixSyncState":
+        rooms_raw = value.get("rooms")
+        rooms = rooms_raw if isinstance(rooms_raw, dict) else {}
+        return cls(
+            next_batch=_optional_str(value.get("next_batch")),
+            rooms={str(key): str(room_id) for key, room_id in rooms.items()},
+            updated_at=_optional_str(value.get("updated_at")),
+        )
+
+    def with_next_batch(self, next_batch: str | None) -> "MatrixSyncState":
+        if next_batch is None:
+            return self
+        return MatrixSyncState(
+            next_batch=next_batch,
+            rooms=self.rooms,
+            updated_at=datetime.now(UTC).isoformat(),
+        )
+
+    def with_rooms(self, rooms: dict[str, str]) -> "MatrixSyncState":
+        merged = {**self.rooms, **rooms}
+        return MatrixSyncState(
+            next_batch=self.next_batch,
+            rooms=merged,
+            updated_at=datetime.now(UTC).isoformat(),
+        )
+
+
+class MatrixStateStore:
+    """JSON-backed Matrix sync state store."""
+
+    def __init__(self, path: Path | str = DEFAULT_STATE_PATH) -> None:
+        self.path = Path(path)
+
+    def load(self) -> MatrixSyncState:
+        if not self.path.exists():
+            return MatrixSyncState()
+        with self.path.open("r", encoding="utf-8") as handle:
+            raw = json.load(handle)
+        if not isinstance(raw, dict):
+            raise ValueError("Matrix state file must contain a JSON object")
+        return MatrixSyncState.from_dict(raw)
+
+    def save(self, state: MatrixSyncState) -> MatrixSyncState:
+        self.path.parent.mkdir(parents=True, exist_ok=True)
+        with self.path.open("w", encoding="utf-8") as handle:
+            json.dump(state.to_dict(), handle, indent=2, sort_keys=True)
+            handle.write("\n")
+        return state
+
+    def update_next_batch(self, next_batch: str | None) -> MatrixSyncState:
+        state = self.load().with_next_batch(next_batch)
+        return self.save(state)
+
+    def update_rooms(self, rooms: dict[str, str]) -> MatrixSyncState:
+        state = self.load().with_rooms(rooms)
+        return self.save(state)
+
+
+def resolve_matrix_room(room: str, config: AgentTermConfig, state: MatrixSyncState) -> str:
+    """Resolve a room alias/key to a Matrix room ID when possible."""
+
+    if room in state.rooms:
+        return state.rooms[room]
+    if room in config.matrix.rooms:
+        return config.matrix.rooms[room]
+    for alias, room_id in config.matrix.rooms.items():
+        if room == alias or room == room_id:
+            return room_id
+    return room
+
+
+def rooms_from_sync_payload(payload: dict[str, object]) -> dict[str, str]:
+    """Extract room ID mappings from a Matrix sync payload."""
+
+    rooms: dict[str, str] = {}
+    rooms_raw = payload.get("rooms")
+    if not isinstance(rooms_raw, dict):
+        return rooms
+    joined = rooms_raw.get("join")
+    if not isinstance(joined, dict):
+        return rooms
+    for room_id in joined:
+        rooms[str(room_id)] = str(room_id)
+    return rooms
+
+
+def _optional_str(value: object) -> str | None:
+    return str(value) if value is not None else None
diff --git a/tests/test_matrix_cli.py b/tests/test_matrix_cli.py
index 37885d3..90d4e5a 100644
--- a/tests/test_matrix_cli.py
+++ b/tests/test_matrix_cli.py
@@ -24,6 +24,7 @@ def test_matrix_cli_send_dispatches_policy_admitted_message(tmp_path, capsys):
     captured = capsys.readouterr()
     assert exit_code == 0
     assert "matrix_send_status=ok" in captured.out
+    assert "matrix_room_id=!room:example.org" in captured.out
     assert "persisted_events=3" in captured.out
 
     store = EventStore(db_path)
@@ -40,6 +41,35 @@ def test_matrix_cli_send_dispatches_policy_admitted_message(tmp_path, capsys):
     assert events[-1].metadata["matrix_event_id"] == "$local-1"
 
 
+def test_matrix_cli_send_resolves_room_from_config(tmp_path, capsys):
+    db_path = tmp_path / "events.sqlite3"
+    config_path = tmp_path / "agent-term.json"
+    config_path.write_text(
+        json.dumps(
+            {
+                "eventStore": {"driver": "sqlite", "path": str(db_path)},
+                "matrix": {"rooms": {"sourceosOps": "!sourceos-ops:example.org"}},
+                "localRuntime": {"allowPolicies": ["matrix-service.matrix_service_send"]},
+            }
+        ),
+        encoding="utf-8",
+    )
+
+    exit_code = main(["--config", str(config_path), "send", "sourceosOps", "Hello"])
+
+    captured = capsys.readouterr()
+    assert exit_code == 0
+    assert "matrix_room_id=!sourceos-ops:example.org" in captured.out
+
+    store = EventStore(db_path)
+    try:
+        events = store.tail(limit=10)
+    finally:
+        store.close()
+    assert events[0].channel == "!sourceos-ops:example.org"
+    assert events[0].metadata["matrix_room_alias"] == "sourceosOps"
+
+
 def test_matrix_cli_send_blocks_unverified_encrypted_sensitive_context(tmp_path, capsys):
     db_path = tmp_path / "events.sqlite3"
 
