Examples of calling Slack Web API method via HTTP with axios

slackapi-async-await.js

const axios = require('axios');
const qs = require('qs');

const apiUrl = 'https://slack.com/api';

const greet = () => {
  let messageArgs = {
    token: process.env.SLACK_ACCESS_TOKEN,
    channel: '#cats', 
    text: ':wave: Hello, welcome to the channel!',
  };
  post(messageArgs);
};

const post = async(args) => { 
  const result = await axios.post(`${apiUrl}/chat.postMessage`, qs.stringify(args));
  try {
    console.log(result.data);
  } catch(e) {
    console.log(e);
  }
};

// pseudo code. you should be using the events API, but I omit the part for now
// when(a new user joined) 
greet();

slackapi-pagination-async-await.js

const axios = require('axios');
const qs = require('qs');

const apiUrl = 'https://slack.com/api';

/*
 *  Get a list of authorized channels
 */
const findAuthedChannels = async(id, cursor) => {

  const args = {
    token: process.env.SLACK_ACCESS_TOKEN,
    exclude_archived: true,
    user: id
  };

  if (cursor) args.cursor = cursor;

  const result = await axios.post(`${apiUrl}/users.conversations`, qs.stringify(args));

  const { channels, response_metadata } = result.data;

  if (response_metadata.next_cursor !== '') {
    return channels.concat(await findAuthedChannels(id, response_metadata.next_cursor));
  } else {
    return channels;
  }
  
};

const chList = await channels.findAuthedChannels(bot);

slackapi-pagination-promise.js

const axios = require('axios');
const qs = require('qs');

const apiUrl = 'https://slack.com/api';

/*
 *  Get a list of authorized channels
 */
const findAuthedChannels = (id, cursor) => new Promise((resolve, reject) =>  {

  const args = {
    token: process.env.SLACK_ACCESS_TOKEN,
    exclude_archived: true,
    user: id
  };

  if (cursor) args.cursor = cursor;

 axios.post(`${apiUrl}/users.conversations`, qs.stringify(args))
  .then((result => {
    const { channels, response_metadata } = result.data;
    
    if (response_metadata.next_cursor !== '') {
      resolve(findAuthedChannels(id, response_metadata.next_cursor)
        .then(nextResult => channel.concat(nextResult)))
    } else {
      resolve(channels);
    }
  }))
  .catch((err) => { 
    console.log(err);
  });
});

findAuthedChannels(cursor).then((result) => {
  const chList = result;
});

slackapi-promise.js

const axios = require('axios');
const qs = require('qs');

const apiUrl = 'https://slack.com/api';

const greet = () => {
  let messageArgs = {
    token: process.env.SLACK_ACCESS_TOKEN,
    channel: '#cats', 
    text: ':wave: Hello, welcome to the channel!',
  };
  post(messageArgs);
};

const post = (args) => { 
  axios.post(`${apiUrl}/chat.postMessage`, qs.stringify(args))
  .then((result => {
    console.log(result.data);
  }))
  .catch((err) => {
    console.log(err);
  });
};

// pseudo code. you should be using the events API, but I omit the part for now
// when(a new user joined) 
greet();