inspector

<div align="center"> <picture> <source media="(prefers-color-scheme: dark)" srcset="./client/public/mcp_jam_dark.png"> <source media="(prefers-color-scheme: light)" srcset="./client/public/mcp_jam_light.png"> <img width="250" alt="MCPJam Inspector V1 logo" src="./client/public/mcp_jam_light.png"> </picture> <br/> www.mcpjam.com [](https://www.npmjs.com/package/@mcpjam/inspector) [](https://opensource.org/licenses/Apache-2.0) [](https://discord.gg/JEnDtz8X6z) </div> MCPJam Inspector is the local development client for ChatGPT apps, MCP apps (Claude), and MCP servers. Build and test your apps with a full widget emulator, chat with any LLM, and inspect your server’s tools, resources, prompts, and OAuth flows. No more ngrok or ChatGPT subscription needed. MCPJam is the fastest way to iterate on any MCP project. ### 🚀 Quick Start Start up the MCPJam inspector: ```bash npx @mcpjam/inspector@latest ``` <img alt="MCPJam Inspector Demo" src="./docs/images/app-builder.png"> # Table of contents - [Installation Guides](#installation-guides) - [Key Features](#key-features) - [ChatGPT / MCP Apps Builder](#openai-apps--mcp-ui) - [OAuth Debugger](#oauth-debugger) - [LLM Playground](#llm-playground) - [Contributing](#contributing-) - [Links](#links-) - [Community](#community-) - [Shoutouts](#shoutouts-) - [License](#-license) # Installation Guides ### Requirements [](https://nodejs.org/) [](https://www.typescriptlang.org/) ## Install via NPM We recommend starting MCPJam inspector via `npx`: ```bash npx @mcpjam/inspector@latest ``` We also have a Mac and Windows desktop app: - [Install Mac](https://github.com/MCPJam/inspector/releases/latest/download/MCPJam.Inspector.dmg) - [Install Windows](https://github.com/MCPJam/inspector/releases/latest/download/MCPJam-Inspector-Setup.exe) # 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](https://www.mcpjam.com/blog/app-builder) | | MCP 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](https://www.mcpjam.com/blog/mcp-apps-preview) | | 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](https://www.mcpjam.com/blog/oauth-debugger) | | 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](https://www.mcpjam.com/blog/frontier-models) | | 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](https://www.mcpjam.com/blog/server-instructions) | ## ChatGPT Apps / MCP Apps Builder Develop [ChatGPT apps](https://developers.openai.com/apps-sdk/