Evm Token Decimals

If you've ever shipped a balance display that was off by a factor of a million because you assumed USDC had 18 decimals everywhere, this prevents that. It walks you through runtime decimal queries, chain-aware caching, and decimal-safe math in Python, TypeScript, and Solidity. The examples are practical: fetching balances with web3.py, normalizing to WAD in contracts, handling non-standard tokens that revert on decimals(). It's focused on the silent bugs that don't throw errors but wreck dashboards and trading bots. Worth a look if you're building anything that touches ERC-20s across multiple chains or needs reliable fiat conversions.

skills.sh installs: 3.4K
GitHub stars: 229.1K
last updated: Jul 14, 2026

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Install

$ npx -y skills add affaan-m/everything-claude-code --skill evm-token-decimals --agent claude-code

Installs into .claude/skills of the current project.

Files

EVM Token Decimals

Silent decimal mismatches are one of the easiest ways to ship balances or USD values that are off by orders of magnitude without throwing an error.

When to Use

Reading ERC-20 balances in Python, TypeScript, or Solidity
Calculating fiat values from on-chain balances
Comparing token amounts across multiple EVM chains
Handling bridged assets
Building portfolio trackers, bots, or aggregators

How It Works

Never assume stablecoins use the same decimals everywhere. Query decimals() at runtime, cache by (chain_id, token_address), and use decimal-safe math for value calculations.

Examples

Query decimals at runtime

from decimal import Decimal
from web3 import Web3

ERC20_ABI = [
    {"name": "decimals", "type": "function", "inputs": [],
     "outputs": [{"type": "uint8"}], "stateMutability": "view"},
    {"name": "balanceOf", "type": "function",
     "inputs": [{"name": "account", "type": "address"}],
     "outputs": [{"type": "uint256"}], "stateMutability": "view"},
]

SKILL.md on GitHub