What are time-series, tables and custom APIs? How do I know if the data feed I'm using is in time-series or tables format, or if it uses a custom API?
Quandl has optimized the vast majority of data feeds for one of two different formats: time-series and tables. You can learn more about these formats here.
Our API documentation outlines the API calls, Python and R commands, and Excel formulas to use for data in time-series format vs. tables format. Please ensure that you are using the correct syntax in your API call, or the correct commands, for the format of the data you're trying access.
As for custom APIs, each data feed that uses a custom API comes with documentation that explains how to make API calls for that feed. For example, the ORATS Smoothed Options Market Quotes data feed uses a custom API and its Documentation explains how to make custom API calls. Please note that data feeds using a custom API may only be downloaded via the custom API routes described in their documentation. These data feeds may not be downloaded through Quandl's Python Package, R Package or Excel Add-In.
It is important to know the format of the data feed you're trying to access because this will affect the structure of the API call or command that you use to download data from a particular data feed.
The product page for each data feed indicates if that data feed is a time-series or table, or if it uses the custom API.
Here is the product page for the End of Day US Stock Prices data feed. As you'll see on the right-hand panel, this data feed is in time-series format:
Here is the product page for the Sharadar Equity Prices data feed. As you'll see on the right-hand panel, this data feed is in tables format:
Here is the product page for the ORATS Smoothed Options Market Quotes data feed. As you'll see on the right-hand panel, this data feed uses a custom API: