n8n MCP Compliance Register + Discord Audit Logs

Keep your n8n MCP tool usage compliant—with an audit trail you can trust

This n8n automation workflow exposes a compliance register as an authenticated MCP server, complete with read tools for looking up records and viewing call history, plus a policy-guarded write tool that logs every attempt. It also posts a weekly compliance audit to Discord via webhook.

What this workflow does

• One-time setup: Run “Set Up Tables (run once)” to create three n8n Data Tables: tool policy, mcp_calls, and compliance register. It upserts an allow list and loads demo register records.
• Authenticated MCP server endpoint: The workflow exposes an MCP server protected with bearer authentication.
• Tool: lookup_record (read): Queries the compliance register table by record reference and returns up to 5 matching rows.
• Tool: read_call_log (read): Returns the most recent entries from mcp_calls (up to 25 rows).
• Tool: add_note (write, policy-guarded): Accepts a single-string request, checks the request against the mcp_tools allow list, verifies the referenced record exists, and enforces a per-day call cap using today’s allowed calls in mcp_calls. If permitted, it appends a dated note to the matching register row—otherwise it refuses.
• Audit logging: Every add_note attempt (allowed or refused) is recorded in mcp_calls and returned as plain-text to the MCP client.
• Weekly Discord audit: Every Monday at 08:00, it summarizes the last 7 days of calls and posts either an escalation or a quiet status message to Discord via webhook.

Use cases

• Compliance teams managing controlled access to records through MCP in n8n.
• SaaS operators needing an auditable trail of every MCP tool call and refusal.
• Automation engineers enforcing daily caps and tool allow lists for safer agent workflows.

Technical details

• Uses n8n nodes including if, set, code, discord, data table, and sticky note.
• Implements MCP tools: lookup_record, read_call_log, and add_note.
• Stores data in n8n Data Tables: tool policy, mcp_calls, and compliance register.