Windows Codex App still fails to load native `computer-use-mcp` tool (`invalid type: map, expected variant identifier`)

[MAE5blog]

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

Windows app package: OpenAI.Codex_26.325.3894.0_x64__2p2nqsd0c76g0

The packaged Codex binary inside the app reports:

codex-cli 0.118.0-alpha.2

What subscription do you have?

No response

What platform is your computer?

Windows x64

What issue are you seeing?

Codex can see a native MCP server entry for computer-use, and the server itself starts successfully, but the MCP tool is silently unavailable to the model because Codex fails while converting the MCP tool schema into an OpenAI tool.

The exact error is:

Failed to convert "mcp__computer_use__computer" MCP tool to OpenAI tool: Error("invalid type: map, expected variant identifier", line: 0, column: 0)

As a result, the native computer-use-mcp tool cannot be used directly from Codex App on Windows, even though the underlying MCP server is healthy.

What steps can reproduce the bug?

1. On Windows, configure a local stdio MCP server in ~/.codex/config.toml like this:

[mcp_servers.computer-use]
command = 'C:\Program Files\nodejs\node.exe'
args = ['C:\Users\Administrator\.codex\skills\computer-use-bridge\.runtime\node_modules\computer-use-mcp\dist\main.js']
cwd = 'C:\Users\Administrator\.codex\skills\computer-use-bridge\.runtime'
startup_timeout_sec = 30.0

2. Verify the server is visible to Codex:

codex mcp list
codex mcp get computer-use

3. Run a real invocation through the Codex App packaged binary (I copied the app’s resources\codex.exe to a temp path to execute it directly).

4. Ask Codex to use the native MCP computer-use tool directly, for example:

Use the native MCP computer-use tool directly one time to read the current cursor position. Do not use shell commands or any bridge scripts.

5. Observe that the server starts and shows as ready, but the tool is unavailable because Codex logs the schema conversion error.

What is the expected behavior?

If the MCP server starts successfully and exposes a valid tool, Codex should load that tool and make it available to the model for direct use.

Additional information

Notes from local verification:

• The same machine can use the underlying computer-use-mcp server successfully through a shell bridge, so the server itself is not broken.
• computer-use-mcp version is 1.7.0.
• The server exposes a single tool named computer.
• The failure reproduces not only with the Windows app packaged binary (0.118.0-alpha.2), but also with an older separately installed npm CLI (0.115.0).
• Relevant log lines from the Windows app packaged binary run:

mcp: computer-use ready
Failed to convert "mcp__computer_use__computer" MCP tool to OpenAI tool: Error("invalid type: map, expected variant identifier", line: 0, column: 0)
Native MCP computer-use tool is unavailable in this session

For reference, computer-use-mcp tools/list returns an input schema like this:

{
  "type": "object",
  "properties": {
    "action": {
      "type": "string",
      "enum": [
        "key",
        "type",
        "mouse_move",
        "left_click",
        "left_click_drag",
        "right_click",
        "middle_click",
        "double_click",
        "scroll",
        "get_screenshot",
        "get_cursor_position"
      ]
    },
    "coordinate": {
      "type": "array",
      "items": [
        { "type": "number" },
        { "type": "number" }
      ]
    },
    "text": {
      "type": "string"
    }
  },
  "required": ["action"],
  "$schema": "http://json-schema.org/draft-07/schema#",
  "additionalProperties": false
}

This may be helpful if the failure is related to tuple-style items, MCP execution metadata, or another schema adaptation edge case.

[github-actions]

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

• Codex MCP schema translation converts array[string] tool params into string for memory_store.tags #15164

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[MAE5blog]

Thanks. I checked #15164 and it does look related at the MCP schema translation layer, but this issue appears to be a different failure mode rather than a pure duplicate.

My understanding of the difference is:

• Codex MCP schema translation converts array[string] tool params into string for memory_store.tags #15164: the tool loads, but Codex mis-translates an array[string] parameter into string, so the tool call is made with the wrong argument shape.
• This issue (Windows Codex App still fails to load native computer-use-mcp tool (invalid type: map, expected variant identifier) #16574): the computer-use-mcp tool does not become callable at all, because Codex fails during MCP tool -> OpenAI tool conversion with:
  • invalid type: map, expected variant identifier

In other words, in #15164 the tool is exposed but malformed; here the native MCP tool is excluded from use entirely.

I would not be surprised if both bugs live in the same schema adaptation/conversion subsystem, but from the user side they are distinct regressions:

• schema translated incorrectly but tool still callable
• schema conversion fails and tool never becomes available

If it helps, I’m happy to test any patched build or collect a narrower repro against the computer-use-mcp schema specifically.