n8n Tutorial for Beginners - Build Your First Free AI Agent

About this video

A presenter playing ‘David’ from David’s Donut Den builds a free, no-code AI agent in n8n to chase overdue invoices. He defines an agent by three traits — reasoning toward a goal rather than following explicit steps, tool access to act (email, post, pay), and memory across tasks — and contrasts it with n8n’s 14-day cloud trial (up to 1,000 executions) versus free self-hosting via Docker Desktop (create an n8n_data volume, enable WSL on Windows). In the editor he configures the sample agent with Google Gemini as the chat model (via an AI Studio API key credential), choosing Gemini 2.5 Flash-Lite Preview because, he says, the free plan allows 15 requests per minute and 1,000 per day, plus Simple Memory set to store the last five messages. He adds QuickBooks Online (Get Many invoices, with the overdue filter left for the model to define) and a Send Email tool via Gmail SMTP using an app password, disabling the n8n attribution. He uses ChatGPT to draft the agent prompt from role, task, tools, and outputs — polite under seven days overdue, firmer after, one email per customer, JSON output — and inserts the current date with JavaScript. After test runs send two reminders, he rebuilds it as human-in-the-loop: a structured output parser returns customer name, email, subject and body, a weekly schedule trigger replaces chat, Split Out and Loop Over Items feed each draft to Discord for approve/disapprove, and an IF branch sends email only when approved is true. A sponsor segment notes QuickBooks Online itself has built-in AI payment reminders.

Key takeaways

• n8n can be self-hosted for free with Docker Desktop instead of using the 14-day / 1,000-execution cloud trial; setup requires creating an n8n_data volume and WSL on Windows
• A working agent needs three configured parts: a chat model, memory, and tools — the tutorial uses free Gemini (creator cites 15 requests/minute and 1,000/day) and Simple Memory holding the last five messages
• Let the model define tool parameters (e.g., the overdue-invoice filter, email recipient, subject, body) and name tools clearly (‘Get Invoices’, ‘Send Payment Reminder’) so the agent uses them correctly
• Prompt via a role/task/tools/outputs template generated in ChatGPT, inject today’s date with JavaScript, and iterate on the prompt when test runs fail
• For real use add human-in-the-loop: structured output parser, weekly schedule trigger, Split Out + Loop, Discord approve/disapprove, and an IF-approved branch before any email is sent

Episode details: published July 29, 2025 · 23:10 long. Summary written by Self Growth Videos from the episode itself. Business results and any income figures mentioned are Kevin Stratvert’s own claims, shared for education — they are not typical or guaranteed.

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