Our Journal
Sharing our learnings from building MCPJam and the MCP community.
Deploy a MCP App (UI) on Cloudflare Workers
Learn how to deploy MCP Apps with rich user interfaces on Cloudflare Workers. Complete guide with template, configuration, and deployment instructions.
Build your first MCP App (UI)
Teams from MCP-UI, Anthropic, and OpenAI collaborated on a new standard to bring interactive UI to MCP clients. Learn how to build your first MCP App with real code examples.
MCP Apps (UI) support preview
MCPJam built the first working client prototype that supports MCP Apps. Learn about the collaboration between MCP-UI, Anthropic, and OpenAI to create the new MCP Apps standard.
Develop ChatGPT apps with full observability (ngrok)
MCPJam's ngrok tunneling feature enables you to observe all JSON-RPC messages sent between ChatGPT and your app via the ngrok tunnel.
MCP server instructions - give LLMs more context on your MCP server
Learn how to write effective MCP server instructions to improve tool ergonomics and help LLMs better understand how to use your MCP server.
Evaluating MCP servers - a quick guide
Learn how to measure and improve your MCP server's tool ergonomics using evals. Track accuracy, precision, and performance across multiple LLMs.
Track your MCP server's token use
Learn how to optimize your MCP server's token usage to prevent performance degradation, context loss, and hallucinations. Track token use in MCPJam Playground.
Open AI Apps SDK - Server Everything
A comprehensive reference implementation demonstrating all capabilities of the OpenAI Apps SDK.
MCPJam OAuth Debugger: Test every step of the MCP auth flow
Test every step of the MCP auth flow with MCPJam's OAuth debugger. Pinpoint issues in your auth implementation.
The MCP authentication checklist (November 2025 spec)
Step-by-step MCP OAuth guide. Covers the latest November 2025 spec with Client ID Metadata Documents (CIMD).
New MCP playground - Playground V2
MCPJam's new Playground V2 brings full support for MCP-UI and OpenAI Apps SDK, free frontier models, and advanced debugging tools for MCP server developers.
Writing MCP server unit tests
Learn how to write comprehensive unit tests for MCP servers using the MCPJam SDK and Jest. Test tools, prompts, and resources to ensure your MCP server is production-ready.
We added frontier models to our MCP playground for free
Access GPT-5, Claude 4.5, Gemini 2.5, and more frontier models inside MCPJam's LLM playground without your own API keys.
MCPClientManager - A Better Way to Build MCP Clients
Launching MCPClientManager, a powerful class to build real world MCP clients. Learn how to build fully capable clients.
Progressive disclosure might replace MCP (Claude Agent Skills)
We cover the tradeoffs of progressive disclosure and MCP, and the future of MCP with Claude Agent Skills.
Debug MCP servers at the JSON-RPC level
Learn how JSON-RPC powers MCP server communication, understand message types, and debug your MCP server effectively at the protocol level.
A look at OpenAI's Apps SDK under the hood
Dive into the architecture of OpenAI's Apps SDK, how it uses MCP servers and widgets, and the window.openai API.
Building with OpenAI Apps SDK
We built Apps SDK support in MCPJam's open source inspector to help you test your Apps SDK server, give you a head start.