perf(ci): fetch multiple agent ledger artifacts concurrently

scripts/ci/agent_mention_router.py

@@ -4,6 +4,7 @@
 from __future__ import annotations
 
 import argparse
+import concurrent.futures
 import hashlib
 import json
 import os
@@ -463,24 +464,47 @@ def dispatched_agents(
     artifact_cache = (
         ledger_artifact_cache if ledger_artifact_cache is not None else {}
     )
+
+    def _fetch_agent(agent: str) -> None:
+        """Fetch and cache the exact-name artifact lookup for one agent."""
+        artifact_name = agent_ledger_artifact_name(request, agent)
+        response = dispatch_client.request(
+            [
+                LEDGER_ARTIFACTS_ENDPOINT,
+                "-X",
+                "GET",
+                "-f",
+                f"name={artifact_name}",
+                "-f",
+                "per_page=100",
+            ]
+        )
+        artifact_cache[artifact_name] = bool(
+            _artifact_records(response, expected_name=artifact_name)
+        )
+
+    agents_to_fetch = [
+        agent
+        for agent in candidates
+        if agent_ledger_artifact_name(request, agent) not in artifact_cache
+    ]
+    if len(agents_to_fetch) <= 1:
+        for agent in agents_to_fetch:
+            _fetch_agent(agent)
+    else:
+        # Bounded concurrency for an otherwise-sequential N+1 network fetch.
+        # list(executor.map(...)) already blocks until every submitted call
+        # finishes (or raises) before this function proceeds, so shutdown's
+        # own wait has nothing left to wait for on the success path.
+        executor = concurrent.futures.ThreadPoolExecutor(max_workers=5)
+        try:
+            list(executor.map(_fetch_agent, agents_to_fetch))
+        finally:
+            executor.shutdown(wait=False, cancel_futures=True)
+
     for agent in candidates:
         artifact_name = agent_ledger_artifact_name(request, agent)
-        if artifact_name not in artifact_cache:
-            response = dispatch_client.request(
-                [
-                    LEDGER_ARTIFACTS_ENDPOINT,
-                    "-X",
-                    "GET",
-                    "-f",
-                    f"name={artifact_name}",
-                    "-f",
-                    "per_page=100",
-                ]
-            )
-            artifact_cache[artifact_name] = bool(
-                _artifact_records(response, expected_name=artifact_name)
-            )
-        if artifact_cache[artifact_name]:
+        if artifact_cache.get(artifact_name):
             observed.add(agent)
     return frozenset(observed)
 

tests/test_agent_mention_router.py

@@ -744,3 +744,57 @@ def test_load_event_and_main_paths(tmp_path: Path, monkeypatch, capsys) -> None:
     )
     assert module.main(["--event-path", str(valid_path), "--dry-run"]) == 0
     assert captured[0][1]["dry_run"] is True
+
+
+def test_dispatched_agents_fetches_multiple_candidates_concurrently() -> None:
+    """More than one uncached agent uses the bounded thread-pool fetch path."""
+
+    module = load_module()
+    request = module.parse_event(
+        event("@cwl-noema-review @opencode-agent")
+    )
+    assert request is not None
+    client = FakeClient()
+
+    observed = module.dispatched_agents(request, client)
+
+    assert observed == frozenset()
+    artifact_calls = [
+        args for args, _ in client.calls if args[0].endswith("/actions/artifacts")
+    ]
+    assert len(artifact_calls) == 2
+
+
+def test_dispatched_agents_single_candidate_skips_thread_pool() -> None:
+    """Exactly one uncached agent stays on the plain sequential path."""
+
+    module = load_module()
+    request = module.parse_event(event("@opencode-agent"))
+    assert request is not None
+    client = FakeClient()
+
+    observed = module.dispatched_agents(request, client)
+
+    assert observed == frozenset()
+    assert len(client.calls) == 1
+
+
+def test_dispatched_agents_reuses_the_caller_owned_cache() -> None:
+    """A pre-populated cache entry never triggers a redundant API call."""
+
+    module = load_module()
+    request = module.parse_event(
+        event("@cwl-noema-review @opencode-agent")
+    )
+    assert request is not None
+    client = FakeClient()
+    cached_name = module.agent_ledger_artifact_name(request, "cwl-noema-review")
+
+    observed = module.dispatched_agents(
+        request,
+        client,
+        ledger_artifact_cache={cached_name: True},
+    )
+
+    assert observed == frozenset({"cwl-noema-review"})
+    assert len(client.calls) == 1