MCP tool discovery missing in Desktop/TUI/Dashboard sessions

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

• #44512 fix(desktop): load MCP tools for dashboard /api/ws backends

  merged to main

  files: hermes_cli/main.py, tests/hermes_cli/test_dashboard_unified_launch.py, tests/test_tui_gateway_server.py, tui_gateway/server.py

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  • hermes_cli/main.py

    @@ -10431,6 +10431,26 @@ def cmd_dashboard(args):
             # the missing-provider state if it matters.
             print(f"⚠ Plugin discovery failed: {exc}", file=sys.stderr)
     
    +    # Desktop chat uses the dashboard's in-process /api/ws gateway, which builds
    +    # agents via tui_gateway.server._make_agent.  That path only snapshots the
    +    # tool registry — it never starts MCP discovery (the stdio TUI does that in
    +    # tui_gateway/entry.py, which the dashboard process doesn't run).  Without
    +    # this, a profile's configured MCP servers never connect, so desktop
    +    # sessions show no MCP tools.  Spawn discovery in the background here so a
    +    # slow/dead server can't block dashboard startup.
    +    try:
    +        from hermes_cli.mcp_startup import start_background_mcp_discovery
    +
    +        start_background_mcp_discovery(
    +            logger=logger,
    +            thread_name="dashboard-mcp-discovery",
    +        )
    +    except Exception:
    +        logger.debug(
    +            "Background MCP tool discovery failed at dashboard startup",
    +            exc_info=True,
    +        )
    +
         from hermes_cli.web_server import start_server
     
         # The in-browser Chat tab (the embedded TUI over PTY/WebSocket) is always

  • tests/hermes_cli/test_dashboard_unified_launch.py

    @@ -128,3 +128,45 @@ def test_reexec_child_does_not_reroute(self, main_mod, monkeypatch):
             with pytest.raises((SystemExit, AttributeError, ImportError, TypeError)):
                 main_mod.cmd_dashboard(_args(open_profile="worker_x"))
             assert execs == []
    +
    +    def test_dashboard_starts_mcp_discovery_for_ws_backend(self, main_mod, monkeypatch):
    +        """The dashboard process serves the /api/ws gateway but never runs
    +        tui_gateway/entry.py, so it must kick off MCP discovery itself or
    +        desktop sessions never see a profile's MCP tools."""
    +        monkeypatch.setattr(
    +            "hermes_cli.profiles.get_active_profile_name", lambda: "default"
    +        )
    +        monkeypatch.delenv("HERMES_WEB_DIST", raising=False)
    +        monkeypatch.setattr(main_mod, "_sync_bundled_skills_quietly", lambda: None)
    +        monkeypatch.setattr(main_mod, "_build_web_ui", lambda *_a, **_k: True)
    +        monkeypatch.setitem(sys.modules, "fastapi", types.SimpleNamespace())
    +        monkeypatch.setitem(sys.modules, "uvicorn", types.SimpleNamespace())
    +        monkeypatch.setitem(
    +            sys.modules,
    +            "hermes_logging",
    +            types.SimpleNamespace(setup_logging=lambda **_k: None),
    +        )
    +        monkeypatch.setitem(
    +            sys.modules,
    +            "hermes_cli.plugins",
    +            types.SimpleNamespace(discover_plugins=lambda: None),
    +        )
    +        calls = []
    +        monkeypatch.setattr(
    +            "hermes_cli.mcp_startup.start_background_mcp_discovery",
    +            lambda **kwargs: calls.append(kwargs),
    +        )
    +        monkeypatch.setitem(
    +            sys.modules,
    +            "hermes_cli.web_server",
    +            types.SimpleNamespace(start_server=lambda **_kwargs: None),
    +        )
    +
    +        main_mod.cmd_dashboard(_args())
    +
    +        assert calls == [
    +            {
    +                "logger": main_mod.logger,
    +                "thread_name": "dashboard-mcp-discovery",
    +            }
    +        ]

