English-Version/Open-Access-Monitor/API-of-the-OAM.md

-In addition to the web interface, the open access monitor offers an open REST API, which is available at  https://api.open-access-monitor.de/. 
+In addition to the web interface, the open access monitor offers an open REST API, which is available at [REST-API](https://open-access-monitor.de/api). All public data of the monitor can be queried.
 
+# Data query
+This end point is required for data query:
+
+`/data/{database}`
+
+So far only "public" can be used as database`. The query is passed by `query` parameter. The following [MongoDB-Commands](https://www.mongodb.com/docs/manual/reference/command/) are supported by the API:
+* [find](https://www.mongodb.com/docs/manual/reference/command/find/)
+* [aggregate](https://www.mongodb.com/docs/manual/reference/command/aggregate/)
+* [count](https://www.mongodb.com/docs/manual/reference/command/count/)
+* [distinct](https://www.mongodb.com/docs/manual/reference/command/distinct/)
+* [getMore](https://www.mongodb.com/docs/manual/reference/command/getMore/)
+* [mapReduce](https://www.mongodb.com/docs/manual/reference/command/mapReduce/)
+* [listCollections](https://www.mongodb.com/docs/manual/reference/command/listCollections/)
+
+All API answers are formatted according to the answers of the MongoDB.
+The entities are described [here](https://jugit.fz-juelich.de/synoa/oam-dokumentation/-/wikis/English%20Version/Open%20Access%20Monitor/Database%20Schema). Possible collections for queries: 
+* Publications
+* PublicationCosts
+* Journals
+* Publishers
+* Organisations
+The previous week’s data is stored in additional collections with the suffix `_old`, which are updated every Sunday. With this endpoint and without a query parameter a list of all collections can be obtained.
+
+The OA Categories are encoded as numbers as shown in this table: [OA Categories]( https://jugit.fz-juelich.de/synoa/oam-dokumentation/-/wikis/English%20Version/Open%20Access%20Monitor/OA%20Categories)
+
+# Examples
+* Query of all Gold-OA publications from 2020 \
+[https://open-access-monitor.de/api/Data/`public`?query=`{find:"Publications", filter:{year: 2018, oa_color: 7}}`](https://open-access-monitor.de/api/Data/public?query=%7Bfind%3A%22Publications%22%2C%20filter%3A%7Byear%3A%202018%2C%20oa_color%3A%207%7D%7D)
+* Journals from the DFG application list \
+[https://open-access-monitor.de/api/Data/`public`?query=`{find:"Journals", filter:{flags: "DFG-Anträge"}}`](https://open-access-monitor.de/api/Data/public?query=%7Bfind%3A%22Journals%22%2C%20filter%3A%7Bflags%3A%20%22DFG-Antr%C3%A4ge%22%7D%7D)
+* Publication count per OA Categorie \
+[https://open-access-monitor.de/api/Data/`public`?query=`{aggregate:"Publications", cursor:{}, pipeline:[{$group:{_id:"$oa_color", sum:{$sum: 1}}}]}`](https://open-access-monitor.de/api/Data/public?query=%7Baggregate%3A%22Publications%22%2C%20cursor%3A%7B%7D%2C%20pipeline%3A%5B%7B%24group%3A%7B_id%3A%22%24oa_color%22%2C%20sum%3A%7B%24sum%3A%201%7D%7D%7D%5D%7D)
+
+# Swagger
+
+We offer [Swagger](https://open-access-monitor.de/api/swagger), because all endpoints can be seen and tried there.
+
+# Terms of use
 We have a fair use policy for the API. Although there are no fixed quotas, we reserve the right to take appropriate measures should we notice above-average utilization. If you are planning very large queries, please consult us in advance.
-The technical documentation of the possible endpoints can be found at https://api.open-access-monitor.de/swagger/. 
+