sends messages to a discord channel using a bot via http POST

discord-bot-post-message.py

# post a message to discord api via a bot
# bot must be added to the server and have write access to the channel
# you may need to connect with a websocket the first time you run the bot
#   use a library like discord.py to do so
import requests
import json

channelID = "your_id_goes_here" # enable dev mode on discord, right-click on the channel, copy ID
botToken = "your_token_here"    # get from the bot page. must be a bot, not a discord app

baseURL = "https://discordapp.com/api/channels/{}/messages".format(channelID)
headers = { "Authorization":"Bot {}".format(botToken),
            "User-Agent":"myBotThing (http://some.url, v0.1)",
            "Content-Type":"application/json", }

message = "hello world"

POSTedJSON =  json.dumps ( {"content":message} )

r = requests.post(baseURL, headers = headers, data = POSTedJSON)