how do I program a slackbot to send a regular message automatically every week

Question

I am building a slackbot that will remind people in my organisation to perform certain admin (hours expenses etc) every week. I know this can be very easily done by each person creating a recurring reminder. What i want is to create a bot that will send a preconfigured message to people every week. I've looked online extensively, and haven't yet found out how slackbot can send a message without an event or being otherwise prompted.

I'm currently testing this on a local ngrok server with the following backend:

const { WebClient } = require('@slack/web-api');
const { createEventAdapter } = require('@slack/events-api');

const slackSigningSecret = process.env.SLACK_SIGNING_SECRET;
const slackToken = process.env.SLACK_TOKEN;
const port = process.env.SLACK_PORT || 3000;

const slackEvents = createEventAdapter(slackSigningSecret);
const slackClient = new WebClient(slackToken);

slackEvents.on('app_mention', (event) => {
    console.log(`Got message from user ${event.user}: ${event.text}`);
    (async () => {
        try {
            await slackClient.chat.postMessage({ channel: event.channel, text: `Hello <@${event.user}>! Have you completed your Time sheets for this week yet?` })
        } catch (error) {
            console.log(error.data)
        }
    })();
});


slackEvents.on('error', console.error);

slackEvents.start(port).then(() => {
    console.log(`Server started on port ${port}`)
});

Once this reminder is done, i intend to build upon it (more features, just need a beginning) so please don't recommend alternative ways my organisation can send reminders to people.

Answer 1

You can try using the chat.scheduleMessage method instead (https://api.slack.com/methods/chat.scheduleMessage). Since you won't rely on an event you may want to store the necessary conversations ids so that they're ready when the app needs to call the method.