Apps consume a lot of web services these days. Sometimes, these new services can be fantastic, and other times not so much. Learning how to evaluate APIs and identify problem areas before jumping head first into development can save us frustration, time, and money. This session will walk through evaluating an API, best practices, and red flags, all from the standpoint of an iOS dev. No matter your experience level, you'll leave with the skills to effectively tackle your next API.

1. APIs:
The good, the bad, the ugly
@MicheleTitolo

4. What we’ll cover

5. Documentation

6. The Good

7. It exists

8. Bonus: it’s interactive

9. I/O Docs

10. The Bad

11. Docs aren’t updated

12. The Ugly

13. Documentation?

15. URLs

16. The Good

17. Consistency

18. /users/22445
/products/3156
/movies/127/times

19. The Bad

20. Inconsistency

21. /users/22445
/reviews/3156
/times/127
Not review or time id’s

22. The Ugly

23. “Send GET to /remove to
delete”

25. Payloads

26. The Good

28. You have all the data you need

29. The Bad

30. Endpoint “id” field
/products id
/products/:id productID
/cart product_id

31. Yes, this actually happened

32. Change

33. We expect certain things

34. ...like image urls having http://

35. ...like dates sent in the same
format

36. We expect certain things
to not change

37. The Ugly

38. JSON containing HTML

41. Unstable

43. Authentication

44. The Good

45. HTTP Basc Auth over SSL

46. ...when SSL is secure

47. OAuth

48. The Bad

49. OAuth

51. The Ugly

54. Authorization

55. The Good

56. App requests permissions

57. The Bad

58. A single API key

59. The Ugly

60. Authorization?

61. goto fail;

64. Errors

65. The Good

66. Error codes

67. Error message in response

68. Human readable error
message

69. The Bad

70. “There was an error”

72. The Ugly

76. Caching

77. The Good

78. Using one of the standards

79. Cache-Control

80. If-Modified-Since

81. etags

82. The Bad

83. Manually processing data

84. The Ugly

85. Caching

88. In Summary

89. Consistency

90. Conventions

91. Simple

92. Questions?
@MicheleTitolo

93. • JSONSchema, RAML, API Blueprint,
• HTTP 1.1 Spec: http://www.w3.org/Protocols/rfc2616/
rfc2616.html
• Charles, Postman
• http://runscope.com, also http://newrelic.com for
backend analytics
• Versioning: http://apiux.com/2013/05/14/api-
versioning/
Q&A Resources