Build Autonomous AI Workflows with n8n: A Technical Introduction to Agentic Automation

By Yangming Li

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📌 Table of Contents

1. Why talk about agents?

Most automation tutorials stick to workflows—a linear series of steps where every output path is pre-wired. Useful, but rigid.

By contrast, an agentic system pairs a Large Language Model (LLM) with a toolbox of actions; at run time the model decides which tool(s) to invoke and how to combine the results. Think of:

Workflow Agent
Post-purchase email ✔️ Customer-support LLM that can open tickets, pull orders, and issue refunds 🛠️

n8n (pronounced "n-eight-n") is one of the first open-source platforms to treat both paradigms as first-class citizens. Its Advanced AI Agent node drops an LLM into any workflow and lets you bolt on tools à-la-carte.

2. n8n essentials at a glance

Concept What it is Why it matters for agents
Workspace Cloud or self-hosted project root Holds your credentials, executions, and multiple workflows
Node A single step in a workflow Five families: Triggers, Actions, Utilities, Code, Advanced AI
Execution A run of a workflow/agent Every chat message or API hit shows up here for debugging
Credentials API keys, OAuth tokens, etc. Centralised; reuse the same OpenAI key in many agents

The five node families

  • Triggers · Start the flow (cron, webhook, chat, etc.).
  • Actions · Concrete API calls (Gmail, Telegram, Airtable…).
  • Utilities · Branching, data transforms, storage.
  • Code · JavaScript, HTTP Request, custom Webhook.
  • Advanced AI · Chat Model and AI Agent nodes—where the magic lives.

3. Walk-through: a Home-Inventory Agent

We'll replicate the demo from the video: a chat-based agent that searches and updates an Airtable stock list.

Prerequisites

  • n8n Cloud workspace (or self-hosted ≥ v1.50)
  • OpenAI (or Anthropic, Groq, etc.) API key
  • Airtable base with fields: Item Name, Current Qty, Order Threshold

3.1 Create the skeleton

Trigger → On Chat Message
Set to "Public" so anyone with the URL can chat.

Advanced AI → AI Agent
Think of this node as the agent's "brain".

Chat Model inside the agent

Provider: OpenAI
Model: gpt-4o
Memory → Window Buffer
Store last 5 turns so the agent remembers context ("4, 5, 6 …").

3.2 Add the first tool – Search Airtable

Inside the AI Agent node → Tools → ➕

Setting Value
Type Airtable
Operation Search
Credential Personal access token with scopes schema.read, data.records:read
Tool description Searches my "Home Inventory" Airtable base for items and quantities.

Now the LLM can decide, "User asked 'What's out of stock?'—I'll run the Search tool."

3.3 Add the second tool – Update records

Add another Airtable tool:

Setting Value
Operation Update
Tool description Updates item quantities in the Home Inventory base.

Inside the field mapper, use fromAI expressions so the model injects parameters dynamically:

id: {{ fromAI("record_id",
              "The Airtable record ID of the item to update") }}

Current Qty: {{ fromAI("new_qty",
                       "New quantity for this item",
                       "number") }}

When you say, "I just bought two tubes of toothpaste—update my inventory," the agent:

  1. Searches the base to find the record_id for toothpaste.
  2. Calls the Update tool with new_qty = previous + 2.

3.4 Test the loop

Chat window →

User: Is anything out of stock?
Agent: Butter has Current Qty = 0.
User: I picked up 2 butters, please update.
Agent: Updated Butter → Current Qty = 2.

No hard-coded paths; the agent chose both tools on its own.

4. Scaling up with sub-agents

Large projects rarely fit in one canvas. n8n lets you:

  • Convert a workflow into a callable tool (Trigger → When Called by Another Workflow).
  • Nest agents – A "front-door" agent can route intents to specialised sub-agents:
Customer Agent
 ├── Inventory Agent  (Airtable tools)
 ├── Order Agent      (Stripe, Shopify)
 └── FAQ Agent        (Vector search, RAG)

Each sub-agent has its own memory, prompt, and credentials—yet the parent agent uses a single Call Workflow tool to orchestrate them.

5. Best practices & tips

Tip Why
Write rich tool descriptions. The LLM's planner relies on them to pick the right action.
Start with small context windows. Shorter memories are cheaper and reduce hallucinations.
Guard mutate operations. Add an if-statement or human approval before updates that spend money or hit prod systems.
Log executions. n8n's Executions tab captures every agent decision—vital for prompt tuning.
Version your prompts. Store long system prompts in an n8n Static Data node or pull from Git.

6. Where to go next

  • n8n Docs – Advanced AI
    Deep-dive on fromAI, vector stores, and function calling.
  • AI Foundations Community (featured in the video)
    25-module course + weekly calls on LLM ops.
  • Source-control your workflows
    n8n supports JSON export—check it into Git to diff prompt changes.

Conclusion

Agents turn automation upside-down: instead of us defining the path, we define capabilities and let the model think. n8n's new AI Agent node, paired with a vast catalog of Triggers and Actions, makes it one of the fastest ways to prototype and ship production-grade agentic systems—no heavyweight orchestration layer required.

Spin up a workspace, wire in a chat model, and give your LLM a toolbox. Your first autonomous workflow is only a few nodes away. Happy building!