Posuer: MCP Manager and Interposer

What is Posuer?

Posuer is a Model Context Protocol (MCP) manager and interposer that consolidates multiple MCP servers into a single connection point for LLM clients like Claude Desktop. It aggregates capabilities, manages server configurations, and intelligently routes requests to the appropriate backend servers.

How to use Posuer?

Build Posuer from source using Go (1.23+), then run the binary with a YAML configuration file. Use the -config flag to specify a custom config path and -watch to enable dynamic configuration reloading. For Claude Desktop, add Posuer as an MCP server in claude_desktop_config.json with the command /path/to/posuer and arguments ["-watch"].

Key features of Posuer

• Dynamic server management with hot reloading
• Aggregates capabilities from multiple servers
• Routes requests to appropriate backends
• Supports stdio and SSE transport types
• Runs servers in Docker containers automatically
• Enables fine-grained capability filtering

Use cases of Posuer

• Consolidate multiple MCP servers into one endpoint for Claude Desktop
• Dynamically add or remove servers without restarting the client
• Isolate MCP servers using Docker containers for security
• Rotate API keys or update endpoints on-the-fly with config watching

FAQ from Posuer

What dependencies are required to run Posuer?

Go 1.23 or higher and access to MCP servers (e.g., filesystem, weather, search).

How does dynamic configuration reloading work?

Use the -watch flag to enable file watching; when the configuration file is modified, Posuer automatically loads and applies the changes without restarting.

Can I run MCP servers in containers?

Yes, you can specify a container image in the configuration, or Posuer will auto-detect containers for npx and uvx commands using node:alpine and uv:alpine images respectively.

How do I connect Posuer to Claude Desktop?

Add an entry in Claude Desktop's claude_desktop_config.json with the command pointing to the Posuer binary and the -watch argument if desired.

What configuration formats are supported for capability filtering?

You can use boolean (enable/disable all), a list of tool names, or a map that distinguishes between tools, prompts, templates, and resources.