Crypto

CoinGecko uses full IDs, not ticker symbols. Common IDs:

Find IDs at: curl -s "https://api.coingecko.com/api/v3/search?query=NAME" → use coins[0].id

Output Parsing

Single price — extract value from JSON:

curl -s "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin&vs_currencies=usd" | python3 -c "import sys,json; print(json.load(sys.stdin)['bitcoin']['usd'])"

Multi-coin with 24h change:

curl -s "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin,ethereum&vs_currencies=usd&include_24hr_change=true" | python3 -c "
import sys,json
data = json.load(sys.stdin)
for coin, vals in data.items():
    price = vals['usd']
    change = vals.get('usd_24h_change', 0)
    arrow = '▲' if change > 0 else '▼'
    print(f'{coin}: \${price:,.2f}  {arrow}{abs(change):.2f}%')
"

Full market response (includes market cap, volume, ATH):

curl -s "https://api.coingecko.com/api/v3/coins/markets?vs_currency=usd&ids=bitcoin&per_page=1" | python3 -c "
import sys,json
d = json.load(sys.stdin)[0]
print(f'Price:      \${d[\"current_price\"]:,.2f}')
print(f'24h Change: {d[\"price_change_percentage_24h\"]:.2f}%')
print(f'Market Cap: \${d[\"market_cap\"]:,.0f}')
print(f'Volume:     \${d[\"total_volume\"]:,.0f}')
print(f'ATH:        \${d[\"ath\"]:,.2f}')
"

Common Queries

Bitcoin current price

curl -s "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin&vs_currencies=usd"

Top 5 coins by market cap

curl -s "https://api.coingecko.com/api/v3/coins/markets?vs_currency=usd&order=market_cap_desc&per_page=5&page=1&sparkline=false"

Specific coin with custom fields

curl -s "https://api.coingecko.com/api/v3/coins/bitcoin?localization=false&tickers=false&community_data=false&developer_data=false"

Rate Limit Handling

Free tier: 50 calls/minute. Cache results when possible — exchange rates don't change every second. If rate-limited, wait 60 seconds before retrying.

Error Handling