CoinGecko is a cryptocurrency ranking website for tracking the activity of currencies and exchanges. In this guide, we’ll walk through how to pull cryptocurrency market data from the CoinGecko API directly into Google Sheets, using the API Connector add-on for Sheets. This is a free, open API so we won't need any API key.

• Part 1: Create your API Request URL
• Part 2: Enter values into API Connector
• Part 3: CoinGecko API Notes and Expansions

PART 1: CREATE YOUR COINGECKO API REQUEST URL

We’ll follow the CoinGecko API documentation to access the current price of ETH (Ethereum).

• API root: https://api.coingecko.com
• Endpoint: /api/v3/coins/markets
• Query String: ?vs_currency={currency}&ids={coin ID}
  Query String Example: ?vs_currency=usd&ids=ethereum

Putting it together, we get the full API Request URL:

https://api.coingecko.com/api/v3/coins/markets?vs_currency=usd&ids=ethereum

PART 2: ENTER YOUR VALUES INTO API CONNECTOR

We can now enter all our values into API Connector and import Coinbase API data into Google Sheets.

1. Open up Google Sheets and click Add-ons > API Connector > Create New API Request.
2. In the Create Request interface, enter the Request URL we just created.
   
3. Leave the Headers section empty. This API is open and public, so we don't need any authentication.
4. Create a new tab. You can call it whatever you like, but here we'll call it 'CoinGecko-ETH'. While still in that tab, click 'Set' to use that tab as your data destination.
5. Name your request. Again we'll call it 'CoinGecko-ETH'
6. Click Run and a moment later you’ll see the latest exchange rate data for Ethereum to USD appear in your Google Sheet:
   

PART 3: COINGECKO API + GOOGLE SHEETS NOTES AND EXPANSIONS

1. Experiment with endpoints and query strings as described in the documentation to see other types of currency and crypto data from the API. For example, you can try the following URLs, one at a time:
   https://api.coingecko.com/api/v3/simple/price?ids=ethereum&vs_currencies=usd
https://api.coingecko.com/api/v3/coins/list
https://api.coingecko.com/api/v3/coins/bitcoin/tickers
https://api.coingecko.com/api/v3/exchanges
2. For a more dynamic, ticker-like experience in Sheets, check out the API Connector custom function IMPORTAPI().

IMPORTANT SECURITY NOTE

Anyone with Owner or Edit access to your Google Sheet can view all the information you've saved within API Connector, including API keys and other credentials. Treat these keys as passwords and limit access to your sheet accordingly.