What are some OFX (Open Financial Exchange) APIs?

Question

I am planning to develop a small application which displays my bank account details(like Mint.com) where I can customize the display of my own. I want to know how and where to start.

1. Where these OFX API's are available?
2. Are they free or we need to pay and get access to those API?
3. What is data format ( xml, xml/atom, json) ?
4. Any article or document to understand this requirement and start developing?
5. Any open source software where I can download the code and customize it?

If I want to develop a application like Mint.com what are the other companies provide API's other than Yoodlee? What is the pricing like?

Answer 1

As others have mentioned, Yodlee is the only company providing a high-level interface to this kind of data. They are also fairly expensive and the API is meant for big-time products, not personal projects.

As for your OFX questions,

Q: Where these OFX API's are available?

A: http://ofx.net

Q: Are they free or we need to pay and get access to those API?

A: They are free and open. The list of server URLs are a bit more tricky to acquire. There is an open wiki-type list of OFX servers at OfxHome, but beware of copying that data wholesale as bank OFX connection information should be verified multiple times over. You obviously don't want to send customers to a trojan OFX server that a random person got inserted into ofxhome.com.

Q: What is data format ( xml, xml/atom, json) ?

A: OFX 1.* used SGML but OFX 2.* (which I've not encountered in the wild) uses XML.

Q: Any article or document to understand this requirement and start developing?

A: ofx.net has very complete specifications of the OFX protocol which is mainly an exchange of OFX-format files over https.

Q: Any open source software where I can download the code and customize it?

A: Sorry, I don't know of any C# software to talk OFX

Hope this helps, Sean