From 48b2346e33aea7577d6d41dd04301033c8391b32 Mon Sep 17 00:00:00 2001
From: gdibben <gethin.dibben@langchain.dev>
Date: Thu, 8 Oct 2026 07:57:05 +0100
Subject: [PATCH] feat(cli): add --json to deploy listeners list

The table output isn't scriptable, so a deploy automation pipeline
has no reliable way to extract a listener's id to pass to
--listener-id. --json prints the listeners as a JSON array instead
(an empty array when there are none, so callers never need to
special-case the human-readable "no listeners" message).
---
 libs/cli/langgraph_cli/deploy.py          | 14 ++++-
 libs/cli/tests/unit_tests/cli/test_cli.py | 73 +++++++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/libs/cli/langgraph_cli/deploy.py b/libs/cli/langgraph_cli/deploy.py
index f04e9b31a..7507482c1 100644
--- a/libs/cli/langgraph_cli/deploy.py
+++ b/libs/cli/langgraph_cli/deploy.py
@@ -2518,6 +2518,13 @@ def deploy_listeners() -> None:
 
 @OPT_HOST_API_KEY
 @OPT_HOST_URL
+@click.option(
+    "--json",
+    "json_output",
+    is_flag=True,
+    default=False,
+    help="Emit the listeners as a JSON array instead of a table.",
+)
 @deploy_listeners.command(
     "list",
     help=(
@@ -2526,11 +2533,16 @@ def deploy_listeners() -> None:
         "--listener-id <id>` to deploy through it."
     ),
 )
-def deploy_listeners_list(api_key: str | None, host_url: str | None) -> None:
+def deploy_listeners_list(
+    api_key: str | None, host_url: str | None, json_output: bool
+) -> None:
     client = _create_host_backend_client(host_url, api_key)
     listeners = _call_host_backend_with_optional_tenant(
         client, lambda c: c.list_listeners()
     )
+    if json_output:
+        click.echo(json_mod.dumps(listeners))
+        return
     if not listeners:
         click.echo("No listeners found for this workspace.")
         return
diff --git a/libs/cli/tests/unit_tests/cli/test_cli.py b/libs/cli/tests/unit_tests/cli/test_cli.py
index 7b3441877..01838dec2 100644
--- a/libs/cli/tests/unit_tests/cli/test_cli.py
+++ b/libs/cli/tests/unit_tests/cli/test_cli.py
@@ -535,6 +535,79 @@ def test_deploy_listeners_list_command_no_results(monkeypatch) -> None:
     assert result.output.strip() == "No listeners found for this workspace."
 
 
+def test_deploy_listeners_list_command_json(monkeypatch) -> None:
+    runner = CliRunner()
+
+    listeners = [
+        {
+            "id": "listener-1",
+            "compute_id": "prod-cluster",
+            "compute_config": {"k8s_namespaces": ["agents"]},
+        },
+        {
+            "id": "listener-2",
+            "compute_id": "multi-cluster",
+            "compute_config": {"k8s_namespaces": ["agents", "agents-staging"]},
+        },
+    ]
+
+    class FakeClient:
+        def __init__(self, host_url: str, api_key: str, tenant_id: str | None = None):
+            pass
+
+        def list_listeners(self):
+            return listeners
+
+    monkeypatch.setattr(deploy_module, "HostBackendClient", FakeClient)
+
+    result = runner.invoke(
+        cli,
+        [
+            "deploy",
+            "listeners",
+            "list",
+            "--json",
+            "--api-key",
+            "test-key",
+            "--host-url",
+            "https://api.example.com",
+        ],
+    )
+
+    assert result.exit_code == 0, result.output
+    assert json.loads(result.output) == listeners
+
+
+def test_deploy_listeners_list_command_json_no_results(monkeypatch) -> None:
+    runner = CliRunner()
+
+    class FakeClient:
+        def __init__(self, host_url: str, api_key: str, tenant_id: str | None = None):
+            pass
+
+        def list_listeners(self):
+            return []
+
+    monkeypatch.setattr(deploy_module, "HostBackendClient", FakeClient)
+
+    result = runner.invoke(
+        cli,
+        [
+            "deploy",
+            "listeners",
+            "list",
+            "--json",
+            "--api-key",
+            "test-key",
+            "--host-url",
+            "https://api.example.com",
+        ],
+    )
+
+    assert result.exit_code == 0, result.output
+    assert json.loads(result.output) == []
+
+
 def test_deploy_revisions_list_command(monkeypatch) -> None:
     runner = CliRunner()
     captured: dict[str, str] = {}