Slack Green Blog

We posted Slack's new carousel and card blocks into a channel and opened alert blocks in a modal, then pushed every field past its limit. Real screenshots, exact errors and the rule that keeps alerts out of messages.

We posted context, header, divider and actions blocks with a bot token and measured the limits, the errors and how Slack's web app draws each one, including the '+ N more' button cut-off.

Slack's Jump to date menu hides in the date divider above messages. We tested it in a 500-message channel and an older channel: which options appear, how far back the calendar goes, and how to do it by API.

Slack's Web API has no single unread-messages call. We tested what conversations.info returns for channels and DMs, counted unreads from last_read, and moved the sidebar badge with conversations.mark.

Slack's custom theme now takes 4 colors. We pasted old 8-color strings, Slack's own Share output and our own themes into Import, and logged which ones Slack accepted.

We switched one Slack app from assistant_view to agent_view and recorded what the user sees, which events arrive, and which status and title calls still work.

Slack's notification schedule is now called Working hours, under Preferences > Availability. How to set it, why it cannot be turned off, and what we logged when a scheduled pause started in a test workspace.

Away is the grey dot, inactive is a billing status after 28 days without Slack, and deactivated is an account an admin turned off. We checked where each one shows in a real workspace admin page.

We broke a real Slack incoming webhook 25 ways and logged each answer: 403 invalid_token, 404 no_service, no_team, no_active_hooks, 400 invalid_payload, no_text, invalid_blocks and silent 301 redirects.

Slack apps can add two kinds of shortcut: global ones in the composer's shortcut list and message ones in a message's menu. We added one of each, found where Slack puts them, logged both payloads and recorded what users see when the app does not answer.

We posted Slack's datepicker, timepicker and datetimepicker in a message and a modal, picked values and logged every payload. The datetimepicker returns a Unix timestamp; the timepicker returns a bare HH:mm with no zone unless you set one.

A Slack Block Kit button has three looks: no style, primary (green) and danger (red). We posted every kind, clicked each one, logged the block_actions payloads and recorded the errors for colors, disabled buttons and long labels.

To test a Slack API connection, call api.test for the network and auth.test for the token. We ran both with no token, a bot token, a user token, an app-level token and a revoked token, and found that api.test echoes your token back.

Message metadata is a hidden JSON object an app attaches to a message. We posted it with chat.postMessage, read it back, grew it past the limit and logged every event. Bad metadata does not fail the call; Slack drops it and posts the message anyway.

conversations.info returns one channel's name, topic, purpose and flags from its ID. We called it on a public, private, archived and DM channel with a test bot and recorded every field and error.

@slack/web-api 8.2.0 runs on Node 20 or newer and sends requests with fetch. We posted, paginated, caught a Slack error and a rate limit in TypeScript, and found that the v7 agent option for proxies is silently ignored in v8.

slack-go/slack v0.29.0 is the Go client most people use for the Slack API. We ran a program that posts, reads back and updates a Block Kit message, a Socket Mode bot that answers a mention, and a loop that hit the rate limit, with the output and error types we got.

slack-ruby-client 3.2.0 is the Ruby gem for the Slack Web API. We installed it, posted, read back, reacted and paginated against a real workspace, and recorded the error classes it raised, including the rate-limit error that a rescue of SlackError does not catch.

Slack does not tell anyone when you change your status. An app can find out within a second through the user_status_changed and user_change events. We changed a status 7 ways and timed each event, including statuses that expired.

You cannot type a checkbox into a Slack message. We tried the composer, mrkdwn, a markdown block, a rich_text checklist and a Block Kit checkboxes element, and show which ones render and which ones a person can actually tick.

A Slack canvas is private to the people and channels it is shared with, unless you switch workspace access on. We made a canvas in a public channel, a private channel and a DM, then checked who could open each one.

Shift+Esc marks every Slack channel, DM and Activity item as read after one confirm dialog; Esc clears one conversation. Where the Unreads view (the old All Unreads) is, its shortcut, and what client.counts showed before and after, tested 3 October.

In current Slack, muting a channel also hides it from the sidebar until you turn off one checkbox in Preferences. We muted a test channel, had a bot post and then @mention us in it, and recorded what the sidebar, the badge and Activity showed each time.

Slack channel bookmarks now live in folder tabs above the messages, not in a bookmarks bar. We added, moved and deleted them in a test channel and through the bookmarks API, and found the delete that hides bookmarks the API still lists.

We built a Work Object unfurl for a fake ticket tracker in a free Slack workspace: the manifest setting, the chat.unfurl metadata that rendered the card, the entity_details_requested event behind the flexpane, and every error on the way.

We subscribed a test app to 37 bot events, did 46 things in Slack, and logged every event that reached our HTTP endpoint: which event each action sends, which actions send two or four, which send none, and how long each took.

A Bolt for Python app over HTTP that answers a message, a slash command and a button through the Flask adapter, then the same app as AsyncApp on aiohttp. Console logs from a real run, and the errors a wrong signing secret and an unhandled event gave.

We streamed a bot reply into a Slack DM thread with chat.startStream, chat.appendStream and chat.stopStream, timed every call, screenshotted the thread mid-stream, and found how long an idle stream stays open.

We posted a plan block with tasks in all four statuses and standalone task cards from a bot, updated them with chat.update, and probed the limits. pending works only inside a plan, and titles have no length limit we could find.

We opened a Slack modal, pushed views until Slack refused, updated the top view with a current and a stale hash, and answered view_submission with every response_action. Every response and what the user saw.