We do offer access to the data that makes up the graph depicting trends in on-time repayment rates at Zidisha: https://www.zidisha.org/index.php?p=114

It generates a simple table with the repayment performance of each of the 6000+ loans that have been funded through our platform, with links to the individual loan profile pages.

We'd definitely like to offer an API similar to Kiva's, when web development resources allow.