Codex MCP Tool

What x51xxx/codex-mcp-tool MCP server does

The x51xxx/codex-mcp-tool MCP server exposes Codex CLI through MCP tools for coding assistance. It can analyze files referenced with @ syntax, continue conversations by session, apply sandboxed edits, produce structured change output, and run native repository reviews. The server supports model selection, reasoning controls, additional writable directories, web search, and local model providers through Ollama or LM Studio.

Its tool set covers both direct coding tasks and operational tasks. ask-codex handles general prompts, file analysis, model selection, sessions, and safety settings. batch-codex processes multiple atomic tasks sequentially or concurrently. review-changes invokes Codex’s review command, while do-act runs a task, checks the result with a shell command, and retries fixes when needed. Supporting tools provide health, version, help, session, skill, connection, and timeout information.

How it works

An MCP client starts the package as a local stdio process. The server then invokes the Codex CLI installed on the same machine. Codex must already be installed and authenticated, and the server requires Codex CLI 0.95.0 or newer. The health tool reports the detected CLI and session status; version reports Codex CLI, Node.js, platform, and package versions.

Session IDs allow multi-turn conversations with workspace isolation. A session can be reset when a fresh context is needed. Change mode returns structured OLD/NEW edits and may split large output into cached chunks; fetch-chunk retrieves later chunks. The CODEX_SESSION_TTL_MS and CODEX_MAX_SESSIONS settings control session lifetime and capacity.

The server can use the configured Codex model by omitting model, or override it for an individual request. Local execution can be selected with oss, localProvider: "ollama", or localProvider: "lmstudio". Ollama must be running locally with a model that supports tool calling.

Setup and configuration

Install and register the x51xxx/codex-mcp-tool MCP server with:

claude mcp add codex-cli -- npx -y @trishchuk/codex-mcp-tool

The package requires Node.js 18 or later. For manual MCP configuration, use npx as the command and pass -y and @trishchuk/codex-mcp-tool as arguments. Claude Desktop configuration paths differ by platform; the README identifies the macOS and Windows locations.

Graphical MCP clients may start with a restricted PATH. If the server cannot locate codex, set CODEX_CLI_PATH to the executable path, such as a Homebrew installation path, and use health to inspect resolution. Optional configuration includes CODEX_SESSION_TTL_MS and CODEX_MAX_SESSIONS.

Tools and capabilities

• Analyze files and directories with @ references.
• Continue work across prompts using session IDs and native resume support.
• Apply sandboxed edits and structured change-mode output.
• Run batch tasks for repetitive transformations and refactoring.
• Review current repository changes with Codex’s native review command.
• Execute, verify, and retry coding tasks through an act-check-fix loop.
• Discover skills under .agents/skills/ in the selected workspace.
• Generate ideas using SCAMPER, design-thinking, and lateral-thinking frameworks.
• Use web search when search: true is supplied.
• Connect to Ollama or LM Studio for local OSS models.

Limitations and notes

The x51xxx/codex-mcp-tool MCP server depends on the locally installed Codex CLI rather than providing Codex independently. Its README requires Codex CLI 0.95.0 or newer and recommends current releases. The available models and their reasoning limits are determined by the Codex CLI and configured provider.

Sandbox and full-auto options are compatibility aliases for workspace-write with approval disabled; they do not bypass the sandbox. Review, editing, and shell-verification behavior therefore depends on the selected Codex policies and the current workspace. Cross-platform support is documented for Windows, macOS, and Linux.