Codex Ask User

Codex Ask User is a local Model Context Protocol (MCP) server that gives Codex a native, structured way to clarify requirements before it commits to a plan or implementation.

It uses MCP elicitation so Codex CLI and Codex desktop can display native controls for:

• single-choice questions;
• multiple-choice questions;
• free-text and custom answers;
• recommended choices that are labeled and preselected;
• a Discuss with Codex first path that returns to chat before asking again;
• session-scoped automatic selection of recommended answers.

Requirements

• Node.js 20 or newer
• Codex CLI or Codex desktop with MCP elicitation enabled

Build and test

npm install
npm test

The build produces a self-contained MCP server at plugins/ask-user/dist/server.js.

Install as a Codex MCP server

Build the project, then register the generated server using its absolute path:

codex mcp add ask-user -- node /absolute/path/to/codex-ask-user/plugins/ask-user/dist/server.js

Start a new Codex CLI session or desktop task after registration. The server exposes these tools:

• ask_user presents one to three single-choice, multiple-choice, or free-text questions.
• set_question_preferences enables, disables, or reports automatic use of recommended answers for the current MCP session.

The repository also contains an installable Codex plugin bundle in plugins/ask-user. Its .mcp.json uses ${PLUGIN_ROOT}, so the bundle remains relocatable.

Codex approval policy

MCP elicitation must be allowed by the active Codex approval policy. To keep other prompt categories non-interactive while allowing questions, use:

approval_policy = { granular = { sandbox_approval = false, rules = false, mcp_elicitations = true, request_permissions = false, skill_approval = false } }

In Codex desktop, the task's permission selector can override config.toml. Full access uses an approval policy that rejects MCP elicitations without displaying the question. Select the custom configuration and start a new task after changing the policy.

If ask_user immediately returns declined without visible UI, check the task's active approval policy before treating the result as a user decision.

Example

An agent can call ask_user with a recommended option and an open-ended alternative:

{
  "questions": [
    {
      "id": "database",
      "header": "Database",
      "question": "Which database should back the first release?",
      "kind": "single",
      "options": [
        {
          "label": "PostgreSQL",
          "description": "A strong default for production workloads.",
          "recommended": true
        },
        {
          "label": "SQLite",
          "description": "Simpler deployment for a local-first application."
        }
      ],
      "allow_other": true,
      "allow_discussion": true
    }
  ]
}

Selecting Always use recommended choices automatically resolves later questions that have recommendations during the current MCP session. Questions without recommendations are still shown. Ask Codex to stop auto-selecting recommendations to restore the default behavior.

Development

npm run check
npm run build
npm test

• src/server.ts contains the MCP server and tool implementation.
• tests/server.test.js tests elicitation flows through an in-memory MCP client.
• scripts/build.mjs bundles the server with esbuild.
• plugins/ask-user contains the Codex plugin manifest and MCP configuration.

Author

blhsing