Slack analyzer is a GitHub Action to fetch all users from a Slack workspace and determine when they joined and potentially left the workspace. This is used as a proxy for tenure with a company.

The result is a README file with a graph showing turnover month over month, some statistics and a boxplot for tenure durations, and three Markdown tables showing when the current employees joined, the tenures of all employees ever by join date, and all tenures by duration. The README links to all relevant files.

Example for all tenures

Example for current tenures	Example for tenures by duration

Optionally, the action output can be used to send the latest diff and the graph to a Telegram channel.

Example Telegram diff message	Example Telegram graph message

Required The name of the workspace/company to be used in the output file headings.

Required A Slack API bot token with the users:read scope for the workspace; this is required to fetch the list of users from the workspace.

Required A Slack API user token with the search:read scope for the workspace; this is required to fetch the first and last message of a user.

Optional A Telegram channel ID; this isn't required, but the action exits with an error status if it is missing.

Optional A Telegram authorization token; this isn't required, but the action exits with an error status if it is missing.

This includes the optional Telegram notifications.

name: Update tenures and graph

on:
  # Manual trigger
  workflow_dispatch:

  # Every day at 11:00 and 22:00 UTC
  schedule:
    - cron: 0 11,22 * * *

env:
  # Optionally set timezone
  TZ: America/Toronto

jobs:
  update:
    name: Update tenures and graph
    runs-on: ubuntu-22.04

  steps:
    - name: Check out repository
      uses: actions/checkout@v2

    - name: Update Slack workspace analysis
      uses: bewuethr/slack-analyzer@v0
      with:
        name: Foo Corp
        slack-bot-token: ${{ secrets.BOT_TOKEN }}
        slack-user-token: ${{ secrets.USER_TOKEN }}
        telegram-to: ${{ secrets.TELEGRAM_TO }}
        telegram-token: ${{ secrets.TELEGRAM_TOKEN }}

For details about using Telegram, see Publishing updates to a Telegram channel.

• An employee is assumed to have joined the company at the date of their first public Slack message
• They are assumed to have left the company at the date of their last public Slack message
• If no message can be found for a new user, the current time is used as an estimate of when they joined
• Employee numbers are assigned in ascending order of the timestamp of the first message; this isn't necessarily the true order, especially not for employees who joined before the company started using Slack – see corrections.csv below for a fix

• Get all users: users.list
• Find first/last message of a user: search.messages, queried with from:<@USERID>; this means that the result depends on the user who owns the USER_TOKEN and which private channels they have access to

Calls to search.messages retry once on error; because curl's --retry option respects the Retry-After header, this slows down requests just enough when hitting the rate limit.

• README.md contains the turnover graph and links to the other Markdown files and data sources

• data/tenures.tsv contains the tab-separated data for all users with Slack ID, name, title, status, and Unix timestamp of first and last message, where applicable; status can be one of

  • active: user is still active member of the workspace
  • alum: user is marked deleted and has a "last" timestamp
  • fresh: user just joined the workspace; this is replaced with active right afterwards, either with the timestamp of their first message, or the current time

• data/corrections.csv is an optional file containing corrections for known incorrect values; it uses four comma-separated columns:

  Heading	Meaning
  id	the ID of the user to which the correction applies
  delete	set to true if the user should be removed
  first	Unix timestamp for join date
  last	Unix timestamp for departure date

  See Manually correcting data from Slack for more details.

• tenures.md is the Markdown-formatted view of the data/tenures.tsv with human-readable datestamps, ordered by join date

• tenurescurrent.md is the Markdown-formatted view of tenures.tsv with only current employees

• tenuresduration.md is like tenures.md, but ordered by duration instead of join date; rows with former employees are set in italics

• The diffs/YYYY/MM/*.diff files contain the unified diffs of the TSV data between two updates, grouped in year and month subdirectories

• data/turnover.tsv is generated from tenures.tsv to be used as input for the script that generates the turnover graph; it is committed so it can serve as an indicator if the graph should be regenerated or not

• turnover.svg is the graph used in README.md

• boxplot.svg is the boxplot used in README.md

For more details about the implementation, see Implementation notes.