# Darly

> Darly serves public lidar elevation data through one API host (https://api.darly.io): a STAC catalog for finding and downloading source elevation data, and an Elevation API for point lookups, path sampling, and raster (GeoTIFF) extracts. The STAC catalog is browsable anonymously; elevation endpoints require a free API key sent as an X-API-Key header.

## Docs

- [Overview](https://darly.io/docs/md/index): One API for public lidar elevation data — a STAC catalog plus an Elevation API, with a single key and one set of quotas.
- [Quickstart](https://darly.io/docs/md/quickstart): Create an API key and make your first elevation lookup and STAC search in under five minutes.
- [Authentication](https://darly.io/docs/md/authentication): API keys, the three ways to send them, anonymous access, and how quotas attach to your account.
- [Elevation API: points](https://darly.io/docs/md/elevation): Point lookups, batch lookups, and path sampling — parameters, response shapes, and source-selection behavior.
- [Elevation API: raster extracts](https://darly.io/docs/md/raster): Clip a DEM as a cloud-optimized GeoTIFF — elevation or hillshade, with output size or resolution, projection, and provenance options.
- [STAC catalog API](https://darly.io/docs/md/stac): Browse and search the full catalog with any STAC client — collections, item search, pagination, and asset access.
- [COG downloads](https://darly.io/docs/md/downloads): Whole-file downloads of Darly-hosted source COGs on paid plans — how /dl links work and how they're metered.
- [Rate limits, quotas & errors](https://darly.io/docs/md/limits): Per-plan monthly quotas, per-minute burst limits, rate-limit headers, and every error shape the API returns.
- [Coverage & datasets](https://darly.io/docs/md/coverage): Every collection Darly serves — region, resolution, products, license — plus source ranking and vertical-datum caveats.

## Reference

- [OpenAPI specification](https://darly.io/openapi.json): OpenAPI 3.1 description of every public endpoint, with parameter schemas and error shapes
- [Full documentation](https://darly.io/llms-full.txt): every docs page concatenated into one Markdown file