MCPJam Inspector is a local testing tool for ChatGPT applications and MCP servers. It enables developers to build and debug directly on their machine without needing ngrok or a ChatGPT subscription. The suite includes a widget emulator, an LLM playground, and an OAuth inspector, providing real‑time feedback on tools, resources, prompts, and authorization flows. It speeds iteration, clarifies behavior, and offers detailed debugging for AI integrations and server endpoints.