  • tests/test_tui_gateway_server.py

    @@ -6096,6 +6096,24 @@ def test_make_agent_reads_nested_max_turns(monkeypatch):
         assert mock_agent.call_args.kwargs["max_iterations"] == 200
     
     
    +def test_make_agent_waits_for_shared_mcp_discovery(monkeypatch):
    +    _setup_make_agent_mocks(monkeypatch, {})
    +    waited = []
    +
    +    from hermes_cli import mcp_startup
    +
    +    monkeypatch.setattr(
    +        mcp_startup,
    +        "wait_for_mcp_discovery",
    +        lambda timeout=0.75: waited.append(timeout),
    +    )
    +
    +    with patch("run_agent.AIAgent"):
    +        server._make_agent("sid1", "key1")
    +
    +    assert waited == [0.75]
    +
    +
     def test_make_agent_nested_max_turns_takes_priority(monkeypatch):
         _setup_make_agent_mocks(
             monkeypatch, {"agent": {"max_turns": 500}, "max_turns": 100}

  • tui_gateway/server.py

    @@ -3072,11 +3072,17 @@ def _make_agent(
         from hermes_cli.runtime_provider import resolve_runtime_provider
     
         # MCP tool discovery runs in a background daemon thread at startup so a
    -    # dead server can't freeze the shell (see tui_gateway/entry.py).  The agent
    -    # snapshots its tool list once here and never re-reads it, so briefly wait
    -    # for in-flight discovery to land before building — bounded, so a slow/dead
    -    # server still can't block.  No-op once discovery has finished (every build
    -    # after the first during a slow startup).
    +    # dead server can't freeze the shell.  The agent snapshots its tool list
    +    # once here and never re-reads it, so briefly wait for in-flight discovery
    +    # to land before building — bounded, so a slow/dead server still can't
    +    # block. Dashboard /api/ws uses hermes_cli.mcp_startup; TUI stdio keeps
    +    # its existing tui_gateway.entry-owned thread.
    +    try:
    +        from hermes_cli.mcp_startup import wait_for_mcp_discovery
    +
    +        wait_for_mcp_discovery()
    +    except Exception:
    +        pass
         try:
             from tui_gateway.entry import wait_for_mcp_discovery
     

• #54161 fix(tui): start MCP discovery for websocket sessions (#38945)

  merged to main

  files: infographic/mcp-ws-discovery/infographic.png, tests/test_tui_gateway_ws.py, tui_gateway/ws.py

• #61949 fix(tui): discover MCP tools in slash workers

  merged to main

  files: tests/tui_gateway/test_slash_worker_mcp_discovery.py, tui_gateway/slash_worker.py

