|

Overview

ARIA is a personal Slack-based AI assistant built in n8n. I can write a natural request in Macedonian, and ARIA coordinates Outlook contacts, calendar availability, and email drafting through specialized MCP agents.

A typical request is: write to a contact about today's lunch, apologize in a friendly tone, check my next free calendar slot, include that date, and draft the email in Romanian. ARIA prepares the message, shows the preview, and only sends after approval.

The public material explains the architecture and selected code patterns. It does not publish the original workflow JSON, Slack channel IDs, user IDs, credential names, n8n cloud URLs, or private mailbox data.

The challenge

Daily admin work often crosses several tools: contacts, calendar, email, files, and language translation. Doing that manually means switching context several times for one simple request.

The challenge was to make the assistant useful without making it unsafe. It needed to understand informal instructions, use the correct tools, draft in the requested language, and still keep the user in control before anything is sent or changed.

My role

I built the n8n workflow architecture, the Slack entry point, the smart processor, the routing logic, the central ARIA agent, the specialized MCP workflows, and the response cleanup layer.

I also designed the safer interaction pattern: preview first, approval second, execution last.

Workflow structure

Core modules

Technical decisions

Tech stack

Proof / Evidence

This case study is based on a private n8n system. The public proof focuses on architecture, design decisions, and sanitized snippets. Original workflow exports, credential IDs, Slack IDs, n8n cloud endpoints, contact data, and mailbox data are not published.

Live system

Click to enlarge

Public code & documentation

Code excerpt: approval gate before sending

The important safety rule is simple: ARIA may draft an email, but sending requires explicit user approval from the preview step.

// Approval gate pattern for email actions in a Slack assistant.
// The assistant can draft the message, but sending is blocked until
// the user confirms the preview.

function buildEmailPreview({ recipient, subject, body, targetLanguage }) {
  return {
    type: "email_preview",
    status: "awaiting_approval",
    recipient,
    subject,
    body,
    targetLanguage,
    actions: ["approve_send", "edit_draft", "cancel"],
  };
}

function canSendEmail(state) {
  return state.type === "email_preview" && state.status === "approved";
}

if (!canSendEmail(currentState)) {
  return {
    action: "show_preview",
    message: "Please review and approve the email before sending.",
  };
}

return {
  action: "send_email",
  tool: "Email Agent MCP",
  payload: currentState,
};

Full sanitized example in snippets/approval-gate.js. The repository also documents the smart processor, router, MCP agent map, and response cleanup layer.