Automation library · Data collection

Route MCP tool calls with Claude

Started by another system calling it, and works across Email and Google Sheets. It hands the judgement calls to Claude. 19 steps, 1 branch, 1 loop or waits: a working afternoon to understand properly.

MediumCalls a model: Claude

Download free
19 stepsMedium: a working afternoon
1Branch: places the flow splits
1Loop or waits
2Services it connects to

The flow

Starts it 2Model 2Logic 9Service 6

The steps in the order they run, from what starts it.

  1. 1Receive MCP Tool RequestWebhookStarts it
  2. 2Claude AI ModelLm Chat AnthropicModel
  3. 3Validate Auth and MCP SchemaCodeLogic
  4. 4Claude AI Intent and Safety VerificationAgentModel
  5. 5Lookup Tool in RegistryGoogle SheetsService
  6. 6Parse Intent Verification ResultCodeLogic
  7. 7Resolve Tool Config and PermissionsCodeLogic
  8. 8Check Rate Limit and QuotaGoogle SheetsService
  9. 9Wait For ResultWaitLogic
  10. 10Enforce Rate Limit and Build Execution ContextCodeLogic
  11. 11Dry Run or Live Execution?IfLogic
  12. 12Execute Backend API CallHttp RequestService
  13. 13Build Dry Run ResponseCodeLogic
  14. 14Normalize Backend Response to MCP SchemaCodeLogic
  15. 15Send Security Alert on High Risk CallsEmail SendService
  16. 16Write Immutable Audit LogGoogle SheetsService
  17. 17Update Rate Limit Usage LogGoogle SheetsService
  18. 18Build Final MCP Tool ResultCodeLogic
  19. 19Return MCP Tool Result to CallerRespond To WebhookStarts it

How it's built

Starts on
Another system calling it
Steps
19, with 1 branch, 1 loop or waits
Size
Medium: a working afternoon
Connects to
Email, Google Sheets
Model
Claude

Questions

What does it need to run?

An n8n account, plus your own Email and Google Sheets accounts, and a key for Claude. You connect your own accounts after importing it; none are included.

What starts it?

It starts on another system calling it.

Does it use AI?

Yes. It calls Claude. Model calls are billed by the provider, not by n8n.

How long does it take to set up?

Plan an afternoon. 19 steps is enough that you should read each one before running it.

How do I import it?

Copy the workflow, open a new workflow in n8n and paste. The steps appear on the canvas, ready for your own accounts.

Before you run it

Nothing here has been tested by us. It is somebody's working automation, read and described from its own steps. Treat the connections it wants as a list of accounts it will touch, and read the 19 steps before you point it at anything that matters.