# Bug Report: Computer Use MCP tools return "unsupported call"

Open 💬 2 comments Opened May 29, 2026 by hermanhsu-rgb

Description

Computer Use plugin MCP tools (mcp__computer_use__list_apps, mcp__computer_use__get_app_state, etc.) consistently return "unsupported call" despite the MCP server processes running correctly.

Steps to Reproduce

  1. Enable Computer Use plugin in Codex App
  2. Grant Accessibility permissions to Codex App and Codex Computer Use
  3. Restart Codex App
  4. Attempt to call any mcp__computer_use__* tool
  5. Tool returns "unsupported call"

Expected Behavior

MCP tools should route calls to the SkyComputerUseClient MCP server and return results.

Actual Behavior

All Computer Use MCP tool calls return "unsupported call" immediately.

Environment

  • Codex App version: 26.527.30818 (also reproduced on 26.519.81530)
  • macOS: Sequoia 15.x
  • Hardware: Apple Silicon (M-series)

Investigation

MCP server processes are confirmed running (SkyComputerUseService + SkyComputerUseClient). Direct MCP protocol test succeeds:

echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test","version":"1.0"}}}' | SkyComputerUseClient mcp
Returns valid JSON-RPC response. .mcp.json configuration is correct. Codex App logs show plugin loaded but no MCP connection establishment. Browser plugin works correctly in same environment.

Additional Notes
Issue persists across app restarts, plugin reinstalls, and accessibility permission resets
Both ~/.codex/computer-use/ and ~/.codex/plugins/cache/ paths tested

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