Quick Start
Start up the MCPJam inspector with a bash commandStart MCPJam Inspector
Start testing your MCP servers immediately
Key features
| Capability | Description |
|---|---|
| ChatGPT Apps SDK | Local development for ChatGPT Apps SDK support. Full support for the windows.openai API: widgetState, callTool, structuredContent, sendFollowUpMessage, displayMode, CSP, and more. No more ngrok or ChatGPT subscription needed. Read more |
| MCP ext-apps (Claude) | Full local development for MCP Apps (SEP-1865). Support for all JSON-RPC message types, such as tools/call, ui/initialize, ui/message, ui/open-link, and more. Read more |
| OAuth Debugger | Debug your MCP server’s OAuth implementation at every step. Visually inspect every network message. Supports all protocol versions (03-26, 06-18, and 11-25). Support for client pre-registration, DCR, and CIMD. Read more |
| LLM playground | Chat with your MCP server against any LLM in the playground. We provide frontier models such as GPT-5 and Claude Sonnet for free, or bring your own API key. Playground supports ChatGPT apps and MCP Apps. Read more |
| MCP server debugging | Connect to and test any MCP server local or remote. Manually invoke MCP tools, resources, resource templates, and elicitation flows. View all JSON-RPC logs. Support for all features from the official MCP inspector. |
| Server info | View server icons, version, capabilities, instructions, and ChatGPT widget metadata exposed by the server. Read more |