MCP-X

MCP-X is a single-file gateway designed to facilitate multi-client access to tools across servers using the Model Context Protocol (MCP). It addresses the challenge of securely sharing tools between multiple clients while maintaining precise, per-tool access control. The gateway enables administrators to decide which clients can see and interact with specific tools, using configurable wildcard patterns for fine-grained permissions.

The platform is implemented as a standalone Python file, allowing for straightforward deployment without the need for complex build processes or additional frameworks. Configuration is managed through a single TOML file, which defines clients, MCP servers, and access control policies. The system supports live configuration reloads, so changes to access permissions or client definitions take effect immediately without requiring a restart.

MCP-X provides both a REST API and support for the standard MCP protocol. The REST API allows for dynamic client registration, server registration, and management of access control policies via HTTP endpoints. Clients authenticate using JWT tokens, which can be dynamically generated (with a one-hour expiry) or statically defined in the configuration. The gateway also exposes a /mcp endpoint for tool listing and invocation, adhering to the MCP protocol standard.

This tool is suitable for environments where multiple users or systems need controlled access to distributed tools, such as development teams or organizations managing shared infrastructure. 0 license. Its development is attributed to contributors named stneng, littleround, and luke.