مدونة سلاك جرين

A Slack bot that answers @mentions with a model running in Ollama on your own server, in 34 lines of Bolt for Python over Socket Mode. We ran it on 9 November 2026 with qwen2.5:1.5b on a busy CPU-only box and timed every reply.

Block Kit has no progress bar element, so a Slack progress bar is text you redraw with chat.update. We drew one three ways on 9 November 2026, timed every update, and pushed chat.update until Slack answered ratelimited.

Slack has no built-in welcome message per channel, and Workflow Builder is closed to Free workspaces. A 30-line Bolt app that listens for member_joined_channel does the job on any plan. We ran it on 9 November 2026 and timed the welcome.

An incoming webhook cannot upload a file. It can show an image from a public URL in an image block, or a link Slack unfurls. For a real file you need a bot token and the upload API. Every payload we tried on 9 November 2026, with Slack's answer.

An incoming webhook can post, reply in a thread and do little else. A bot token can also edit, delete, upload files, pick the channel and post as a custom name. We sent the same Block Kit message both ways on 9 November 2026 and recorded each answer.

Send a Slack message when Claude Code finishes or needs your approval, with a Stop hook, a Notification hook and an incoming webhook. We ran the setup on Claude Code 2.1.311 on 9 November 2026 and recorded what each hook sent, when, and the three things that broke.

A Slack bot on localhost needs a public HTTPS URL for events and slash commands, or Socket Mode. We tried ngrok 3.39.13 with no account (ERR_NGROK_4018), a Cloudflare quick tunnel and Socket Mode on 8 November 2026, timed the replies, and broke the tunnel URL on purpose.

To build a Slack bot in Django, mount Bolt for Python's Django adapter on one URL and let it handle slash commands and events; for error alerts, add a logging handler that posts to an incoming webhook. We ran both on Django 6.1.3 on 8 November 2026 and checked which django-slack packages still work.

The Slack Java SDK is com.slack.api:slack-api-client for Web API calls and com.slack.api:bolt for apps. We ran version 1.54.0 with Gradle on 8 November 2026: chat.postMessage, conversations.history with a cursor, a Socket Mode Bolt app and a Kotlin Block Kit post, plus the silent failure in ctx.say.

Home Assistant's Slack integration sends notifications with a bot token through the notify.slack action, including Block Kit and file uploads. We set it up on Home Assistant 2026.11.0 on 8 November 2026, hit the missing-scope errors that stop file uploads, and set a Slack status from an automation.

Node-RED can post to Slack with a plain http request node and an incoming webhook, call any Slack API method with node-red-contrib-slack, and receive mentions over Socket Mode with node-red-contrib-slack-modern. We ran all three on Node-RED 5.0.9 on 8 November 2026.

A 36-line logging module posts ERROR records to a Slack incoming webhook with only the standard library. We ran it on Python 3.12 on 7 November 2026, sent 50 errors in a burst with and without a queue, and tried four PyPI Slack logger packages; one of them failed with invalid_auth.

winston-slack-webhook-transport sends winston logs to a Slack incoming webhook: add it as a transport with webhookUrl and level error. We ran version 2.3.7 with winston 3.19 on Node 22 on 7 November 2026, sent 50 errors at once, and found two things the README does not say: the burst arrived out of order, and Error stacks need format.errors.

Airflow sends Slack alerts through the Slack provider: send_slack_webhook_notification or send_slack_notification as an on_failure_callback, or SlackWebhookOperator and SlackAPIPostOperator as tasks. We ran all four on Airflow 3.4.0 with provider 9.11.1 on 7 November 2026, plus the two mistakes that silently cost you alerts.

Slack can turn a group DM into a private channel: open the conversation details, go to Settings and click Change to a private channel. A one-to-one DM has no such option. We converted a group DM on 7 November 2026 and recorded what moved, what changed and what the dialog refused.

A Slack file block shows a file card inside a message. It takes source "remote" plus an external_id or file_id, and the file must exist first. We added remote files with files.remote.add, posted them in file blocks, and tried the mistakes, on 7 November 2026.

A Block Kit video block needs video_url, thumbnail_url, title and alt_text, and its video_url must be an embeddable player URL on a domain your app claims. We made 26 posts with a bot token on 7 November 2026; a YouTube /embed/ URL worked with no setup, and every other host needed claimed unfurl domains plus a reinstall.

Slack has no official .NET SDK. We posted to Slack from C# two ways on .NET 10 on 5 November 2026: plain HttpClient with System.Text.Json, and the SlackNet package with a Block Kit section. Both versions, their real output and how each reports a bad channel.

Two tested ways to call the Slack API from PHP: plain curl with a bot token, and the jolicode/slack-php-api client. We ran both on PHP 8.5 on 5 November 2026, posted a message, read history and caught a bad channel ID. Code and output below.

Three ways to post to Slack from Rails, run on Ruby 3.4 and Rails 8.1 on 5 November 2026: plain Net::HTTP to a webhook, the slack-notifier gem (last release 2021, still works), and slack-ruby-client with a bot token. Plus exception_notification sending a real error to Slack.

Uptime Kuma posts to Slack through an incoming webhook. We ran Uptime Kuma 2.5.9 in Docker, took a test site down twice and timed the alerts: 49 to 56 seconds for Down at a 20-second interval, 16 to 17 seconds for Up. Settings, message formats and a working template below.

Sign in with Slack is OpenID Connect on top of OAuth 2.0: send the user to slack.com/openid/connect/authorize, swap the code at openid.connect.token, and check the RS256 id_token. We ran the whole flow on 5 November 2026 and show the real claims and errors.

Open your account's Access Logs page (my.slack.com/account/logs). It lists every sign-in with the app, IP address, time and login count, and lets you download a CSV. We read ours on 5 November 2026, including the entry a Sign in with Slack app leaves.

Slack has no official Rust SDK. The community crate that works today is slack-morphism: on 5 November 2026 we used version 2.31.1 to post a message, page through history with a cursor and answer a mention over Socket Mode. Code and output below.

A Slack deep link is a slack:// URL such as slack://channel?team=T123&id=C123 that opens the desktop or mobile app on a channel, person, file or setting. We read the handler in Slack's current code, listed the commands it accepts, and tested the https fallbacks.

Slack has no sort that lifts unread channels to the top. The closest is Filter and sort > Unreads, which hides every read channel. We tried each sort and filter in the sidebar with one unread channel and screenshot the order.

Slack lets a member delete only their own messages. Someone else's message, a 'joined the channel' line and workspaces where admins turned deletion off all fail. We ran each case from a member account and recorded the exact error.

The grey LEGACY tag marks messages from the old, automated Slackbot in your Slackbot DM. Slack shows it on Free and Pro workspaces to tell those notices apart from the new AI Slackbot. We read the code that draws it.

A public channel can be found, read and searched by every full member of the workspace, even before they join. A private channel is invisible to anyone who is not in it. We tested both from a member account.

Open the profile, click the three-dot button and choose Copy link to profile. Slack copies a link in the form https://yourworkspace.slack.com/team/U0123ABCDEF. We tested what that link does for a member, for someone signed out, and inside a message.