Endpoint

• URL: http://127.0.0.1:7341/mcp
• Auth: Authorization: Bearer <token> (copy from Configure)
• Browser Origin requests are rejected
• Transport: stateless Streamable HTTP with JSON POSTs; GET /mcp returns a keep-alive SSE stream

Example client config

{
  "mcpServers": {
    "sumeru": {
      "url": "http://127.0.0.1:7341/mcp",
      "headers": {
        "Authorization": "Bearer <token>"
      }
    }
  }
}

Gateway tools

Sumeru exposes exactly three MCP tools:

Tool	Inputs	Outputs
list_mcps	none	configured MCP ids, names, transports, enabled flags
list_mcp_tools	mcp_id	upstream tool names, descriptions, schemas
execute_mcp_tool	mcp_id, tool_name, arguments?	upstream CallToolResult

Lifecycle

• Upstream clients connect lazily on first list_mcp_tools / execute_mcp_tool
• Connections are reused until Sumeru quits, the MCP is edited/deleted, or the transport closes
• Tool execution is never auto-retried after an ambiguous failure

Storage and security

• Config: app config dir /sumeru/servers.json
• Secrets: OS keychain service sumeru
• Funnel binds only to 127.0.0.1
• Stdio commands are argv-based (no shell strings)
• Upstream tool metadata/output is untrusted data