@@ -146,3 +176,69 @@ def test_matrix_cli_normalize_sync_persists_events(tmp_path, capsys):
     assert len(events) == 1
     assert events[0].kind == "matrix_membership"
     assert events[0].metadata["matrix_membership"] == "join"
+
+
+def test_matrix_cli_normalize_sync_saves_state(tmp_path, capsys):
+    db_path = tmp_path / "events.sqlite3"
+    state_path = tmp_path / "matrix-state.json"
+    payload_path = tmp_path / "sync.json"
+    payload_path.write_text(
+        json.dumps(
+            {
+                "next_batch": "batch-3",
+                "rooms": {
+                    "join": {
+                        "!room:example.org": {
+                            "timeline": {
+                                "events": [
+                                    {
+                                        "event_id": "$event1",
+                                        "sender": "@operator:example.org",
+                                        "type": "m.room.message",
+                                        "content": {"body": "hello"},
+                                    }
+                                ]
+                            }
+                        }
+                    }
+                },
+            }
+        ),
+        encoding="utf-8",
+    )
+
+    exit_code = main(
+        [
+            "--db",
+            str(db_path),
+            "--state",
+            str(state_path),
+            "normalize-sync",
+            str(payload_path),
+            "--save-state",
+        ]
+    )
+
+    captured = capsys.readouterr()
+    assert exit_code == 0
+    assert "matrix_state_next_batch=batch-3" in captured.out
+    assert "matrix_state_rooms=1" in captured.out
+    state = json.loads(state_path.read_text(encoding="utf-8"))
+    assert state["next_batch"] == "batch-3"
+    assert state["rooms"] == {"!room:example.org": "!room:example.org"}
+
+
+def test_matrix_cli_state_prints_state(tmp_path, capsys):
+    state_path = tmp_path / "matrix-state.json"
+    state_path.write_text(
+        json.dumps({"next_batch": "batch-4", "rooms": {"sourceosOps": "!room"}}),
+        encoding="utf-8",
+    )
+
+    exit_code = main(["--state", str(state_path), "state"])
+
+    captured = capsys.readouterr()
+    assert exit_code == 0
+    assert "matrix_state_next_batch=batch-4" in captured.out
+    assert "matrix_state_rooms=1" in captured.out
+    assert "sourceosOps\t!room" in captured.out
diff --git a/tests/test_matrix_state.py b/tests/test_matrix_state.py
new file mode 100644
index 0000000..c7cc117
--- /dev/null
+++ b/tests/test_matrix_state.py
@@ -0,0 +1,69 @@
+import json
+
+from agent_term.config import config_from_dict
+from agent_term.matrix_state import MatrixStateStore, MatrixSyncState, resolve_matrix_room
+from agent_term.matrix_state import rooms_from_sync_payload
+
+
+def test_matrix_state_store_round_trips_next_batch_and_rooms(tmp_path):
+    state_path = tmp_path / "matrix-state.json"
+    store = MatrixStateStore(state_path)
+
+    saved = store.save(
+        MatrixSyncState(next_batch="batch-1", rooms={"sourceosOps": "!room:example.org"})
+    )
+    loaded = store.load()
+
+    assert saved.next_batch == "batch-1"
+    assert loaded.next_batch == "batch-1"
+    assert loaded.rooms == {"sourceosOps": "!room:example.org"}
+    assert state_path.exists()
+
+
+def test_matrix_state_updates_next_batch_without_dropping_rooms(tmp_path):
+    store = MatrixStateStore(tmp_path / "matrix-state.json")
+    store.save(MatrixSyncState(next_batch="batch-1", rooms={"sourceosOps": "!room"}))
+
+    updated = store.update_next_batch("batch-2")
+
+    assert updated.next_batch == "batch-2"
+    assert updated.rooms == {"sourceosOps": "!room"}
+    assert updated.updated_at is not None
+
+
+def test_resolve_matrix_room_prefers_state_then_config_then_literal():
+    config = config_from_dict({"matrix": {"rooms": {"sourceosOps": "!config:example.org"}}})
+    state = MatrixSyncState(rooms={"sourceosOps": "!state:example.org"})
+
+    assert resolve_matrix_room("sourceosOps", config, state) == "!state:example.org"
+    assert resolve_matrix_room("!config:example.org", config, MatrixSyncState()) == "!config:example.org"
+    assert resolve_matrix_room("unknown", config, state) == "unknown"
+
+
+def test_rooms_from_sync_payload_extracts_joined_room_ids():
+    rooms = rooms_from_sync_payload(
+        {
+            "rooms": {
+                "join": {
+                    "!one:example.org": {"timeline": {"events": []}},
+                    "!two:example.org": {"timeline": {"events": []}},
+                }
+            }
+        }
+    )
+
+    assert rooms == {
+        "!one:example.org": "!one:example.org",
+        "!two:example.org": "!two:example.org",
+    }
+
+
+def test_state_file_is_json_object(tmp_path):
+    state_path = tmp_path / "matrix-state.json"
+    store = MatrixStateStore(state_path)
+    store.save(MatrixSyncState(next_batch="batch-1", rooms={"!room": "!room"}))
+
+    raw = json.loads(state_path.read_text(encoding="utf-8"))
+
+    assert raw["next_batch"] == "batch-1"
+    assert raw["rooms"] == {"!room": "!room"}