duckduckgo/zeroclickinfo-spice — pull request #831 by devongundry (2014-05-27 20:12:35+00:00)
Title: My first instant answer that displays the balance of a Bitcoin address is ready to go!

**What does your instant answer do?**

Shows the current, confirmed balance of any public Bitcoin address.

**What problem does your instant answer solve (Why is it better than organic links)?**

This solution is better than organic links because most public Bitcoin addresses are never indexed by search engines, thus when a user searches for one they usually get zero results.

The most common reason to search for a public address is to get a balance, either for one’s own address, or to determine if an address contains sufficient funds to cover a liability. Thus our Instant Answer returns the balance, the most common need.

To summarize:

Problem: searching a Bitcoin address yields no results
Solution: show the balance of an address when user searches it

**What is the data source for your instant answer? (Provide a link if possible)**

Chain.com, a block chain API service: https://chain.com/#docs-address

**Why did you choose this data source?**

Chain.com is the only supported API for this data source. See this blog post as an example of the company’s focus on API reliability: http://blog.chain.com/post/86919823336/chain-operations

**Are there any other alternative (better) data sources?**

Other services have had consistent, documented problems with up-time and accuracy. This is because other services provide block chain data as an afterthought to their core offering (such as a wallet), and thus do not dedicate resources to ensuring highly available, low latency access to block chain data.

**What are some example queries that trigger this instant answer?**

A user simply queries any public Bitcoin address. Here are three example searches:

17x23dNjXJLzGMev6R63uyRhMWP1VHawKc

1Gn2dRFqouUHvuWPVhriCDtP3qVQc59WHy

3QJmV3qfvL9SuYo34YihAf3sRCW3qSinyC

**Which communities will this instant answer be especially useful for? (gamers, book lovers, etc)**

Any individuals, institutions, services, or media entities that use, study, or report on Bitcoin

**Is this instant answer connected to a DuckDuckHack [instant answer idea](https://duck.co/ideas)?**

Yes, it was proposed here: https://duck.co/ideas/idea/372/zero-click-info-for-bitcoin-addresses

The proposer suggested using blockchain.info, but as mentioned above, it has poor availability and reliability, and thus we implemented the solution with Chain.com’s API

**Which existing instant answers will this one supersede/overlap with?**

None

**Are you having any problems? Do you need our help with anything?**

No, we were very pleased with the process!!

##Checklist
Please place an 'X' where appropriate.

```
[x] Added metadata and attribution information
[x] Wrote test file and added to t/ directory
[x] Verified that instant answer adheres to design guidelines(https://github.com/duckduckgo/duckduckgo-documentation/blob/master/duckduckhack/styleguides/design_styleguide.md)
[x] Tested cross-browser compatibility

Please let us know which browsers/devices you've tested on:
- Windows 8 // Tested on Browserstack.com
[y] Google Chrome
[y] Firefox
[y] Opera
[y] IE 10

- Windows 7 // Tested on Browserstack.com
[y] Google Chrome
[y] Firefox
[y] Opera
[y] IE 8
[y] IE 9
[y] IE 10

- Windows XP // Tested on Browserstack.com
[n!] IE 7 // Unable to test. Using Browserstack.com, DuckDuckGo itself would not render correctly. No spices would load at all.
[y] IE 8

- Mac OSX
[y] Google Chrome
[y] Firefox
[y] Opera
[y] Safari

- iOS (iPhone) // Tested on iPhone 5s
[y] Safari Mobile
[y] Google Chrome
[n!] Opera //Unable to connect locally with Browserstack

- iOS (iPad) // Tested on iPad Air
[y] Safari Mobile
[y] Google Chrome
[n!] Opera // Unable to connect locally with Browserstack

- Android // Tested on HTC One
[y] Firefox
[y] Native Browser
[y] Google Chrome
[y] Opera
```