Build your own CUSTOM API MCP server

by Jimleuk ✓ · 19,130 views · created 2025-04-21 · HR, AI RAG

What this workflow does

This AI workflow has 20 nodes and runs when an MCP client calls one of its tools (plus 1 other trigger). Along the way it connects Google Sheets. It also calls api.paycaptain.com over HTTP.

How it runs

Trigger: When an MCP client calls one of its tools (plus 1 other trigger).

1. Log Call (Google Sheets): append
2. Operation (Switch): routes items into 3 branches
3. Get Employees (HTTP Request): calls api.paycaptain.com
4. Get Employees (HTTP Request): calls api.paycaptain.com
5. Valid Fields Only (Edit Fields (Set)): sets 1 field: values
6. Filter: keeps only the items that match a condition
7. Filter: keeps only the items that match a condition
8. Has Valid Request? (If): checks a condition and branches into true / false
9. Strip Sensitive Fields (Edit Fields (Set)): sets 20 fields: company, hrEmployeeId, payrollCode…
10. Strip Sensitive Fields (Edit Fields (Set)): sets 20 fields: company, hrEmployeeId, payrollCode…

…plus 5 more steps. See the full node list below.

Services it uses

Google Sheets

HTTP calls to: api.paycaptain.com

Before you upgrade to n8n 3.0

Nodes used (10)

• Execute Workflow Triggern8n-nodes-base.executeWorkflowTrigger
• Switchn8n-nodes-base.switch
• MCP Server Trigger@n8n/n8n-nodes-langchain.mcpTrigger
• Call n8n Workflow Tool@n8n/n8n-nodes-langchain.toolWorkflow
• HTTP Requestn8n-nodes-base.httpRequest
• Google Sheetsn8n-nodes-base.googleSheets
• Filtern8n-nodes-base.filter
• Aggregaten8n-nodes-base.aggregate
• Edit Fields (Set)n8n-nodes-base.set
• Ifn8n-nodes-base.if

From the author

This n8n demonstrates how any organisation can quickly and easily build and offer MCP servers to their customers or internal staff to improve productivity. This MCP example uses PayCaptain.com as an example and shows how to create an MCP server which can…

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