Local Elgato MCP server does not become available in Codex on Windows

What version of the Codex App are you using (From “About Codex” dialog)?

26.825.41651

What subscription do you have?

Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

I configured the Elgato Stream Deck MCP server in Codex on Windows:
[mcp_servers.elgato_stream_deck]
enabled = true
command = "NPX"
args = ["--yes", "@elgato/mcp-server@0.1.5"]

[mcp_servers.elgato_stream_deck.env]
NODE_OPTIONS = "--use-system-ca"

The Stream Deck application is running, and its MCP integration is enabled. The “Enable MCP Deck” option is also enabled.
There is one test action configured in MCP Deck, but this action is not visible in Codex and is not exposed as an available MCP tool.

What has been verified:

• The physical Stream Deck device is connected and visible.
• Stream Deck version: 7.5.1.
• MCP Integration and “Enable MCP Deck” are enabled.
• One test action exists in MCP Deck.
• The test action is not visible in Codex.
• Node.js and npx are available from the system PATH.
• The TLS workaround using NODE_OPTIONS = "--use-system-ca" is present.
• Codex was restarted.
• A new Codex task was started afterward.
• Increasing the MCP startup timeout to 60 seconds did not help; that change was reverted.
• A fresh manual initialization test did not return an MCP response and eventually timed out.

Expected behavior:
Codex should complete the MCP handshake and expose the configured Stream Deck test action as an available tool.

Actual behavior:
The Elgato MCP server remains unavailable in Codex. The configured test action is not exposed, even after enabling MCP Deck, restarting Codex, starting a new task, and verifying the relevant configuration.

Could you help determine why Codex does not complete or retain the local stdio MCP client for the Elgato Stream Deck server?

What steps can reproduce the bug?

1. On Windows, install and run Stream Deck 7.5.1.
2. Enable the Stream Deck MCP integration and enable “MCP Deck”.
3. Add one test action in MCP Deck.
4. Configure the Elgato MCP server in Codex using:
   command = "NPX"
   args = ["--yes", "@elgato/mcp-server@0.1.5"]
5. Set NODE_OPTIONS = "--use-system-ca" for the MCP server.
6. Restart Codex and start a new task.
7. Check the available MCP tools or ask Codex to list the Stream Deck actions.

The bug occurs at step 7: the configured test action is not visible and no Stream Deck MCP tools are exposed.

What is the expected behavior?

Codex should successfully complete the MCP handshake with the local Elgato MCP server and expose the configured Stream Deck test action as an available MCP tool.

Additional information

The issue persists after restarting Codex and creating a new task. Stream Deck MCP Integration and “Enable MCP Deck” are enabled, and one test action has been added in MCP Deck but is not exposed by Codex.

The server configuration includes NODE_OPTIONS = "--use-system-ca" to address Windows certificate validation. A 60-second startup timeout was also tested and later reverted; it did not change the behavior.

The problem appears specific to Codex’s local stdio MCP client initialization or tool discovery. The physical Stream Deck device and the Stream Deck application are otherwise functioning normally.

Reproduce the issue on Windows with the Elgato configuration and the local NPX server. Start by tracing Codex’s local stdio MCP initialization and tool discovery; done means the handshake completes and the configured Stream Deck test action appears as an available MCP tool.