Slack 绿色博客

We marked messages unread in a channel, a DM and a thread in Slack web, read the read state back from the API, and timed what clears it.

We gave a Slack bot one scope, called 44 common Web API methods, and read the needed field of every missing_scope error. Then we added the scopes and called them again. The table shows which scope clears each method.

We uploaded files of 50 MB, exactly 1 GiB and 1 GiB plus one byte to Slack through its upload API. The limit is 1,073,741,824 bytes, and a failed upload can still leave a broken file behind.

Slack's dark mode is under Preferences > Appearance > Color Mode, with Light, Dark and System. We switched modes in Slack web with three test emoji and measured which ones vanish.

The Activity tab collects mentions, reactions, thread replies, reminders and DMs in one feed. We sent a mention and a /remind to a test account and opened every Activity setting in Slack web.

Slack channel names take lowercase letters, numbers, hyphens, underscores and letters from other scripts, up to 80 characters. We sent 45 names to the Slack app and the API and recorded every error.

We archived, unarchived and deleted channels in Slack web and through the API, and recorded what members see, what apps can still do, and which names stay taken.

How to call the Slack Web API from Postman with a bearer token and variables, plus a 16-request collection we ran against a real workspace with newman: 16 requests, 17 assertions, 0 failures, and the five mistakes it checks.

Slack has one spell check switch, under Preferences > Language & region. In our test browser it was on, yet Slack web showed no red underlines: the Grammarly extension had set spellcheck to false on the message box. How to check yours.

We opened a modal with seven input blocks in a test workspace and captured every payload: what Slack checks before your app sees anything, the exact view_submission state.values, response_action errors, dispatch_action, and input blocks in messages.

We uploaded six workspace icons to a test Slack workspace: 100 px, 1024 px, a wide image, a transparent PNG and two oversize files. What Slack accepted, what it stored, and how to remove an icon.

We renamed a free-plan Slack workspace and watched what changed: the sidebar, the search box and the default icon updated in an open tab within seconds, and the URL stayed the same.

The topic sits in the channel header; the description shows in the channel intro and the channel browser. We set both in the Slack UI and with conversations.setTopic and setPurpose and measured the limits.

Seven ways people fake an active Slack status, which ones hold up, and the thing that gives most people away. It isn't the dot.

A normal workday has about five moments where Slack flips you to away. Here's each one, in order, and the cheapest fix for it.

Slack only has two availability states, and neither one is yellow. If you see a yellow dot, it's a theme, an emoji, or a different app.

The Slack Calls API shows a call from your own video or phone service as a card in Slack. We ran calls.add, the call block, participants and calls.end in a test workspace and list every response and error.

Slack has no download or export button for canvases. We checked every menu on a test canvas, used Print canvas for PDF, and turned the API's HTML download into clean Markdown with a script we ran.

Slack forwards one message at a time. We checked the message menu, shift-click and the forward dialog, then tested three ways to move 10 messages at once: a thread, a copied range, and a script that posts links.

Working PowerShell for Slack: Invoke-RestMethod to a webhook, chat.postMessage with a bot token, Block Kit, and a file upload. Every script was run in PowerShell 7.6.6 against a real Slack workspace, with its output.

We renamed a Slack app and its bot user eight times in a test workspace. Which names changed, how fast Slack showed them, the App Home edit that never reached Slack, and the exact validation messages.

We called users.setPhoto 18 times on a test Slack workspace: PNG, JPEG and GIF, crop boxes, a 27 MB file and a broken one. What Slack stored, the errors, and how fast the new photo showed up.

A tested alertmanager.yml for Slack, the messages Prometheus alerts produced, a custom title and text template, and what send_resolved, group_by and color changed. Plus a typo amtool did not catch.

We sent Grafana alerts to Slack through both kinds of contact point, then replaced the default message with a notification template. The messages Slack showed, the delays, the template we used and the errors Grafana logged.

We ran the Jenkins Slack Notification plugin against a real Slack app: the pipeline that worked, the botUser setting that makes slackSend fail with a 404, threads, Block Kit, and the errors for channels the bot cannot see.

We ran 8 Slack node operations in n8n with a bot token, a user token and the OAuth2 credential. What each one can do, the errors you get, and two traps: the OAuth2 callback and the status expiration time zone.

We ran the n8n Slack Trigger against a real Slack app: which URL passes Slack's challenge, why a test event can arrive a minute late, why a channel the bot is not in stays silent, and how the bot can trigger itself.

We ran the pablovarela/slack Terraform provider against a real Slack workspace: create, update, drift, import, adopt and destroy a channel, plus the exact errors for bad names and missing scopes.

Slack publishes no fixed IP range for the requests it sends to your app. We logged 80 real requests from Slack over 73 minutes: 58 different addresses, all in AWS us-east-1. What that means for a firewall allowlist, and what to check instead.

A complete Slack app on FastAPI with Bolt for Python's adapter: a slash command, a button and an app mention, run behind a tunnel in a real workspace. We timed the acks, pushed one past 3 seconds and broke the signature on purpose.