AI Agents
Module 10Lesson 3

Lesson 3. n8n Interface: Nodes, Connections, Execution

Hands-on: n8n

Lesson 3. n8n Interface: Nodes, Connections, Execution#

Goal: understand the n8n interface and how to build workflows.

Main Interface Elements#

1. Canvas

The main workspace where you build workflows from nodes and connections.

2. Node Panel (Left)

List of all available nodes: triggers, actions, logic, data, AI.

3. Node Settings Panel (Right)

When you click a node, its settings open on the right (parameters, credentials, testing).

4. "Execute Workflow" Button

Manually runs the workflow (for testing).

5. "Save" Button

Saves the workflow.

6. Execution History (Executions)

Shows workflow run history (successful, failed).

What Is a Node#

Node — a block that performs one action:

  • reads data from a service (e.g., "read rows from Google Sheets")

  • sends data to a service (e.g., "send message to Telegram")

  • processes data (e.g., "transform JSON", "filter rows")

  • makes HTTP requests (universal node for any API)

Node Types#

1. Trigger Nodes

Nodes that start a workflow when an event occurs:

  • Webhook — fires when an HTTP request hits a URL

  • Cron — fires on a schedule (every day at 9:00, every hour)

  • Manual Trigger — fires manually ("Execute Workflow" button)

  • Service triggers (e.g., "Google Sheets Trigger" — new row in a sheet)

2. Action Nodes

Nodes that perform actions with data:

  • Google Sheets — read/write data in a spreadsheet

  • Telegram — send a message

  • HTTP Request — send a request to any API

  • OpenAI — generate text via ChatGPT

3. Logic Nodes

Nodes for conditions and branching:

  • IF — perform different actions depending on a condition

  • Switch — choose a branch based on a value

  • Merge — combine data from different branches

4. Data Nodes

Nodes for working with data:

  • Set — set or change field values

  • Code — write JavaScript code to process data

  • Item Lists — work with lists (filter, sort, group)

How to Connect Nodes#

Nodes are connected by arrows (connections). An arrow shows where data flows.

Example:



Manual Trigger → HTTP Request → Telegram

What happens:

  1. Manual Trigger fires (you press "Execute Workflow")

  2. HTTP Request makes an API request (e.g., fetches exchange rate)

  3. Telegram sends a message with the result

How to Execute Workflows#

Method 1: Manually

  • press the "Execute Workflow" button (used for testing)

Method 2: By Trigger

  • if the workflow starts with a trigger (Webhook, Cron, service trigger), it will run automatically

Method 3: Via API

  • you can invoke the workflow via API (useful for integration with other systems)