Build a Portfolio Tracker

What you’ll build:

Fetch a wallet’s total value, 24h change, and chain breakdown
List token holdings with prices and handle pagination
Aggregate portfolio value across multiple wallets
Fetch balance charts to visualize value over time

=== WALLETS ===
Main (0xd8dA6B...): $12,017.49 (+2.33% 24h)
Trading (0x42b9df...): $3,450.21 (-0.85% 24h)

Combined total: $15,467.70

=== BY CHAIN ===
  ethereum: $9,214.01 (59.6%)
  base:     $3,573.03 (23.1%)
  arbitrum: $2,680.66 (17.3%)

=== TOP HOLDINGS (ALL WALLETS) ===
  ETH on ethereum (Main): 2.52 ($8,102.45)
  USDC on base (Trading): 2573.03 ($2,573.03)
  ARB on arbitrum (Main): 1450.00 ($1,230.45)
  ETH on base (Trading): 0.25 ($804.15)
  USDC on arbitrum (Main): 458.35 ($458.36)

=== MAIN - 1 MONTH CHART ===
  2/11/2026: $10,245.30
  2/18/2026: $11,102.88
  2/25/2026: $10,875.41
  3/4/2026:  $11,893.22
  3/11/2026: $12,017.49

Time: ~15 minutes

Prerequisites

A Zerion API key (get one here)
One or more wallet addresses to track
Node.js 18+ (for native fetch)

Steps

Next steps

Add DeFi positions to include staked and deposited assets in the totals
Track PnL and cost basis per wallet for tax reporting
Set up webhooks to update the dashboard in real time when any tracked wallet transacts

​Prerequisites

​Steps

​Next steps

Prerequisites

Steps

Next steps