Amazon products API - Looking for basic overview and information
Your post contains several questions, so I'll try to answer them one at a time:
- The API you're interested in is the Product Advertising API (PA). It allows you programmatic access to search and retrieve product information from Amazon's catalog. If you're having trouble finding information on the API, that's because the web service has undergone two name changes in recent history: it was also known as ECS and AAWS.
- The signature process you're referring to is the same HMAC signature that all of the other AWS services use for authentication. All that's required to sign your requests to the Product Advertising API is a function to compute a SHA-1 hash and and AWS developer key. For more information, see the section of the developer documentation on signing requests.
- As far as I know, there is no support for retrieving RSS feeds of products or tags through PA. If anyone has information suggesting otherwise, please correct me.
- Either the REST or SOAP APIs should make your use case very straight forward. Amazon provides a fairly basic "getting started" guide available here. As well, you can view the complete API developer documentation here.
Although the documentation is a little hard to find (likely due to all the name changes), the PA API is very well documented and rather elegant. With a modicum of elbow grease and some previous experience in calling out to web services, you shouldn't have any trouble getting the information you need from the API.
I agree that Amazon appears to be intentionally obfuscating even how to find the API documentation, as well as use it. I'm just speculating though.
Renaming the services from "ECS" to "Product Advertising API" was probably also not the best move, it essentially invalidated all that Google mojo they had built up over time.
It took me quite a while to 'discover' this updated link for the Product Advertising API. I don't remember being able to easily discover it through the typical 'Developer' link on the Amazon webpage. This documentation appears to valid and what I've worked from recently.
The change to authentication procedures also seems to add further complexity, but I'm sure they have a reason for it.
I use SOAP via C# to communicate with Amazon Product API.
With the REST API you have to encrypt the whole URL in a fairly specific way. The params have to be sorted, etc. There is just more to do. With the SOAP API, you just encrypt the operation+timestamp, and thats it.
Adam O'Neil's post here, How to get album, dvd, and blueray cover art from Amazon, walks through the SOAP with C# method. Its not the original sample I pulled down, and contrary to his comment, it was not an official Amazon sample I stumbled on, though the code looks identical. However, Adam does a good job at presenting all the necessary steps. I wish I could credit the original author.