Known API Commands for my reference.

Login        - POST http://discordapp.com/api/auth/login


Send Message - POST http://discordapp.com/api/channels/CHANNELID/messages
Get Messages - GET  http://discordapp.com/api/channels/CHANNELID/messages

About Self   - GET  http://discordapp.com/api/users/@me
Guild List   - GET  http://discordapp.com/api/users/@me/guilds
PM Channels  - GET  http://discordapp.com/api/users/@me/channels

Above commands, you can remove @me with a specific user id to view that users information.

Channel List  - GET http://discordapp.com/api/guilds/GUILDID/channels
Guild Members - GET http://discordapp.com/api/guilds/GUILDID/members