OpenAI Codex and Codex CLI Setup

Install WPF DevTools with 5-Minute Setup, then use the generated Codex registration command.

For normal Codex setup, use the installer path from 5-Minute Setup instead of portable ZIP extraction. Portable ZIP checks are only for reviewed local archives or offline validation.

Register

The installer writes:

<InstallRoot>\<arch>\client-registration\codex.txt

Run the command shown in that file from the shell where Codex CLI is available. It should point to:

<InstallRoot>\<arch>\current\bin\wpf-devtools-<arch>.exe

Verify

Set the reviewed target path and the scene-summary read gate before launching the client:

$target = 'C:\Path\To\YourApp.exe'
$env:WPFDEVTOOLS_MCP_ALLOWED_TARGETS = $target
$env:WPFDEVTOOLS_INJECTION_ALLOWED_TARGETS = $target
$env:WPFDEVTOOLS_MCP_ALLOW_SENSITIVE_READS = 'true'

Then ask Codex:

Use the WPF DevTools MCP server. Connect to the allowlisted WPF target and return get_ui_summary(depthMode: "semantic").

Deeper gated workflows

Keep the first Codex session narrow, then enable only the gate needed for the next approved tool:

  • WPFDEVTOOLS_MCP_ALLOW_SCREENSHOTS=true for element_screenshot.
  • WPFDEVTOOLS_MCP_ALLOW_VIEWMODEL_INSPECTION=true for get_viewmodel, command metadata, and ViewModel scopes in snapshots or batch_mutate.
  • WPFDEVTOOLS_MCP_ALLOW_DESTRUCTIVE_TOOLS=true for capture_state_snapshot, batch_mutate, interactions, event drain, and restore workflows.
  • For confirmed apply_ui_blueprint and apply_ui_project_integration writes, set WPFDEVTOOLS_MCP_ALLOW_DESTRUCTIVE_TOOLS=true, WPFDEVTOOLS_MCP_ALLOW_PROJECT_WRITES=true, and an exact WPFDEVTOOLS_MCP_ALLOWED_PROJECT_ROOTS match before launching a fresh MCP server process. Review the UI Composer apply and project-integration workflow first.

Before a mutation or ordered batch_mutate, take capture_state_snapshot, inspect get_state_diff, and restore when the workflow needs rollback.

Troubleshooting

  • Use the generated codex.txt command as the source of truth.
  • Re-register after changing architecture or install root.
  • If the target runs as administrator/elevated, launch the client from a matching elevated shell or prefer SDK-hosted diagnostics when policy blocks elevation.
  • Keep wrappers from writing to stdout because the server transport is STDIO.