🦩 Leetcode daily challenge slack notifier

Published data: 21 January 2024

Leetcode is a website
where you can practice your coding skills by solving coding challenges.

Recently, my teammates and I have been doing the Leetcode daily challenge.

While it’s fun to do it, it’s also fun to share our solutions with each other. So I’ve decided to send us an automatic notification on Slack every day with the link to the challenge of the day.

tip

Slack reminders are a good option if you want just a static reminder, in our case we wanted the convenience of having more information about the daily problem in the message itself.

The GraphQL API

It is possible to access the public graphql API of leetcode to get the challenge of the day. The endpoint is https://leetcode.com/graphql. You can use the following query to get the challenge of the day:

query questionOfToday {
  activeDailyCodingChallengeQuestion {
    link
    question {
      title
      difficulty
      topicTags {
        name
      }
    }
  }
}

Make sure to modify the query to get the fields you want.

In our bash script, we can use curl to get the response from the graphql endpoint:

#!/usr/bin/env sh

# Get the graphql response from the leetcode endpoint
response=$(curl -s "https://leetcode.com/graphql?query=query%20questionOfToday%7BactiveDailyCodingChallengeQuestion%20%7B%20link%20%20question%20%7Btitle%20difficulty%20topicTags%20%7Bname%7D%7D%7D%7D")

The next steps is to parse the response using jq to get the relevant fields:

link="https://leetcode.com$(echo "$response" | jq -r '.data.activeDailyCodingChallengeQuestion.link')"
title=$(echo "$response" | jq -r '.data.activeDailyCodingChallengeQuestion.question.title')
difficulty=$(echo "$response" | jq -r '.data.activeDailyCodingChallengeQuestion.question.difficulty')
tags=$(echo "$response" | jq -r '.data.activeDailyCodingChallengeQuestion.question.topicTags[].name' | paste -sd ", " -)

Posting on slack

You can format the message in any way you want. I’ve decided to keep it simple:

# Encouragement
encouragement="💫 A leetcode a day keeps unemployment away"

# Format the message to be posted in slack
message="*<$link|$title>* | $difficulty\nTags: $tags\n\n $encouragement"

To actually post it on slack, you’ll need the Slack channel id and an auth token. Just put it in the script as environment variables:

channel="$SLACK_CHANNEL"
auth="$SLACK_AUTH"

# Post the message to slack using an incoming webhook
curl -X POST --data "{'channel':'$channel','blocks':[{'type':'section','text':{'type':'mrkdwn','text':'$message'}}]}" -H "Authorization: Bearer $auth" -H "Content-type: application/json" https://slack.com/api/chat.postMessage

Running the script

You can trigger the script in any way you find convenient. As I had easy access to Gitlab Schedule pipelines, I’ve decided to use it.

notify_slack:
  before_script:
    - apk add --update curl jq && rm -rf /var/cache/apk/*
  script:
    - chmod +x ./daily_challenge.sh
    - ./daily_challenge.sh

That is it! Now you can get your daily leetcode challenge on slack.