ChatGPT MCP and Apps: extensions you can try

A plugin extension that works in both the ChatGPT desktop app and the web, which the author calls fairly practical, running the whole software on Cloudflare Workers, D1 and R2 behind ChatGPT Sites.

Shares Appllama's MCP address and GitHub skills repo, plus a sample prompt using its design skills to recreate the ChatGPT chat interface.

A plugin developer asks publicly who is working on OpenAI MCP apps, saying they have a few low-cost suggestions that could meaningfully improve the experience for plugin developers.

The author open-sources their 13th project, showing how to build ChatGPT apps on MCP that feel close to native plugins, with a video.

The author says Codex computer use in the ChatGPT Mac app is a local MCP server that Claude Code can call directly, and shares a registration prompt plus an 8-task comparison.

Robinhood allows agents like ChatGPT and Claude to place trades through an MCP server, but it does not audit, control, or provide built-in risk guardrails for them.

A Japanese developer tried using ChatGPT Plugin Extensions to set a game's CPU algorithm in natural language; it wasn't finished in time but shows apps being operated inside ChatGPT.

An open-source MCP wrapping signal-cli with event support lets you interact with ChatGPT over Signal.

OpenAI has published an mcp-extensions repository, prompting the poster to remark on how fast the MCP ecosystem is evolving.

SelfManager is previewing an MCP server that will let users query their list data from Claude, ChatGPT, or Cursor, starting with a private beta before adding an API and Zapier/Make/n8n.

The developer turned the Magneta options tool into an MCP server that, once authorized, lets users ask ChatGPT or Claude Desktop for options views and position-opening suggestions on their holdings.

ChatGPT Sites is now usable: prompts generate hosted apps with optional custom domains, and MCP plugins can run on the same box, with HN already filling up with toy sites.