Prompts for a slack API token and exports all emoji from the associated instance to ./output. Get your token here: https://api.slack.com/docs/oauth-test-tokens. Use https://chrome.google.com/webstore/detail/slack-emoji-tools/anchoacphlfbdomdlomnbbfhcmcdmjej to import

export-slack-emoji.sh

#!/bin/bash
token=""
while [[ -z "$token" ]]; do
    read -s -p "Please enter your Slack token: " token
done
echo ""

mkdir -p output
list=$(curl https://slack.com/api/emoji.list?token=$token)
for key in $(echo $list | jq --raw-output '.emoji | keys | .[]'); do
  url=$(echo $list | jq --raw-output ".emoji[\"$key\"]")
  if [[ $url != alias* ]] ; then
     filename=$(basename "$url")
     ext="${filename##*.}"
     echo "$url -> output/$key.$ext"
     curl $url > output/$key.$ext
  fi
done