diff --git a/cueapi/cli.py b/cueapi/cli.py
index 482c2d4..d8e4a5f 100644
--- a/cueapi/cli.py
+++ b/cueapi/cli.py
@@ -454,8 +454,24 @@ def delete(ctx: click.Context, cue_id: str, yes: bool) -> None:
 @click.argument("cue_id")
 @click.option("--payload-override", "payload_override", default=None, help="JSON payload override for this fire only")
 @click.option("--merge-strategy", "merge_strategy", type=click.Choice(["merge", "replace"]), default=None, help="How payload-override combines with the cue's stored payload (default: merge, server-side)")
+@click.option(
+    "--send-at",
+    "send_at",
+    default=None,
+    help=(
+        "Optional UTC timestamp (ISO 8601) to schedule this fire for the future. "
+        "Server gates dispatch until send-at <= now. Past timestamps are treated as "
+        "'fire now' (idempotent — no error). Hosted PR #618."
+    ),
+)
 @click.pass_context
-def fire(ctx: click.Context, cue_id: str, payload_override: Optional[str], merge_strategy: Optional[str]) -> None:
+def fire(
+    ctx: click.Context,
+    cue_id: str,
+    payload_override: Optional[str],
+    merge_strategy: Optional[str],
+    send_at: Optional[str],
+) -> None:
     """Fire an existing cue immediately, optionally overriding its payload."""
     body: dict = {}
     if payload_override:
@@ -465,6 +481,8 @@ def fire(ctx: click.Context, cue_id: str, payload_override: Optional[str], merge
             raise click.UsageError("--payload-override must be valid JSON")
     if merge_strategy:
         body["merge_strategy"] = merge_strategy
+    if send_at:
+        body["send_at"] = send_at
 
     try:
         with CueAPIClient(api_key=ctx.obj.get("api_key"), profile=ctx.obj.get("profile")) as client:
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 644c5cf..619617b 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -2160,3 +2160,81 @@ def test_top_level_help_lists_messages():
     result = runner.invoke(main, ["--help"])
     assert result.exit_code == 0
     assert "messages" in result.output
+
+
+# --- fire --send-at (hosted PR #618 port) ---
+
+
+class _FireSendAtClient:
+    def __init__(self):
+        self.last_body: Optional[dict] = None
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *_):
+        pass
+
+    def post(self, path, json=None, **_):
+        self.last_body = json
+        class _R:
+            status_code = 200
+            def json(self):
+                return {"id": "exec_test", "scheduled_for": "2026-05-04T20:00:00Z"}
+        return _R()
+
+
+def _patch_fire_client(monkeypatch, holder):
+    import cueapi.cli as cli_mod
+
+    def fake_factory(*_, **__):
+        holder["client"] = _FireSendAtClient()
+        return holder["client"]
+
+    monkeypatch.setattr(cli_mod, "CueAPIClient", fake_factory)
+
+
+def test_fire_help_lists_send_at():
+    result = runner.invoke(main, ["fire", "--help"])
+    assert result.exit_code == 0
+    assert "--send-at" in result.output
+
+
+def test_fire_send_at_passed_to_body(monkeypatch):
+    holder: dict = {}
+    _patch_fire_client(monkeypatch, holder)
+    result = runner.invoke(
+        main,
+        ["fire", "cue_x", "--send-at", "2026-05-04T20:00:00Z"],
+    )
+    assert result.exit_code == 0, result.output
+    assert holder["client"].last_body == {"send_at": "2026-05-04T20:00:00Z"}
+
+
+def test_fire_omits_send_at_when_unset(monkeypatch):
+    # Pin: when --send-at isn't passed, the body must not include the key.
+    holder: dict = {}
+    _patch_fire_client(monkeypatch, holder)
+    result = runner.invoke(main, ["fire", "cue_x"])
+    assert result.exit_code == 0
+    assert "send_at" not in (holder["client"].last_body or {})
+
+
+def test_fire_combines_send_at_with_payload_override(monkeypatch):
+    holder: dict = {}
+    _patch_fire_client(monkeypatch, holder)
+    result = runner.invoke(
+        main,
+        [
+            "fire", "cue_x",
+            "--payload-override", '{"task": "demo"}',
+            "--merge-strategy", "replace",
+            "--send-at", "2026-05-04T22:00:00Z",
+        ],
+    )
+    assert result.exit_code == 0
+    assert holder["client"].last_body == {
+        "payload_override": {"task": "demo"},
+        "merge_strategy": "replace",
+        "send_at": "2026-05-04T22:00:00Z",
+    }