I need to access a mainframe API from a webpage/browser. The mainframe API is accessible to the webserver but not exposed to the web.
The API is returning 40000 bytes of data per packet, it is using the CICS.LU6.2 protocol.
I am planning to develop a node.js server on linux to expose the mainframe API to the web, i.e. making this a "web API", so that it can be used with angular.js to develop a website.
I did not find any adaptor/method to connect to the mainframe API in node.js.
If you absolutely need to retain an existing API flowing over LU 6.2, then you'll need some sort of gateway that can transform your web requests (most likely HTTP) to SNA LU 6.2. While you can write this yourself, there are several commercial products that can do some or all of this work for you.
One IBM solution is described here.
There are also solutions from third-party vendors like CA - here's a link to the CA API Management product. The third-party solutions often have other features that might be important to you, such as security and load-balancing or fault-tolerance.
Given that you're open to a Linux solution, you can also achieve something similar to CA's API Management solution using open-source technologies, such as the WSO2 stack or the Mule ESB. These are big decisions that go way beyond just bridging LU 6.2 to HTTP, but most of what you need can be done for free.
Your site very likely has a strategy for API management - if so, you should definitely figure out what your site standards are. Security and lots of other issues are difficult to get exactly right, so you'll want to be careful if this is your organization's first taste of exposing existing services to the web.