  The continued advancement of science depends on shared and reproducible data.
In the field of computational materials science and rational materials design
this entails the construction of large open databases of materials properties.
To this end, an Application Program Interface (API) following REST principles
is introduced for the AFLOWLIB.org materials data repositories consortium.
AUIDs (Aflowlib Unique IDentifier) and AURLs (Aflowlib Uniform Resource
locator) are assigned to the database resources according to a well-defined
protocol described herein, which enables the client to access, through
appropriate queries, the desired data for post-processing. This introduces a
new level of openness into the AFLOWLIB repository, allowing the community to
construct high-level work-flows and tools exploiting its rich data set of
calculated structural, thermodynamic, and electronic properties. Furthermore,
federating these tools would open the door to collaborative investigation of
the data by an unprecedented extended community of users to accelerate the
advancement of computational materials design and development.
