Codex availability check fails on Windows even when codex is on PATH

[harihara-ai]

When the MCP server is started with PATH containing the directory with codex.cmd (e.g. %APPDATA%\npm), and the server is the direct child of the process that has that PATH, the Codex availability check still fails with "Codex CLI not found." The subprocess used for the check (asyncio.create_subprocess_shell("codex --version")) does not appear to inherit the process environment on Windows. Please pass env=os.environ (or equivalent) when creating that subprocess so the child sees the same PATH.

[harihara-ai]

Root cause: subprocess env not passed on Windows

The “Codex CLI not found” / “Cursor Agent unavailable” behavior when the CLI works in your terminal is caused by subprocesses being started without an explicit environment. On Windows, the child then does not reliably see the same PATH as the Roundtable process (e.g. when Roundtable is started by the orchestrator with a modified PATH).

1. roundtable_mcp_server — availability_checker.py

File: .../roundtable_mcp_server/availability_checker.py

All four CLI checks use asyncio.create_subprocess_shell without env:

• Lines 47–51 — Codex: create_subprocess_shell("codex --help", stdout=..., stderr=...)
• Lines 79–83 — Claude: create_subprocess_shell("claude --help", ...)
• Lines 111–114 — Cursor: create_subprocess_shell("cursor --help", ...) (note: Cursor adapter uses cursor-agent -h, this file uses cursor)
• Lines 143–146 — Gemini: create_subprocess_shell("gemini --help", ...)

So the shell child that runs codex --help (etc.) inherits the default environment and may not see the parent’s PATH.

Fix: Pass the current environment into the subprocess, e.g.:

proc = await asyncio.create_subprocess_shell(
    "codex --help",
    stdout=asyncio.subprocess.PIPE,
    stderr=asyncio.subprocess.PIPE,
    env=os.environ.copy(),
)

Same for the other three checks.

---

2. claudable_helper — Codex adapter

File: .../claudable_helper/cli/adapters/codex_cli.py

• Lines 34–38 — check_availability():
  create_subprocess_shell("codex --version", ...) with no env=.
  So the “is Codex installed?” check can fail on Windows even when Codex is on the parent’s PATH.

• Lines 155–161 — execute_with_streaming():
  create_subprocess_exec(*cmd, ..., cwd=project_repo_path) with no env=.
  So the actual codex run may also not see the same PATH as the Roundtable process.

Fix: For both calls, pass env=os.environ.copy() (and keep any other needed env vars). That way the Codex process sees the same PATH (and other env) as the Roundtable server.

---

3. claudable_helper — Cursor adapter

File: .../claudable_helper/cli/adapters/cursor_agent.py

• Lines 31–35 — check_availability():
  create_subprocess_shell("cursor-agent -h", ...) with no env=.
  So “Cursor Agent unavailable” can happen when cursor-agent (or agent) is on the parent’s PATH but not in the child’s.

• Lines 268–274 — execute_with_streaming():
  create_subprocess_exec(*cmd, ..., cwd=project_repo_path) with no env=.
  Same issue for the real Cursor run.

Fix: Add env=os.environ.copy() to both calls so the Cursor subprocess sees the same environment (including PATH) as the Roundtable process.

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4. Other adapters (Claude, Gemini)

The same pattern appears in:

• claudable_helper/cli/adapters/claude_code.py — create_subprocess_shell for availability (no env).
• claudable_helper/cli/adapters/gemini_cli.py — availability check without env; execution uses an env dict in some code paths but not necessarily in the initial spawn.

Fixing all CLI adapters and the Roundtable availability checker the same way (explicit env=os.environ.copy() or equivalent) makes behavior consistent and fixes “not found” on Windows when the orchestrator (or IDE) has set PATH for the Roundtable process.

---

Summary

Location	Call	Issue
roundtable_mcp_server/availability_checker.py	4× create_subprocess_shell("... --help", ...)	No env → child may not see parent PATH on Windows
claudable_helper/.../codex_cli.py	create_subprocess_shell("codex --version") + create_subprocess_exec(*codex_cmd)	No env on either call
claudable_helper/.../cursor_agent.py	create_subprocess_shell("cursor-agent -h") + create_subprocess_exec(*cursor_cmd)	No env on either call
claudable_helper/.../claude_code.py	availability shell call	No env
claudable_helper/.../gemini_cli.py	availability shell call	No env

Root cause: Subprocesses are started without passing the current process environment. On Windows, inheritance of PATH to these children is unreliable, so the CLIs are reported as “not found” or “unavailable” even when they work in the same machine’s shell.

Recommended fix (for Roundtable/claudable_helper maintainers): For every create_subprocess_shell and create_subprocess_exec that runs a CLI (codex, cursor-agent, claude, gemini), pass env=os.environ.copy() (or a dict that includes the same PATH and other required variables) so the child process explicitly gets the same environment as the MCP server process.