Manage portfolio assets via webhook with Google Sheets and real-time totals

Description

Webhook-Based Portfolio Manager (n8n + Google Sheets + API)

This workflow turns your n8n instance into a portfolio management API using a webhook and Google Sheets. You can add, update or delete assets via a simple POST request and it automatically calculates your total portfolio value in real-time.

Quick Implementation Steps

Import the workflow into your n8n account
Connect your Google Sheets OAuth2 credentials
Ensure your sheet has columns: Asset, Amount, Price, Value
Activate the workflow
Send a POST request to the webhook with:
{
"asset": "BTC",
"amount": 2,
"price": 30000,
"action": "add"
}

What This Workflow Does

This workflow acts as a REST-like API for managing investment portfolios using n8n. It receives data via a webhook, processes it and performs operations on a Google Sheet.

It supports three core operations:

Add** a new asset
Update** an existing asset
Delete** an asset

Each request is validated to ensure correctness before execution. The workflow also prevents duplicate entries and invalid operations.

After performing any action, it fetches the full portfolio, calculates the total portfolio value and returns a structured JSON response with updated data.

Who It's For

Developers building financial dashboards or APIs
Traders tracking portfolios via automation
No-code/low-code users using n8n + Google Sheets
Anyone wanting a lightweight portfolio backend without a database

Requirements

To use this workflow, you need:

n8n account (self-hosted or cloud)
Google account with access to Google Sheets
Configured Google Sheets OAuth2 credentials in n8n
A Google Sheet with STRICT required columns:
Asset
Amount
Price
Value
Basic knowledge of API requests (POST)

How It Works & Setup Instructions

1. Webhook Trigger

Node: Portfolio Webhook Trigger
Accepts POST requests
Entry point for all operations

2. Normalize Input Data

Converts:
asset → uppercase
amount, price → numbers
Calculates:
value = amount × price

3. Validate Input

Node: Validate Amount & Price
Ensures:
amount ≥ 0
price ≥ 0
value ≥ 0

Error Path: Invalid Amount/Price

If validation fails:

{
"error": "value of amount or price is not correct it should be in positive number"
}

4. Route by Action

Node: Route by Action (Add/Update/Delete)
Supported values:
add
update
delete

Error Path: Missing Action

{
"error": "action field is required, add key in json called action and in value add, update or delete."
}

Error Path: Invalid Action Value

{
"error": "action should contains only one of these three values ['add', 'update', 'delete']."
}

ADD Operation

Flow:

Check Asset Exists (Add)
Asset Exists? (Add)

Error Path: Asset Already Exists

{
"error": "Asset: BTC is already in your portfolio"
}

Success:

Node: Add New Asset
Appends row to Google Sheets

UPDATE Operation

Flow:

Update Existing Asset
Asset Found?

Error Path: Asset Not Found (Update)

{
"error": "Asset: BTC is not found in your portfolio"
}

Success:

Updates matching row using Asset column

DELETE Operation

Flow:

Check Asset Exists (Delete)
Asset Found? (Delete)

Error Path: Asset Not Found (Delete)

{
"error": "Asset: BTC is not found in your portfolio"
}

Success:

Node: Delete Asset Row
Removes row using row index

Portfolio Calculation

After any operation:

Combine All Operation Outputs
Fetch Full Portfolio
Calculate Portfolio Value

Logic:

Iterates through all rows
Calculates:
totalPortfolioValue = sum of all values

Final Response

Returns:

{
"message": "Asset: BTC is added, now your total portfolio value is: $60000",
"Assets": [...]
}

How To Customize Nodes

Webhook Path**
Change endpoint in Portfolio Webhook Trigger
Sheet Name / ID**
Modify in all Google Sheets nodes
Validation Rules**
Update conditions in Validate Amount & Price
Response Format**
Customize JSON in Final Response to User
Matching Logic**
Change matching column (default: Asset)

Add-ons (Enhancements)

You can extend this workflow with:

Email notifications after transactions
Real-time price API integration
AI-based investment insights
Dashboard using tools like Retool or Power BI
Slack/Telegram alerts
Transaction history logging

Use Case Examples

Personal crypto portfolio tracker
Stock portfolio API backend
Admin panel for investment tracking
Automated trading journal
SaaS MVP for portfolio management

And many more depending on your use case.

Troubleshooting Guide

| Issue | Possible Cause | Solution |
| -------------------------- | -------------------------- | ----------------------------- |
| Webhook not working | Workflow not active | Activate workflow in n8n |
| Invalid amount/price error | Negative or missing values | Ensure positive numbers |
| Asset not updating | Asset not found in sheet | Check exact asset name |
| Duplicate asset error | Asset already exists | Use update instead of add |
| Delete not working | Row not found | Verify asset exists |
| Empty response | Merge or calculation issue | Check node connections |

Need Help?

If you need help with:

Setting up this workflow
Customizing features
Adding integrations (AI, APIs, dashboards)
Building similar automation systems

Reach out to n8n workflow developers at WeblineIndia for expert assistance.

We specialize in building scalable n8n workflows, automation systems and custom integrations tailored to your business needs.