---
layout: default
title: API - Query data programmatically
nav_order: 10
has_children: true
---


# API overview

[Data Commons](https://datacommons.org){: target="_blank"} aggregates data from many
different [data sources](https://datacommons.org/datasets){: target="_blank"} into a single
database. Data Commons is based on the data model used by
[schema.org](https://schema.org){: target="_blank"}; for more information, see [Key concepts](/data_model.html).

The Data Commons APIs allow developers to programmatically access the data in Data Commons, using the following technologies:

* A [REST API](/api/rest/v2) that can be used on the command line as well as in any language with an HTTP library.
* A [Python](/api/python/v2) client library that wraps the REST APIs and includes support for [Pandas](https://pandas.pydata.org/){: target="_blank}.

The endpoints can be roughly grouped into three categories:

-   **Statistical data**: Given a set of statistical variables, dates and entities, get observations.

-   **Graph exploration**: Given a set of nodes, explore the graph around those nodes.

-   **Resolution to DCIDs**: Given a set of place nodes identified by other means, get their Data Commons IDs.

In addition, Data Commons provides additional tools for accessing its data that call the REST APIs under the hood:

- [Google Sheets](sheets/index.md): provides several custom functions that populate spreadsheets with data from the Data Commons knowledge graph
- [Web Components](web_components/index.md): provides JavaScript APIs and HTML templates that allow you to embed Data Commons data and visualizations into web pages

Finally, an R client library is available from a third-party provider, [Tidy Intelligence](https://www.tidy-intelligence.com/). Learn more at https://github.com/tidy-intelligence/r-datacommons/.

{: #get-key}
## API keys

A key is required for APIs to authenticate and authorize requests, as follows:
- All REST [V2](rest/v2/index.md) APIs. These requests are served by endpoints at `api.datacommons.org`.
- [Python and Pandas V2](python/v2/index.md) APIs, also served by `api.datacommons.org`.
- Data Commons MCP server requests. These are served by `api.datacommons.org/mcp`. 
- All requests coming from a custom Data Commons instance. These are also served by `api.datacommons.org`.
- Data Commons MCP server requests. These are served by `api.datacommons.org/mcp`.
- Data Commons NL API requests (used by the [DataGemma](https://ai.google.devgit/gemma/docs/datagemma){: target="_blank"} tool). These are served by endpoints at `nl.datacommons.org`.

A key is currently not required for the following, although this may change in the future:
- Google Sheets
- Web Components

### Obtain an API key

Data Commons API keys are managed by a self-service portal. To obtain an API key, go to [https://apikeys.datacommons.org](https://apikeys.datacommons.org){: target="_blank"}  and request a key for the hostname(s) listed above. Enable each of the APIs you want; you can share a single key for all of them.

To use the key in requests, see the relevant documentation:
- [REST V2 APIs](/api/rest/v2/index.html#authentication).
- [Python/Pandas V2 APIs](api/python/v2/index.html#authentication).
- For NL APIs in DataGemma, see the Colab notebooks in [https://github.com/datacommonsorg/llm-tools/tree/main/notebooks](https://github.com/datacommonsorg/llm-tools/tree/main/notebooks){: target="_blank"}