This week we’re releasing more tools to track OpenStreetMap metadata. Together with the American Red Cross, we’re launching OSM Metadata API, a tool to help enable analysis of OSM’s rich metadata at the user and comment level. By using hashtags in changeset comments such as #MissingMaps, API access can enable groups like the Red Cross to gain feedback from OSM deployments.

We’re building off our osm-meta-util work we released several weeks ago to store and index OSM metadata. We built the API on Elasticsearch and Node.js. Using Elasticsearch, we index and store metadata information such as changeset_id, user, created_at, bounding box, comment. You can filter these logs by hashtag and keyword as they come in real-time, as well as build a database of historical metadata logs.

We’re rolling out a sample API today with the code. You can access the endpoint here: https://api.developmentseed.org/osm.

You can use the full power of Apache Lucene Search to browse the data. For example, to browse for the #missingmaps hashtag between two dates:

`https://api.developmentseed.org/osm?search=created_at:[2015-04-08T00:00:00Z+TO+2015-04-09T00:00:00Z]+AND+comment:"missingmaps"`

In the past week, #missingmaps events have helped make 69,865 edits to OpenStreetMap in places like Haiti, Iraq, Zimbabwe, and Tanzania.

Check out the API guide for full endpoint documentation.

All code is available via a GitHub repository on OSM Lab. To get started quickly, you can deploy the API as a Heroku app. Try it out and contribute back to the OSM community.