Extract a key–value pair by index from JSON to fields in n8n

This workflow template takes a JSON object and a row index and returns exactly one key–value pair at that index. It is useful when you need to pick a single entry from structured JSON data and pass it to downstream nodes in n8n.

---

Who’s it for

• Developers working with API responses
• Makers building quick automations
• Analysts extracting specific values from JSON
• Anyone needing lightweight JSON manipulation without complex logic

---

How it works

1. Manual Trigger starts the workflow.
2. Set – Input JSON node contains:
   • myData: JSON object with key–value pairs
   • rowIndex: zero‑based index of the pair to extract
3. Code (Python) node iterates through the object and selects the key–value pair at the specified index.
4. Set – Key node outputs the extracted key.
5. Set – Value node outputs the extracted value.
6. The extracted key and value are available for further processing.

---

How to set up

1. Import the workflow into your n8n account.
2. Open the Input JSON node and replace the sample JSON:

{
  "myData": {
    "name": "Alice",
    "age": "30",
    "city": "Paris"
  },
  "rowIndex": "1"
}

3. Click Execute workflow.
4. Check the output of the Key and Value nodes.

---

Requirements

• n8n account (cloud or self‑hosted)
• Code node enabled (Python)
• Valid JSON object as input
• Zero‑based integer index (rowIndex)

---

How to customize

• Pick by key instead of index: Modify the Code node to directly reference a key name.
• Nested JSON support: Add logic to flatten or traverse nested objects.
• Output format: Return a combined object { key, value } instead of separate fields.
• Validation: Add guards for missing keys or invalid index values.

---

Add-ons

• Replace Manual Trigger with Webhook to accept live JSON payloads.
• Log extracted values into Google Sheets or a database.
• Add conditional routing based on extracted key or value.
• Chain with transformation workflows.

---

Use Case Examples

• Extract a specific field from an API response.
• Pick one answer from a form submission.
• Read configuration values dynamically.
• Control workflow routing using extracted JSON data.

---

Common troubleshooting

Issue	Possible Cause	Solution
Index out of range	Invalid rowIndex	Ensure index is within bounds
Wrong value extracted	JSON key order differs	Use key‑based selection
Empty output	myData is empty or invalid	Validate JSON input
Code node error	Python disabled	Enable Python or convert to JS
Unexpected type	Non‑string value	Cast value before use

---

Need Help?

If you need:

• Key‑based extraction
• Nested JSON handling
• Webhook‑based input
• Advanced validation or logging

Contact WeblineIndia for workflow customization and support.