  Show the diff

  • tests/tui_gateway/test_slash_worker_mcp_discovery.py

    @@ -0,0 +1,105 @@
    +"""Integration coverage for profile-local MCP discovery in slash workers."""
    +
    +from __future__ import annotations
    +
    +import json
    +import os
    +from pathlib import Path
    +import queue
    +import subprocess
    +import sys
    +import textwrap
    +import threading
    +
    +import pytest
    +import yaml
    +
    +pytest.importorskip("mcp.server.fastmcp")
    +
    +
    +def test_profile_local_mcp_tool_is_visible_in_slash_worker(tmp_path):
    +    profile_home = tmp_path / "profile-home"
    +    profile_home.mkdir()
    +    marker = "profile-local-61922"
    +    server = tmp_path / "fastmcp_probe.py"
    +    server.write_text(
    +        textwrap.dedent(
    +            f"""
    +            from mcp.server.fastmcp import FastMCP
    +
    +            mcp = FastMCP("profileprobe")
    +
    +            @mcp.tool()
    +            def hermes_61922_profile_probe() -> str:
    +                return {marker!r}
    +
    +            if __name__ == "__main__":
    +                mcp.run(transport="stdio")
    +            """
    +        ),
    +        encoding="utf-8",
    +    )
    +    (profile_home / "config.yaml").write_text(
    +        yaml.safe_dump(
    +            {
    +                "mcp_servers": {
    +                    "profileprobe": {
    +                        "enabled": True,
    +                        "command": sys.executable,
    +                        "args": [str(server)],
    +                    }
    +                }
    +            }
    +        ),
    +        encoding="utf-8",
    +    )
    +
    +    env = os.environ.copy()
    +    for key in list(env):
    +        if key.endswith("_API_KEY") or key.endswith("_TOKEN"):
    +            env.pop(key)
    +    env["HERMES_HOME"] = str(profile_home)
    +    env["PYTHONPATH"] = str(Path(__file__).resolve().parents[2])
    +    env["HERMES_SLASH_WATCHDOG_GRACE_S"] = "0"
    +    env["HERMES_SLASH_WATCHDOG_POLL_S"] = "0.05"
    +    proc = subprocess.Popen(
    +        [
    +            sys.executable,
    +            "-u",
    +            "-m",
    +            "tui_gateway.slash_worker",
    +            "--session-key",
    +            "agent:main:tui:dm:mcp-profile-test",
    +        ],
    +        stdin=subprocess.PIPE,
    +        stdout=subprocess.PIPE,
    +        stderr=subprocess.PIPE,
    +        text=True,
    +        env=env,
    +        cwd=tmp_path,
    +    )
    +    output: queue.Queue[str] = queue.Queue()
    +    try:
    +        assert proc.stdin is not None
    +        assert proc.stdout is not None
    +        stdout = proc.stdout
    +        threading.Thread(
    +            target=lambda: output.put(stdout.readline()),
    +            daemon=True,
    +        ).start()
    +        proc.stdin.write(json.dumps({"id": 1, "command": "/tools"}) + "\n")
    +        proc.stdin.flush()
    +        try:
    +            line = output.get(timeout=10)
    +        except queue.Empty:
    +            pytest.fail("slash worker produced no /tools response within 10 seconds")
    +        response = json.loads(line)
    +        assert response["ok"] is True
    +        assert "mcp__profileprobe__hermes_61922_profile_probe" in response["output"]
    +    finally:
    +        proc.terminate()
    +        try:
    +            proc.wait(timeout=5)
    +        except subprocess.TimeoutExpired:
    +            proc.kill()
    +            proc.wait(timeout=5)

  • tui_gateway/slash_worker.py

    @@ -65,6 +65,27 @@ def _is_orphaned(original_ppid, parent_create_time, getppid=os.getppid) -> bool:
             return True
     
     
    +def _prepare_slash_worker_runtime() -> None:
    +    """Start bounded MCP discovery before HermesCLI snapshots tools.
    +
    +    Each slash_worker child is its own process — the parent ``hermes serve``
    +    discovery thread does not populate this registry (issue #61891).
    +    """
    +    import logging
    +
    +    from hermes_cli.mcp_startup import (
    +        start_background_mcp_discovery,
    +        wait_for_mcp_discovery,
    +    )
    +
    +    logger = logging.getLogger(__name__)
    +    start_background_mcp_discovery(
    +        logger=logger,
    +        thread_name="slash-worker-mcp-discovery",
    +    )
    +    wait_for_mcp_discovery()
    +
    +
     def _start_parent_death_watchdog(original_ppid, parent_create_time) -> None:
         def _loop():
             while not _is_orphaned(original_ppid, parent_create_time):
    @@ -129,6 +150,7 @@ def main():
         except psutil.Error:
             parent_create_time = 0.0
         _start_parent_death_watchdog(orig_ppid, parent_create_time)
    +    _prepare_slash_worker_runtime()
     
         with contextlib.redirect_stdout(io.StringIO()), contextlib.redirect_stderr(io.StringIO()):
             cli = HermesCLI(model=args.model or None, compact=True, resume=args.session_key, verbose=False)

• #122861 fix(mcp): resolve bare uv/uvx under GUI-style PATHs (#37589)

  merged to main

  files: hermes_platform/resolver/known_dirs.py, tests/tools/test_mcp_tool_issue_948.py, tools/mcp_tool_config.py