Market MCP Composer

A read-only market-data MCP service for ChatGPT/Codex, deployed on Cloudflare Workers and protected by Cloudflare Access. The first production provider is FinViz Elite Screener data.

Start here

• New deployment: QUICKSTART.md

• No Cloudflare/Zero Trust setup yet: CLOUDFLARE.md

• Connect or package for ChatGPT: CHATGPT.md and PLUGIN_UPLOAD.md

• FinViz setup: FINVIZ.md

Related MCP server: Yahoo Finance MCP Server

Architecture

ChatGPT / Codex
      |
      | OAuth + MCP
      v
Cloudflare Access
      |
      v
Cloudflare Worker (/mcp)
      |
      v
Provider adapter
      |
      v
FinViz Elite Screener export

The MCP server supplies authenticated live data. skills/ supplies reusable workflows that explain how to use the MCP tools consistently.

Current tools

finviz_lookup_ticker({ ticker }) — production read-only lookup of a ticker in the configured FinViz Elite Screener CSV export.

yahoo_lookup_ticker({ ticker }) — experimental read-only quote snapshot using Yahoo Finance's chart endpoint. This endpoint is not a documented Yahoo developer API and may change or throttle without notice; keep the provider disabled unless you intentionally choose to use it. See YAHOO_FINANCE.md.

Instance configuration

This repository contains no committed Cloudflare account or deployment instance values. Run npm run instance:init to create the Git-ignored config/instance.local.json; that file is the single source for non-secret per-account/per-deployment values. Secrets remain outside it. See CLOUDFLARE.md.

Production validation

After configuring config/instance.local.json and the Cloudflare administrative token, run:

npm run validate:all

This validation path is read-only. It checks Cloudflare Access, Managed OAuth/DCR, OAuth discovery, and the protected MCP endpoint without deploying or repairing anything.