Hello, I have a huge experience working with APIs, from all perspectives:
1) Connect your application to an external API, using a SOAP system call. I did this by connecting to Banks, Assurance Institutions, and other companies requirent strong security and reliability.
2) Developing a API to connect two applications using JSON, XML or others formats, and securing the connection using state of art encryption openssl_encrypt.
3) Developing a API to provide or expose local data to remote clients, using, again, JSON, XML or others formats, and high-end encryption protocols.
So whatever you need I believe I can help you fast, and at the best price.
Please contact me to discuss the details.