Recurring (daily) messages to a specific channel by my Slack App

Question

I\'m writing a slack app which provides some stats about a service by demand using slash commands.

The command calls my web api, I calculate stuff and return a forma

Answer 1

No. Slack does currently not provide a "scheduling" function in its API for calling an external service.

So you need to either use a local scheduling service (e.g. cron) on your server or an external web-based scheduling service. I personally use for my apps a free service called cron-job.org, which provides exactly the kind of functionality that you are requesting.