An Automation Method of SLA Contract of Web APIs and Its Platform Based on Blockchain Concept

As the number of Web APIs is rapidly increasing, it is an urgent issue to discover qualified Web APIs and provide value-added services by orchestrating them. However, most of the interface descriptions of Web APIs are informal, and the Web API SLA contracts, which are a key to quality of services orchestration, require manual operations at the consumers. Meanwhile, applying the blockchain, the distributed ledger technology, to various domains beyond Fintech is attracting attention because of its fault-tolerant and anti-tampering. However, it isn't applied to Web API SLA contracts, yet. In this article, the authors propose a formal specification description of Web APIs together with its associated SLA specifications based on RDF, and an SLA contract method based on the common SLA contract platform built on the blockchain. We implemented the prototype of the SLA contract platform, and applied it to the examples for demonstrating its feasibility. Those experiences prove the feasibility of the proposed Web API SLA contract method and its supporting platform.