Plain Automation via Rube MCP

Automate Plain operations through Composio's Plain toolkit via Rube MCP.

Toolkit docs: composio.dev/toolkits/plain

Prerequisites

• Rube MCP must be connected (RUBE_SEARCH_TOOLS available)
• Active Plain connection via RUBE_MANAGE_CONNECTIONS with toolkit plain
• Always call RUBE_SEARCH_TOOLS first to get current tool schemas

Setup

Get Rube MCP: Add https://rube.app/mcp as an MCP server in your client configuration. No API keys needed — just add the endpoint and it works.

1. Verify Rube MCP is available by confirming RUBE_SEARCH_TOOLS responds
2. Call RUBE_MANAGE_CONNECTIONS with toolkit plain
3. If connection is not ACTIVE, follow the returned auth link to complete setup
4. Confirm connection status shows ACTIVE before running any workflows

Tool Discovery

Always discover available tools before executing workflows:

RUBE_SEARCH_TOOLS
queries: [{use_case: "Plain operations", known_fields: ""}]
session: {generate_id: true}

This returns available tool slugs, input schemas, recommended execution plans, and known pitfalls.

Core Workflow Pattern

Step 1: Discover Available Tools

RUBE_SEARCH_TOOLS
queries: [{use_case: "your specific Plain task"}]
session: {id: "existing_session_id"}

Step 2: Check Connection

RUBE_MANAGE_CONNECTIONS
toolkits: ["plain"]
session_id: "your_session_id"

Step 3: Execute Tools

RUBE_MULTI_EXECUTE_TOOL
tools: [{
  tool_slug: "TOOL_SLUG_FROM_SEARCH",
  arguments: {/* schema-compliant args from search results */}
}]
memory: {}
session_id: "your_session_id"

Known Pitfalls

• Always search first: Tool schemas change. Never hardcode tool slugs or arguments without calling RUBE_SEARCH_TOOLS
• Check connection: Verify RUBE_MANAGE_CONNECTIONS shows ACTIVE status before executing tools
• Schema compliance: Use exact field names and types from the search results
• Memory parameter: Always include memory in RUBE_MULTI_EXECUTE_TOOL calls, even if empty ({})
• Session reuse: Reuse session IDs within a workflow. Generate new ones for new workflows
• Pagination: Check responses for pagination tokens and continue fetching until complete

Quick Reference

Operation	Approach
Find tools	RUBE_SEARCH_TOOLS with Plain-specific use case
Connect	RUBE_MANAGE_CONNECTIONS with toolkit plain
Execute	RUBE_MULTI_EXECUTE_TOOL with discovered tool slugs
Bulk ops	RUBE_REMOTE_WORKBENCH with run_composio_tool()
Full schema	RUBE_GET_TOOL_SCHEMAS for tools with schemaRef

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