EIA Open Data API

The EIA Open Data API v2 provides programmatic access to free U.S. energy time-series data through a hierarchical route structure organized by energy category. An API key is required (free registration) and is passed as a URL query parameter on every request. Responses include rich metadata for navigating child routes, facets, frequencies, and available data columns. The API supports JSON (default) and XML output, with up to 5,000 rows per request for JSON and 300 rows for XML.