Model Context Protocol

Flux starts configured MCP servers as local subprocesses and communicates through newline-delimited JSON-RPC over stdin and stdout.

#Configure a server

Add mcpServers to ~/.flux/config.json or ./.flux/config.json:

{
  "mcpServers": {
    "everything": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-everything"],
      "env": {
        "LOG_LEVEL": "warn"
      }
    }
  }
}

Each server supports a command, optional argument list, and optional environment overrides. Restart Flux after changing server configuration.

#Exposed capabilities

• Tools are registered in the main tool pool with their server name in the description.
• Resources are summarized in model context and read on demand through mcp_read_resource.
• Prompts become slash commands. Flux requests the rendered prompt from the owning server and submits its messages to the conversation.

If one server fails to start, Flux continues without it. Run /debug to see connected server names and counts for discovered resources and prompts.

Flux currently documents stdio subprocess configuration; it does not expose an HTTP/SSE server configuration shape.