fix(tools): resolve uv/uvx MCP commands under GUI-style PATHs (fixes #37589)

[Morad37]

What does this PR do?

Fixes bare command: uv / command: uvx MCP server configs from Hermes Desktop on macOS. The Hermes Desktop app inherits a minimal LaunchAgent PATH (/usr/bin:/bin:/usr/sbin:/sbin) that doesn't include ~/.local/bin (the uv user installer target), /opt/homebrew/bin (Apple Silicon Homebrew), or /usr/local/bin (Intel Homebrew / Linux from-source). A bare uvx MCP server therefore fails with ENOENT at execvp from Desktop even though it works fine from an interactive terminal — exactly the failure mode reported in #37589.

Changes

• tools/mcp_tool.py (_resolve_stdio_command)
  • Added uv and uvx to the bare-command candidate allowlist (was only npx/npm/node before).
  • Added $HERMES_HOME/bin/<cmd> as a candidate for managed uv/uvx (from refactor(uv): single managed-uv path, delete fts5 installer escalation #37660). Managed uv is preferred over ~/.local/bin, Homebrew, etc. so MCP servers use the same uv as the CLI update path.
  • Added a new /opt/homebrew/bin/<cmd> candidate for the Apple Silicon Homebrew case (brew install uv). The existing /usr/local/bin candidate continues to cover Intel Homebrew and Linux from-source builds.
  • Candidate ordering: Hermes-bundled Node → managed uv ($HERMES_HOME/bin) → ~/.local/bin → /opt/homebrew/bin → /usr/local/bin.
• tests/tools/test_mcp_tool_issue_948.py
  • New test: test_resolve_stdio_command_finds_uvx_in_user_local_bin — covers the dominant install location for uv on Apple Silicon / Ubuntu.
  • New test: test_resolve_stdio_command_uvx_unchanged_when_already_on_path — ensures shutil.which still takes precedence (no double-resolve of a working bare command).
  • New test: test_resolve_stdio_command_skips_unknown_commands — negative test that catches the inverse regression of someone widening the allowlist so far that a bare command: my-tool gets rewritten to a coincidentally-named file at /opt/homebrew/bin/my-tool.
  • New test: test_resolve_stdio_command_prefers_managed_uv — verifies that $HERMES_HOME/bin/uv wins over a stale ~/.local/bin/uv (cross-reference with refactor(uv): single managed-uv path, delete fts5 installer escalation #37660).
  • The 4 existing npx tests continue to pass unchanged.

How to test

1. ~/.hermes/hermes-agent/venv/bin/python -m pytest tests/tools/test_mcp_tool_issue_948.py -q --timeout=60 — 9/9 pass.
2. ~/.hermes/hermes-agent/venv/bin/python -m pytest tests/tools/ -q --timeout=60 -k "mcp" — no regressions in the broader MCP test surface.

Notes

• The CLI / TUI paths were never affected (they inherit a full terminal PATH). This is a Desktop/launchd-only fix.
• Sandbox / docker config can still pass an explicit env.PATH and the resolver will still honour it via _prepend_path. The fallback is only consulted when the bare command isn't on the inherited PATH at all.
• No change to behaviour for any command outside the npx/npm/node/uv/uvx allowlist — random bare commands like python or my-tool are left alone (the new negative test pins this).
• The managed-uv candidate ($HERMES_HOME/bin) was added in coordination with refactor(uv): single managed-uv path, delete fts5 installer escalation #37660, which introduced managed uv at that location. Without it, MCP servers on Desktop would fall back to a stale ~/.local/bin or brew-managed uv instead of the hermes-managed one.

Closes #37589

[teknium1]

Thanks for isolating the remaining launchd-PATH half of #37589. The current-main resolver still only falls back for npx/npm/node at tools/mcp_tool.py:591, so extending the allowlist is a valid fix direction.

Problems

• The PR body says managed uv/uvx at $HERMES_HOME/bin is preferred, but the actual candidate list in PR head f4ce36cd4724 (tools/mcp_tool.py:423-454) has no $HERMES_HOME/bin/<cmd> entry. This leaves a managed-only uv unavailable under the filtered Desktop PATH, despite Hermes defining that managed location in hermes_cli/managed_uv.py:1-50.

Suggested changes

• Add the managed-bin candidate before ~/.local/bin, and add a regression test that it wins over a stale local install. Please also exercise the new /opt/homebrew/bin candidate.

Automated hermes-sweeper review.

[teknium1]

Please add $HERMES_HOME/bin/<cmd> to this fallback list before ~/.local/bin. The PR description promises managed uv preference, and hermes_cli/managed_uv.py:1-50 defines $HERMES_HOME/bin/uv as Hermes’s authoritative managed location; it is absent from this PR head’s candidates.

[zhangpk688]

hope to solve asap,when config mcp, it is difficult.