How to Connect API to n8n?

If you want to connect an API to n8n or n8n VPS, it typically involves using the HTTP Request node within a workflow. The node allows interaction with external APIs by sending requests and receiving responses. Here’s a general guide on how to connect an API to n8n:

Step 1: Set Up n8n

• You can run on the local machine through npm, Docker, or user n8n.cloud (hosted version). 

For npm:

npm install n8n -g

n8n

• Open http://localhost:5678 in your browser.
• Create a new workflow. Click on “New Workflow” in the n8n dashboard.

Step 2: Choose a Trigger Node

• Add a Trigger (e.g., Webhook Trigger) to trigger the workflow.
• Sample: Webhook: Use Webhook when you wish to make a call to the workflow through an external API.

Step 3: Add an HTTP Request Node

• This is the most important step in order to have connections to any API.
• Click “+” button, then choose “HTTP Request node.”

Set the API connection:

• Operation: GET, POST, PUT, DELETE (based on API).
• URL: Type in the API endpoint (e.g. https:api.example.com/data).
• Headers: Add Headers (e.g., Authorization: Bearer <API_KEY)).
• Query Parameters: Append parameters (e.g.,?limit=10&page=1).
• Body Parameters (POST/PUT): Add the JSON data or form-data according to the API documentation.

Step 4: Test the Connection

• Click “Execute Node”, which will execute the API call.
• With a success, the rendering of the JSON response of the API will appear in the output panel.

Step 5: Process the Data

• Increase API data processing nodes:
• Set Node – Retrieve or change fields.
• Function Node – Custom JavaScript.
• Database/Spreadsheet Node Save API data in your storage.
• Other API Node -Send the result to a new API.

Step 6: Save and Activate Workflow

• Click “Save” to save your workflow.
• Toggle “Activate Workflow” to be automatically activated.

Example: An interface to OpenWeather API.

Add Webhook Trigger → to begin on hitting the URL.

Add HTTP Request Node with:

• Method: GET
• URL: https://api.openweathermap.org/data/2.5/weather
• Query Parameters:
• q=London
• appid=<YOUR_API_KEY>

Open the node to retrieve weather information.

Action or response to Slack, email or database.