fix(agents): anchor agent-name validation against a trailing newline (#5960)

* fix(agents): anchor agent-name validation against a trailing newline

Two copies of the shared ^[A-Za-z0-9-]+$ grammar still used re.match,
whose $ also matches before a final newline, while every other copy uses
fullmatch. POST /api/agents {"name": "reviewer\n"} therefore passed the
router guard and died inside the strict file store as an HTTP 500, and
DeerMem accepted the same name as an agents/{name}/facts directory.

* test(agents): state which trailing-newline params the regression actually covered

.match only accepted "reviewer\n" on main; "reviewer\n\n" and "reviewer \n"
were already rejected, so the docstrings should not read as if every param in
these parametrizations was broken before the fix.

backend/app/gateway/routers/agents.py

@@ -108,7 +108,7 @@ def _validate_agent_name(name: str) -> None:
     Raises:
         HTTPException: 422 if the name is invalid.
     """
-    if not AGENT_NAME_PATTERN.match(name):
+    if not AGENT_NAME_PATTERN.fullmatch(name):
         raise HTTPException(
             status_code=422,
             detail=f"Invalid agent name '{name}'. Must match ^[A-Za-z0-9-]+$ (letters, digits, and hyphens only).",

backend/packages/harness/deerflow/agents/memory/backends/deermem/deermem/core/paths.py

@@ -57,7 +57,7 @@ def validate_agent_name(name: str) -> None:
     """Validate that the agent name is safe to use in filesystem paths."""
     if not name:
         raise ValueError("Agent name must be a non-empty string.")
-    if name != DEFAULT_AGENT_BUCKET and not AGENT_NAME_PATTERN.match(name):
+    if name != DEFAULT_AGENT_BUCKET and not AGENT_NAME_PATTERN.fullmatch(name):
         raise ValueError(f"Invalid agent name {name!r}: names must match {AGENT_NAME_PATTERN.pattern}")
 
 

backend/tests/test_custom_agent.py

@@ -12,7 +12,7 @@ from fastapi.testclient import TestClient
 
 from app.gateway.routers.agents import AGENT_NAME_PATTERN as GATEWAY_AGENT_NAME_PATTERN
 from deerflow.agents.memory.backends.deermem.deermem.core.paths import AGENT_NAME_PATTERN as DEERMEM_AGENT_NAME_PATTERN
-from deerflow.agents.memory.backends.deermem.deermem.core.paths import DEFAULT_AGENT_BUCKET, validate_agent_name
+from deerflow.agents.memory.backends.deermem.deermem.core.paths import DEFAULT_AGENT_BUCKET, agent_facts_directory, validate_agent_name
 from deerflow.config.agents_api_config import AgentsApiConfig, get_agents_api_config, set_agents_api_config
 
 # ---------------------------------------------------------------------------
@@ -26,6 +26,24 @@ def test_reserved_memory_bucket_stays_outside_both_public_agent_patterns() -> No
     validate_agent_name(DEFAULT_AGENT_BUCKET)  # Internal storage sentinel remains usable.
 
 
+@pytest.mark.parametrize("name", ["reviewer\n", "reviewer \n"])
+def test_agent_name_validation_rejects_trailing_newline(name: str) -> None:
+    """``$`` in ``^[A-Za-z0-9-]+$`` also matches before a final newline.
+
+    Only ``fullmatch`` anchors it, so DeerMem's inlined copy of the host's
+    agent-name grammar accepted ``"reviewer\\n"`` and used it as a directory
+    name — which the host's own strict validator then refuses forever.
+
+    ``"reviewer \\n"`` was already rejected by ``.match`` (the space falls
+    outside the class, so the match never reaches ``$``); it is parametrized
+    here to pin the grammar, not because it regressed.
+    """
+    with pytest.raises(ValueError, match="Invalid agent name"):
+        validate_agent_name(name)
+    with pytest.raises(ValueError, match="Invalid agent name"):
+        agent_facts_directory(Path("memory.json"), name)
+
+
 def _make_paths(base_dir: Path):
     """Return a Paths instance pointing to base_dir."""
     from deerflow.config.paths import Paths
@@ -609,6 +627,18 @@ class TestAgentsAPI:
         assert agent_client.put("/api/agents/reviewer", json={"display_name": display_name}).status_code == 422
         assert agent_client.get("/api/agents/reviewer").json()["display_name"] == "🦌" * 100
 
+    @pytest.mark.parametrize("name", ["reviewer\n", "reviewer\n\n"])
+    def test_trailing_newline_in_agent_name_is_rejected(self, agent_client, name):
+        """The router's ``AGENT_NAME_PATTERN.match`` accepted ``"reviewer\\n"`` and the store 500'd.
+
+        ``$`` matches before a single trailing newline, so that one param reached
+        the file store, which validates the same grammar with ``fullmatch``.
+        ``"reviewer\\n\\n"`` was already rejected by ``.match`` on main; it is
+        parametrized to pin the grammar, not because it regressed.
+        """
+        assert agent_client.post("/api/agents", json={"name": name}).status_code == 422
+        assert agent_client.get("/api/agents").json()["agents"] == []
+
     def test_display_name_round_trip_keeps_stable_identity(self, agent_client):
         response = agent_client.post("/api/agents", json={"name": "code-reviewer", "display_name": "  代码审查助手  "})
         assert response.status_code == 201