Slack

export default (req, res) => {
  const { token, text } = req.body;

  if (token !== process.env.SLACK_TOKEN) {
    return res.status(400);
  }

  const textUrl = text && `/says/${text}`;

  return res.status(200).json({
    response_type: 'in_channel',
    text: `https://cataas.com/cat${textUrl}`
  });
};

Usage

First, create a Slack app. If you don't have an organization yet, you'll also need to create one.

With your app created, you can define a slash command.

1. Navigate to "Slash Commands" and click "Create New Command".
2. Fill out the form using the deployed URL for your function.
3. Hit "Save".

Navigate back to "Basic Information" click "Install App to Workspace". Make note of the Verification Token. We need to add this as an environment variable.

To securely access the API, we need to include the secret with each request. We also do not want to commit secrets to git. Thus, we should use an environment variable. Learn how to add environment variables in Vercel.