Rate control, throttling and retrying Slack API method requests

Enable rate control

Slack API defines rate limits to which all of your applications must follow.

By default, throttler isn't enabled, so you should enable it explicitly:

use slack_morphism::prelude::*;
use slack_morphism_hyper::*;

let client = SlackClient::new(

The example above creates a Slack API Client that follows the official rate limits from Slack. Because the Slack rate limits apply per workspaces (separately), to use throttling and limits properly you have to specify team id in tokens:

let token_value: SlackApiTokenValue = config_env_var("SLACK_TEST_TOKEN")?.into();
let team_id: SlackTeamId = config_env_var("SLACK_TEST_TEAM_ID")?.into();
let token: SlackApiToken = SlackApiToken::new(token_value).with_team_id(team_id);

let session = client.open_session(&token);

Rate control params

You can also customise rate control params using SlackApiRateControlConfig:

  • To global rate limit all APIs and for all teams use: SlackApiRateControlConfig.global_max_rate_limit. Default is not limited.
  • To rate limit all APIs and each team separately: SlackApiRateControlConfig.team_max_rate_limit. Default is not limited.
  • To change default tiers limits use SlackApiRateControlConfig.tiers_limits. Defaults are following the Slack recommendations (almost, there are slight differences to optimize bursting for Tier1).

Enable automatic retry for rate exceeded requests

To enable automatic retry of Slack Web API method requests, you need to specify max_retries in rate control params (default value is 0):

    let client = SlackClient::new(