Codex Tools MCP Server

A minimal Model Context Protocol server implemented in Rust that exposes the update_plan and apply_patch tools used by the Codex GPT-5 model. It lets developers integrate these tools inside any MCP-aware client without running the Codex CLI.

Build & Run

Prerequisite: install Rust toolchain 1.90.0 or newer (edition 2024 support) before building, e.g. rustup toolchain install 1.90.0 and rustup override set 1.90.0 in this directory.

cargo build --release

The binary communicates over stdio using JSON-RPC 2.0. Launch it from an MCP-compatible host (for example, the MCP Inspector or any tool runner that can spawn stdio-based servers). Run ./target/release/codex-tools-mcp --help for command-line options (log level, version information).

Tool Schemas

• update_plan: matches the schema defined in codex-rs/core/src/plan_tool.rs (required plan array with step and status, optional explanation).
• apply_patch: matches the JSON variant defined in codex-rs/core/src/tool_apply_patch.rs (required input string containing the full patch payload).

The apply_patch tool reuses the official Codex codex-apply-patch crate to parse and apply patches, so file changes are applied exactly as in the CLI. The server streams the CLI-equivalent summary back in the MCP response. update_plan returns the acknowledgement "Plan updated".

Agents SDK Demo

For local testing without exposing an HTTP endpoint, use the OpenAI Agents SDK with the stdio MCP server:

pip install openai-agents
OPENAI_API_KEY=your_key python3 scripts/agents_demo.py

Set OPENAI_API_KEY (or export it beforehand) so the Agents SDK can authenticate with OpenAI. This runs the codex MCP binary via stdio and asks it to write hello world! into hello.txt in the working directory.