Slack Green ブログ

We took a new app from 'Activate Public Distribution' greyed out to a working listing form on 2 October 2026. Four checks gate distribution, one HTTP redirect URL is enough to fail the HTTPS check, and the Marketplace asks for 10 active workspaces before you can submit.

We subscribed a Socket Mode app to message.channels, then posted, edited, deleted, replied in a thread, sent a reply to the channel and pasted a link. The raw event for each, three message_changed events nobody typed, and the filter that stopped our bot answering them.

We revoked a user token and a bot token with auth.revoke, then every token at once with the Revoke Tokens button, and logged each response, each event and what kept working. Then we reinstalled and checked the new tokens.

We called users.info and users.profile.get for a person, a bot and Slackbot, changed the person's display name in between, and logged which fields moved. Code, output, the email scope test and every user_not_found case we hit.

Slack paginates list methods with a cursor: pass response_metadata.next_cursor back as cursor until it is empty. We paged 27 real messages on 2 October 2026 and broke the cursor five ways to see which ones fail.

A Slack app created today cannot use the RTM API. We called rtm.connect and rtm.start with every token a new app gets on 2 October 2026, tried to request the rtm:stream scope, and ran the same bot over Socket Mode.

icon_emoji, icon_url and username only work with the chat:write.customize scope, and Slack ignores them silently without it. We tested every case on 2 October 2026, plus webhooks and the app icon upload limits.

We sent chat.postMessage with as_user=true, as_user=false and no as_user, with a bot token and a user token. as_user=true changed nothing, as_user=false was rejected, and only the user token posted under the person's name.

A Slack bot has three IDs: a user ID (U...), a bot ID (B...) and an app ID (A...). We called auth.test with a bot, user and app-level token on 2 October 2026 and show where each ID turns up.

We ran Slack's Add to Slack flow against a 34-line Python callback on localhost, then broke each step: a reused code, a typo, a wrong secret, a wrong redirect_uri, a cancelled consent screen and a code we held for 11 minutes.

With token rotation on, Slack access tokens start with xoxe. and expire after 12 hours. We turned it on for a test app on 2 October 2026, refreshed the token six times, and logged which old tokens kept working.

会社がノートPCのカメラであなたを見られるのは、ビデオ通話のあいだと、カメラをオンにするソフトを通してだけです。Windows 11とmacOSでカメラがオンかどうかの見分け方、Webカメラの写真を撮る監視ツール、法律が認める範囲をまとめました。

conversations.list returns every public channel but only the private channels your bot is in. We ran it with a bot token and a user token on 2 October 2026 and pasted what each one returned.

We posted rich_text blocks with every element type, lists nested 9 levels deep, quotes and code, then broke them on purpose. The JSON we sent, screenshots of how Slack web drew it, and the exact invalid_blocks errors.

Slackのフリープランで見られるのは直近90日のメッセージとファイルだけで、1年より古いデータは削除され、アプリは10個まで、ハドルとSlackコネクトは1対1だけです。ヘルプセンターに載っている制限の一覧、90日目に起きること、有料にする価値があるときをまとめました。

We added people and bots to public and private channels with conversations.invite and conversations.join, using a bot token and a user token. Every response we got, including already_in_channel, cant_invite_self, cant_invite and the force flag.

We called users.list with a bot token in a one-person workspace and got 14 members back: Slackbot, 1 person, 4 live bots and 8 deleted ones. The script, the curl call, cursor paging to the end, and what users:read.email changes.

Slackのメッセージで送信せずに改行するにはShift+Enterを押します。Enterで改行したいなら、環境設定の詳細設定で、メッセージを書くときのEnterキーを「改行する」に変え、Cmd+EnterかCtrl+Enterで送信します。スマホ、リスト、コードブロック、APIでの改行もまとめました。

Slackのアイコンの赤い点はどこかに未読があること、赤い数字はDM、メンション、キーワード、フォロー中のスレッドの返信を示します。Shift+Escですべて既読にし、スレッド、アクティビティ、To-Do、ほかのワークスペースを確認してから、キャッシュのクリアやOSのバッジのリセットをします。

We pointed a slash command at a local server and broke it on purpose: HTTP 500, 401 and 302, a wrong path, a dead tunnel, a stopped server and Socket Mode with no process. Each one gave dispatch_failed. A slow reply gave operation_timeout instead.

Slackのアプリが開かないときは、たいていウィンドウのないまま起動しているか、外したモニターにウィンドウがあります。Slackのプロセスをすべて終了して開き直し、だめならアプリのデータのリセット、再インストール、サインインのリンクの確認をします。Windows 11とMacの手順です。

Slackのメッセージのtextの上限は40,000字で、開発者向けドキュメントは4,000字未満を勧めています。APIで試すと、長い文は切られず4,000字ずつのメッセージに分けて投稿されました。Block Kitのセクションは3,000字、ヘッダーは150字まで。長いメッセージで起きること、ほかの文字数の制限、長い投稿の分け方をまとめました。

We clicked a button, a static_select and a datepicker in Slack on 1 October 2026 and logged the block_actions payloads our app received. Then we measured response_url: 5 posts, then used_url; it worked at 29:50 and was dead at 30:10.

We posted a web page, a YouTube video and an image with every combination of unfurl_links and unfurl_media on 1 October 2026, then built a custom preview with link_shared and chat.unfurl. The flags do not split the way the names suggest.

We scheduled five messages for 4:40 PM on 1 October 2026, then archived, left and deleted their channels and deleted a thread parent before the send time. Two sent, three never did, and Slack gave no notice about the three.

We broke a Slack bot nine ways on 1 October 2026, in Socket Mode and over HTTP, and wrote down what the person in Slack saw and what the app received each time. The table of causes, symptoms and fixes comes from those runs.

A Slack bot can DM a user by passing the user ID as the channel in chat.postMessage, or by opening the DM with conversations.open first. We ran both, recorded where each message landed, and reproduced messages_tab_disabled and 'Sending messages to this app has been turned off'.

We made a Slack Events API endpoint fail on purpose and logged every redelivery with its X-Slack-Retry-Num and X-Slack-Retry-Reason headers. Slack retried 3 times, at about 0 s, 1 minute and 6 minutes. Measured timing, what X-Slack-No-Retry does, and a handler that stops the retries.

Slack signs every request with your app's signing secret: HMAC-SHA256 of v0:timestamp:raw body. We verified a real slash command and a real event on 1 October 2026, then broke it the four ways apps break it.

A Slack message link is /archives/<channel>/p<ts without the dot>. We copied links in Slack web and called chat.getPermalink on 1 October 2026 to compare the formats for channel messages and thread replies, then turned links back into a channel and ts.