fix(code): exclude managed bin dir from agent picker (#4190)

Fix the `/agents` picker listing the internal `bin` directory (managed
ripgrep install) as a selectable agent.

---

The `/agents` picker lists every real, non-dot subdirectory under
`~/.deepagents/`, filtering only symlinks and dot-prefixed names. The
managed ripgrep install dir (`~/.deepagents/bin`,
`managed_tools.BIN_DIR`) therefore showed up as a phantom `bin` agent.
This adds a reserved-name filter to `_is_agent_dir_entry`, sourced from
`BIN_DIR.name` to keep a single source of truth.

Made by [Open
SWE](https://openswe.vercel.app/agents/3cd7dda7-db49-2afd-b636-d678ecc65dc0)

---------

Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>

libs/code/deepagents_code/agent.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import functools
 import logging
 import os
 import re
@@ -438,17 +439,32 @@ def load_async_subagents(config_path: Path | None = None) -> list[AsyncSubAgent]
     return agents
 
 
+@functools.lru_cache(maxsize=1)
+def _reserved_agent_dir_names() -> frozenset[str]:
+    """Return non-agent directory names reserved by the app under `~/.deepagents/`.
+
+    `bin/` holds the managed `rg` binary (`managed_tools.BIN_DIR`) and must
+    never appear in the agent picker. The name is derived from `BIN_DIR` so it
+    stays a single source of truth rather than being hardcoded here. The result
+    is cached since the reserved set is constant for the process.
+    """
+    from deepagents_code.managed_tools import BIN_DIR
+
+    return frozenset({BIN_DIR.name})
+
+
 def _is_agent_dir_entry(entry: Path) -> bool:
     """Return whether a `~/.deepagents/` entry should be listed as an agent.
 
-    Filters out symlinks (so dangling links don't masquerade as agents)
-    and dot-prefixed names — `.state/` (app internal state) plus any
-    other hidden directory the user may have placed there.
+    Filters out symlinks (so dangling links don't masquerade as agents),
+    dot-prefixed names — `.state/` (app internal state) plus any other
+    hidden directory the user may have placed there — and reserved names
+    the app owns (e.g. `bin/`, the managed-binary install dir).
 
     `OSError` from `is_dir`/`is_symlink` propagates so callers can log
     with the failing entry's name as context.
     """
-    if entry.name.startswith("."):
+    if entry.name.startswith(".") or entry.name in _reserved_agent_dir_names():
         return False
     return entry.is_dir() and not entry.is_symlink()
 
@@ -458,8 +474,9 @@ def get_available_agent_names() -> list[str]:
 
     Scans the user's `.deepagents` directory and returns each real
     subdirectory found there. Symlinks excluded so a dangling link does not
-    masquerade as an agent. Dot-prefixed entries (e.g., `.state/`) are
-    skipped so internal app state never appears as an agent.
+    masquerade as an agent. Dot-prefixed entries (e.g., `.state/`) and
+    reserved app-owned directories (e.g., `bin/`, the managed-binary install
+    dir) are skipped so internal state never appears as an agent.
 
     Filesystem errors (missing parent, permission denied, broken entries) are
     logged and surfaced as an empty list rather than raised — the caller shows

libs/code/tests/unit_tests/test_agent.py

@@ -30,6 +30,7 @@ from deepagents_code.agent import (
     _format_task_description,
     _format_web_search_description,
     _format_write_file_description,
+    _reserved_agent_dir_names,
     _sanitize_agent_message_name,
     _should_interrupt_tool_call,
     build_model_identity_section,
@@ -40,6 +41,7 @@ from deepagents_code.agent import (
     load_async_subagents,
 )
 from deepagents_code.config import Settings, get_glyphs
+from deepagents_code.managed_tools import BIN_DIR
 from deepagents_code.project_utils import ProjectContext
 
 
@@ -2933,6 +2935,25 @@ class TestGetAvailableAgentNames:
         with patch("deepagents_code.agent.settings", _mock_agents_dir(agents_dir)):
             assert get_available_agent_names() == ["agent"]
 
+    def test_ignores_reserved_bin_dir(self, tmp_path: Path) -> None:
+        """The managed-binary install dir is excluded from the agent list.
+
+        The reserved dir name is derived from `BIN_DIR.name` rather than the
+        literal `bin` so a future rename of `BIN_DIR` keeps this test exercising
+        the actual reserved name instead of a stale string.
+        """
+        agents_dir = tmp_path / "agents"
+        agents_dir.mkdir()
+        (agents_dir / "agent").mkdir()
+        (agents_dir / BIN_DIR.name).mkdir()
+
+        with patch("deepagents_code.agent.settings", _mock_agents_dir(agents_dir)):
+            assert get_available_agent_names() == ["agent"]
+
+    def test_reserved_agent_dir_names_includes_bin_dir(self) -> None:
+        """The reserved-name set is sourced from `BIN_DIR.name` (single source)."""
+        assert _reserved_agent_dir_names() == frozenset({BIN_DIR.name})
+
     def test_permission_error_returns_empty(self, tmp_path: Path) -> None:
         """PermissionError on iterdir → logged + empty list, not raised."""
         agents_dir = tmp_path / "agents"